Pull RTC fix from Alexandre Belloni:
 "Fix regmap configuration for ds1307"

* tag 'rtc-4.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux:
  rtc: ds1307: fix regmap config

Pull networking fixes from David Miller:

 1) Fix IGMP handling wrt VRF, from David Ahern.

 2) Fix timer access to freed object in dccp, from Eric Dumazet.

 3) Use kmalloc_array() in ptr_ring to avoid overflow cases which are
    triggerable by userspace. Also from Eric Dumazet.

 4) Fix infinite loop in unmapping cleanup of nfp driver, from Colin Ian
    King.

 5) Correct datagram peek handling of empty SKBs, from Matthew Dawson.

 6) Fix use after free in TIPC, from Eric Dumazet.

 7) When replacing a route in ipv6 we need to reset the round robin
    pointer, from Wei Wang.

 8) Fix bug in pci_find_pcie_root_port() which was unearthed by the
    relaxed ordering changes, from Thierry Redding. I made sure to get
    an explicit ACK from Bjorn this time around :-)

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (27 commits)
  ipv6: repair fib6 tree in failure case
  net_sched: fix order of queue length updates in qdisc_replace()
  tools lib bpf: improve warning
  switchdev: documentation: minor typo fixes
  bpf, doc: also add s390x as arch to sysctl description
  net: sched: fix NULL pointer dereference when action calls some targets
  rxrpc: Fix oops when discarding a preallocated service call
  irda: do not leak initialized list.dev to userspace
  net/mlx4_core: Enable 4K UAR if SRIOV module parameter is not enabled
  PCI: Allow PCI express root ports to find themselves
  tcp: when rearming RTO, if RTO time is in past then fire RTO ASAP
  net: check and errout if res->fi is NULL when RTM_F_FIB_MATCH is set
  ipv6: reset fn->rr_ptr when replacing route
  sctp: fully initialize the IPv6 address in sctp_v6_to_addr()
  tipc: fix use-after-free
  tun: handle register_netdevice() failures properly
  datagram: When peeking datagrams with offset < 0 don't skip empty skbs
  bpf, doc: improve sysctl knob description
  netxen: fix incorrect loop counter decrement
  nfp: fix infinite loop on umapping cleanup
  ...

This was reported many times, and this was even mentioned in commit
52ee2dfd ("pids: refactor vnr/nr_ns helpers to make them safe") but
somehow nobody bothered to fix the obvious problem: task_tgid_nr_ns() is
not safe because task->group_leader points to nowhere after the exiting
task passes exit_notify(), rcu_read_lock() can not help.

We really need to change __unhash_process() to nullify group_leader,
parent, and real_parent, but this needs some cleanups.  Until then we
can turn task_tgid_nr_ns() into another user of __task_pid_nr_ns() and
fix the problem.
Reported-by: Troy Kensinger <tkensinger@google.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Current max_register setting breaks reading nvram on certain chips and
also reading the standard registers on RX8130 where register map starts
at 0x10.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Fixes: 11e5890b "rtc: ds1307: convert driver to regmap"
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

In fib6_add(), it is possible that fib6_add_1() picks an intermediate
node and sets the node's fn->leaf to NULL in order to add this new
route. However, if fib6_add_rt2node() fails to add the new
route for some reason, fn->leaf will be left as NULL and could
potentially cause crash when fn->leaf is accessed in fib6_locate().
This patch makes sure fib6_repair_tree() is called to properly repair
fn->leaf in the above failure case.

Here is the syzkaller reported general protection fault in fib6_locate:
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Modules linked in:
CPU: 0 PID: 40937 Comm: syz-executor3 Not tainted
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d7d64100 ti: ffff8801d01a0000 task.ti: ffff8801d01a0000
RIP: 0010:[<ffffffff82a3e0e1>]  [<ffffffff82a3e0e1>] __ipv6_prefix_equal64_half include/net/ipv6.h:475 [inline]
RIP: 0010:[<ffffffff82a3e0e1>]  [<ffffffff82a3e0e1>] ipv6_prefix_equal include/net/ipv6.h:492 [inline]
RIP: 0010:[<ffffffff82a3e0e1>]  [<ffffffff82a3e0e1>] fib6_locate_1 net/ipv6/ip6_fib.c:1210 [inline]
RIP: 0010:[<ffffffff82a3e0e1>]  [<ffffffff82a3e0e1>] fib6_locate+0x281/0x3c0 net/ipv6/ip6_fib.c:1233
RSP: 0018:ffff8801d01a36a8  EFLAGS: 00010202
RAX: 0000000000000020 RBX: ffff8801bc790e00 RCX: ffffc90002983000
RDX: 0000000000001219 RSI: ffff8801d01a37a0 RDI: 0000000000000100
RBP: ffff8801d01a36f0 R08: 00000000000000ff R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000001
R13: dffffc0000000000 R14: ffff8801d01a37a0 R15: 0000000000000000
FS:  00007f6afd68c700(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004c6340 CR3: 00000000ba41f000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801d01a37a8 ffff8801d01a3780 ffffed003a0346f5 0000000c82a23ea0
 ffff8800b7bd7700 ffff8801d01a3780 ffff8800b6a1c940 ffffffff82a23ea0
 ffff8801d01a3920 ffff8801d01a3748 ffffffff82a223d6 ffff8801d7d64988
Call Trace:
 [<ffffffff82a223d6>] ip6_route_del+0x106/0x570 net/ipv6/route.c:2109
 [<ffffffff82a23f9d>] inet6_rtm_delroute+0xfd/0x100 net/ipv6/route.c:3075
 [<ffffffff82621359>] rtnetlink_rcv_msg+0x549/0x7a0 net/core/rtnetlink.c:3450
 [<ffffffff8274c1d1>] netlink_rcv_skb+0x141/0x370 net/netlink/af_netlink.c:2281
 [<ffffffff82613ddf>] rtnetlink_rcv+0x2f/0x40 net/core/rtnetlink.c:3456
 [<ffffffff8274ad38>] netlink_unicast_kernel net/netlink/af_netlink.c:1206 [inline]
 [<ffffffff8274ad38>] netlink_unicast+0x518/0x750 net/netlink/af_netlink.c:1232
 [<ffffffff8274b83e>] netlink_sendmsg+0x8ce/0xc30 net/netlink/af_netlink.c:1778
 [<ffffffff82564aff>] sock_sendmsg_nosec net/socket.c:609 [inline]
 [<ffffffff82564aff>] sock_sendmsg+0xcf/0x110 net/socket.c:619
 [<ffffffff82564d62>] sock_write_iter+0x222/0x3a0 net/socket.c:834
 [<ffffffff8178523d>] new_sync_write+0x1dd/0x2b0 fs/read_write.c:478
 [<ffffffff817853f4>] __vfs_write+0xe4/0x110 fs/read_write.c:491
 [<ffffffff81786c38>] vfs_write+0x178/0x4b0 fs/read_write.c:538
 [<ffffffff817892a9>] SYSC_write fs/read_write.c:585 [inline]
 [<ffffffff817892a9>] SyS_write+0xd9/0x1b0 fs/read_write.c:577
 [<ffffffff82c71e32>] entry_SYSCALL_64_fastpath+0x12/0x17

Note: there is no "Fixes" tag as this seems to be a bug introduced
very early.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This important to call qdisc_tree_reduce_backlog() after changing queue
length. Parent qdisc should deactivate class in ->qlen_notify() called from
qdisc_tree_reduce_backlog() but this happens only if qdisc->q.qlen in zero.

Missed class deactivations leads to crashes/warnings at picking packets
from empty qdisc and corrupting state at reactivating this class in future.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Fixes: 86a7996c ("net_sched: introduce qdisc_replace() helper")
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Eric Leblond <eric@regit.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Two typos in switchdev.txt
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>

Looks like this was accidentally missed, so still add s390x
as supported eBPF JIT arch to bpf_jit_enable.

Fixes: 014cd0a3 ("bpf: Update sysctl documentation to list all supported architectures")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The 'move_paghes()' system call was introduced long long ago with the
same permission checks as for sending a signal (except using
CAP_SYS_NICE instead of CAP_SYS_KILL for the overriding capability).

That turns out to not be a great choice - while the system call really
only moves physical page allocations around (and you need other
capabilities to do a lot of it), you can check the return value to map
out some the virtual address choices and defeat ASLR of a binary that
still shares your uid.

So change the access checks to the more common 'ptrace_may_access()'
model instead.

This tightens the access checks for the uid, and also effectively
changes the CAP_SYS_NICE check to CAP_SYS_PTRACE, but it's unlikely that
anybody really _uses_ this legacy system call any more (we hav ebetter
NUMA placement models these days), so I expect nobody to notice.

Famous last words.
Reported-by: Otto Ebeling <otto.ebeling@iki.fi>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull x86 fixes from Thomas Gleixner:
 "Another pile of small fixes and updates for x86:

   - Plug a hole in the SMAP implementation which misses to clear AC on
     NMI entry

   - Fix the norandmaps/ADDR_NO_RANDOMIZE logic so the command line
     parameter works correctly again

   - Use the proper accessor in the startup64 code for next_early_pgt to
     prevent accessing of invalid addresses and faulting in the early
     boot code.

   - Prevent CPU hotplug lock recursion in the MTRR code

   - Unbreak CPU0 hotplugging

   - Rename overly long CPUID bits which got introduced in this cycle

   - Two commits which mark data 'const' and restrict the scope of data
     and functions to file scope by making them 'static'"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Constify attribute_group structures
  x86/boot/64/clang: Use fixup_pointer() to access 'next_early_pgt'
  x86/elf: Remove the unnecessary ADDR_NO_RANDOMIZE checks
  x86: Fix norandmaps/ADDR_NO_RANDOMIZE
  x86/mtrr: Prevent CPU hotplug lock recursion
  x86: Mark various structures and functions as 'static'
  x86/cpufeature, kvm/svm: Rename (shorten) the new "virtualized VMSAVE/VMLOAD" CPUID flag
  x86/smpboot: Unbreak CPU0 hotplug
  x86/asm/64: Clear AC on NMI entries

Pull timer fixes from Thomas Gleixner:
 "A few small fixes for timer drivers:

   - Prevent infinite recursion in the arm architected timer driver with
     ftrace

   - Propagate error codes to the caller in case of failure in EM STI
     driver

   - Adjust a bogus loop iteration in the arm architected timer driver

   - Add a missing Kconfig dependency to the pistachio clocksource to
     prevent build failures

   - Correctly check for IS_ERR() instead of NULL in the shared timer-of
     code"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/arm_arch_timer: Avoid infinite recursion when ftrace is enabled
  clocksource/drivers/Kconfig: Fix CLKSRC_PISTACHIO dependencies
  clocksource/drivers/timer-of: Checking for IS_ERR() instead of NULL
  clocksource/drivers/em_sti: Fix error return codes in em_sti_probe()
  clocksource/drivers/arm_arch_timer: Fix mem frame loop initialization

Pull perf fixes from Thomas Gleixner:
 "Two fixes for the perf subsystem:

   - Fix an inconsistency of RDPMC mm struct tagging across exec() which
     causes RDPMC to fault.

   - Correct the timestamp mechanics across IOC_DISABLE/ENABLE which
     causes incorrect timestamps and total time calculations"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix time on IOC_ENABLE
  perf/x86: Fix RDPMC vs. mm_struct tracking

Pull irq fixes from Thomas Gleixner:
 "A pile of smallish changes all over the place:

   - Add a missing ISB in the GIC V1 driver

   - Remove an ACPI version check in the GIC V3 ITS driver

   - Add the missing irq_pm_shutdown function for BRCMSTB-L2 to avoid
     spurious wakeups

   - Remove the artifical limitation of ITS instances to the number of
     NUMA nodes which prevents utilizing the ITS hardware correctly

   - Prevent a infinite parsing loop in the GIC-V3 ITS/MSI code

   - Honour the force affinity argument in the GIC-V3 driver which is
     required to make perf work correctly

   - Correctly report allocation failures in GIC-V2/V3 to avoid using
     half allocated and initialized interrupts.

   - Fixup checks against nr_cpu_ids in the generic IPI code"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/ipi: Fixup checks against nr_cpu_ids
  genirq: Restore trigger settings in irq_modify_status()
  MAINTAINERS: Remove Jason Cooper's irqchip git tree
  irqchip/gic-v3-its-platform-msi: Fix msi-parent parsing loop
  irqchip/gic-v3-its: Allow GIC ITS number more than MAX_NUMNODES
  irqchip: brcmstb-l2: Define an irq_pm_shutdown function
  irqchip/gic: Ensure we have an ISB between ack and ->handle_irq
  irqchip/gic-v3-its: Remove ACPICA version check for ACPI NUMA
  irqchip/gic-v3: Honor forced affinity setting
  irqchip/gic-v3: Report failures in gic_irq_domain_alloc
  irqchip/gic-v2: Report failures in gic_irq_domain_alloc
  irqchip/atmel-aic: Remove root argument from ->fixup() prototype
  irqchip/atmel-aic: Fix unbalanced refcount in aic_common_rtc_irq_fixup()
  irqchip/atmel-aic: Fix unbalanced of_node_put() in aic_common_irq_fixup()

Pull watchdog fix from Thomas Gleixner:
 "A fix for the hardlockup watchdog to prevent false positives with
  extreme Turbo-Modes which make the perf/NMI watchdog fire faster than
  the hrtimer which is used to verify.

  Slightly larger than the minimal fix, which just would increase the
  hrtimer frequency, but comes with extra overhead of more watchdog
  timer interrupts and thread wakeups for all users.

  With this change we restrict the overhead to the extreme Turbo-Mode
  systems"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kernel/watchdog: Prevent false positives with turbo modes

Valid CPU ids are [0, nr_cpu_ids-1] inclusive.

Fixes: 3b8e29a8 ("genirq: Implement ipi_send_mask/single()")
Fixes: f9bce791 ("genirq: Add a new function to get IPI reverse mapping")
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170819095751.GB27864@avx2

As we know in some target's checkentry it may dereference par.entryinfo
to check entry stuff inside. But when sched action calls xt_check_target,
par.entryinfo is set with NULL. It would cause kernel panic when calling
some targets.

It can be reproduce with:
  # tc qd add dev eth1 ingress handle ffff:
  # tc filter add dev eth1 parent ffff: u32 match u32 0 0 action xt \
    -j ECN --ecn-tcp-remove

It could also crash kernel when using target CLUSTERIP or TPROXY.

By now there's no proper value for par.entryinfo in ipt_init_target,
but it can not be set with NULL. This patch is to void all these
panics by setting it with an ipt_entry obj with all members = 0.

Note that this issue has been there since the very beginning.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

rxrpc_service_prealloc_one() doesn't set the socket pointer on any new call
it preallocates, but does add it to the rxrpc net namespace call list.
This, however, causes rxrpc_put_call() to oops when the call is discarded
when the socket is closed.  rxrpc_put_call() needs the socket to be able to
reach the namespace so that it can use a lock held therein.

Fix this by setting a call's socket pointer immediately before discarding
it.

This can be triggered by unloading the kafs module, resulting in an oops
like the following:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
IP: rxrpc_put_call+0x1e2/0x32d
PGD 0
P4D 0
Oops: 0000 [#1] SMP
Modules linked in: kafs(E-)
CPU: 3 PID: 3037 Comm: rmmod Tainted: G            E   4.12.0-fscache+ #213
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
task: ffff8803fc92e2c0 task.stack: ffff8803fef74000
RIP: 0010:rxrpc_put_call+0x1e2/0x32d
RSP: 0018:ffff8803fef77e08 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff8803fab99ac0 RCX: 000000000000000f
RDX: ffffffff81c50a40 RSI: 000000000000000c RDI: ffff8803fc92ea88
RBP: ffff8803fef77e30 R08: ffff8803fc87b941 R09: ffffffff82946d20
R10: ffff8803fef77d10 R11: 00000000000076fc R12: 0000000000000005
R13: ffff8803fab99c20 R14: 0000000000000001 R15: ffffffff816c6aee
FS:  00007f915a059700(0000) GS:ffff88041fb80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000030 CR3: 00000003fef39000 CR4: 00000000001406e0
Call Trace:
 rxrpc_discard_prealloc+0x325/0x341
 rxrpc_listen+0xf9/0x146
 kernel_listen+0xb/0xd
 afs_close_socket+0x3e/0x173 [kafs]
 afs_exit+0x1f/0x57 [kafs]
 SyS_delete_module+0x10f/0x19a
 do_syscall_64+0x8a/0x149
 entry_SYSCALL64_slow_path+0x25/0x25

Fixes: 2baec2c3 ("rxrpc: Support network namespacing")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

list.dev has not been initialized and so the copy_to_user is copying
data from the stack back to user space which is a potential
information leak. Fix this ensuring all of list is initialized to
zero.

Detected by CoverityScan, CID#1357894 ("Uninitialized scalar variable")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

enable_4k_uar module parameter was added in patch cited below to
address the backward compatibility issue in SRIOV when the VM has
system's PAGE_SIZE uar implementation and the Hypervisor has 4k uar
implementation.

The above compatibility issue does not exist in the non SRIOV case.
In this patch, we always enable 4k uar implementation if SRIOV
is not enabled on mlx4's supported cards.

Fixes: 76e39ccf ("net/mlx4_core: Fix backward compatibility on VFs")
Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If the pci_find_pcie_root_port() function is called on a root port
itself, return the root port rather than NULL.

This effectively reverts commit 0e405232 ("PCI: fix oops when
try to find Root Port for a PCI device") which added an extra check
that would now be redundant.

Fixes: a99b646a ("PCI: Disable PCIe Relaxed Ordering if unsupported")
Fixes: c56d4450 ("PCI: Turn off Request Attributes to avoid Chelsio T5 Completion erratum")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Shawn Lin <shawn.lin@rock-chips.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

In some situations tcp_send_loss_probe() can realize that it's unable
to send a loss probe (TLP), and falls back to calling tcp_rearm_rto()
to schedule an RTO timer. In such cases, sometimes tcp_rearm_rto()
realizes that the RTO was eligible to fire immediately or at some
point in the past (delta_us <= 0). Previously in such cases
tcp_rearm_rto() was scheduling such "overdue" RTOs to happen at now +
icsk_rto, which caused needless delays of hundreds of milliseconds
(and non-linear behavior that made reproducible testing
difficult). This commit changes the logic to schedule "overdue" RTOs
ASAP, rather than at now + icsk_rto.

Fixes: 6ba8a3b1 ("tcp: Tail loss probe (TLP)")
Suggested-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge misc fixes from Andrew Morton:
 "14 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: revert x86_64 and arm64 ELF_ET_DYN_BASE base changes
  mm/vmalloc.c: don't unconditonally use __GFP_HIGHMEM
  mm/mempolicy: fix use after free when calling get_mempolicy
  mm/cma_debug.c: fix stack corruption due to sprintf usage
  signal: don't remove SIGNAL_UNKILLABLE for traced tasks.
  mm, oom: fix potential data corruption when oom_reaper races with writer
  mm: fix double mmap_sem unlock on MMF_UNSTABLE enforced SIGBUS
  slub: fix per memcg cache leak on css offline
  mm: discard memblock data later
  test_kmod: fix description for -s -and -c parameters
  kmod: fix wait on recursive loop
  wait: add wait_event_killable_timeout()
  kernel/watchdog: fix Kconfig constraints for perf hardlockup watchdog
  mm: memcontrol: fix NULL pointer crash in test_clear_page_writeback()

Syzkaller hit 'general protection fault in fib_dump_info' bug on
commit 4.13-rc5..

Guilty file: net/ipv4/fib_semantics.c

kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Modules linked in:
CPU: 0 PID: 2808 Comm: syz-executor0 Not tainted 4.13.0-rc5 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
Ubuntu-1.8.2-1ubuntu1 04/01/2014
task: ffff880078562700 task.stack: ffff880078110000
RIP: 0010:fib_dump_info+0x388/0x1170 net/ipv4/fib_semantics.c:1314
RSP: 0018:ffff880078117010 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 00000000000000fe RCX: 0000000000000002
RDX: 0000000000000006 RSI: ffff880078117084 RDI: 0000000000000030
RBP: ffff880078117268 R08: 000000000000000c R09: ffff8800780d80c8
R10: 0000000058d629b4 R11: 0000000067fce681 R12: 0000000000000000
R13: ffff8800784bd540 R14: ffff8800780d80b5 R15: ffff8800780d80a4
FS:  00000000022fa940(0000) GS:ffff88007fc00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004387d0 CR3: 0000000079135000 CR4: 00000000000006f0
Call Trace:
  inet_rtm_getroute+0xc89/0x1f50 net/ipv4/route.c:2766
  rtnetlink_rcv_msg+0x288/0x680 net/core/rtnetlink.c:4217
  netlink_rcv_skb+0x340/0x470 net/netlink/af_netlink.c:2397
  rtnetlink_rcv+0x28/0x30 net/core/rtnetlink.c:4223
  netlink_unicast_kernel net/netlink/af_netlink.c:1265 [inline]
  netlink_unicast+0x4c4/0x6e0 net/netlink/af_netlink.c:1291
  netlink_sendmsg+0x8c4/0xca0 net/netlink/af_netlink.c:1854
  sock_sendmsg_nosec net/socket.c:633 [inline]
  sock_sendmsg+0xca/0x110 net/socket.c:643
  ___sys_sendmsg+0x779/0x8d0 net/socket.c:2035
  __sys_sendmsg+0xd1/0x170 net/socket.c:2069
  SYSC_sendmsg net/socket.c:2080 [inline]
  SyS_sendmsg+0x2d/0x50 net/socket.c:2076
  entry_SYSCALL_64_fastpath+0x1a/0xa5
  RIP: 0033:0x4512e9
  RSP: 002b:00007ffc75584cc8 EFLAGS: 00000216 ORIG_RAX:
  000000000000002e
  RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00000000004512e9
  RDX: 0000000000000000 RSI: 0000000020f2cfc8 RDI: 0000000000000003
  RBP: 000000000000000e R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000216 R12: fffffffffffffffe
  R13: 0000000000718000 R14: 0000000020c44ff0 R15: 0000000000000000
  Code: 00 0f b6 8d ec fd ff ff 48 8b 85 f0 fd ff ff 88 48 17 48 8b 45
  28 48 8d 78 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03
  <0f>
  b6 04 02 84 c0 74 08 3c 03 0f 8e cb 0c 00 00 48 8b 45 28 44
  RIP: fib_dump_info+0x388/0x1170 net/ipv4/fib_semantics.c:1314 RSP:
  ffff880078117010
---[ end trace 254a7af28348f88b ]---

This patch adds a res->fi NULL check.

example run:
$ip route get 0.0.0.0 iif virt1-0
broadcast 0.0.0.0 dev lo
    cache <local,brd> iif virt1-0

$ip route get 0.0.0.0 iif virt1-0 fibmatch
RTNETLINK answers: No route to host
Reported-by: idaifish <idaifish@gmail.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Fixes: b6179813 ("net: ipv4: RTM_GETROUTE: return matched fib result when requested")
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

syzcaller reported the following use-after-free issue in rt6_select():
BUG: KASAN: use-after-free in rt6_select net/ipv6/route.c:755 [inline] at addr ffff8800bc6994e8
BUG: KASAN: use-after-free in ip6_pol_route.isra.46+0x1429/0x1470 net/ipv6/route.c:1084 at addr ffff8800bc6994e8
Read of size 4 by task syz-executor1/439628
CPU: 0 PID: 439628 Comm: syz-executor1 Not tainted 4.3.5+ #8
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 ffff88018fe435b0 ffffffff81ca384d ffff8801d3588c00
 ffff8800bc699380 ffff8800bc699500 dffffc0000000000 ffff8801d40a47c0
 ffff88018fe435d8 ffffffff81735751 ffff88018fe43660 ffff8800bc699380
Call Trace:
 [<ffffffff81ca384d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81ca384d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
sctp: [Deprecated]: syz-executor0 (pid 439615) Use of struct sctp_assoc_value in delayed_ack socket option.
Use struct sctp_sack_info instead
 [<ffffffff81735751>] kasan_object_err+0x21/0x70 mm/kasan/report.c:158
 [<ffffffff817359c4>] print_address_description mm/kasan/report.c:196 [inline]
 [<ffffffff817359c4>] kasan_report_error+0x1b4/0x4a0 mm/kasan/report.c:285
 [<ffffffff81735d93>] kasan_report mm/kasan/report.c:305 [inline]
 [<ffffffff81735d93>] __asan_report_load4_noabort+0x43/0x50 mm/kasan/report.c:325
 [<ffffffff82a28e39>] rt6_select net/ipv6/route.c:755 [inline]
 [<ffffffff82a28e39>] ip6_pol_route.isra.46+0x1429/0x1470 net/ipv6/route.c:1084
 [<ffffffff82a28fb1>] ip6_pol_route_output+0x81/0xb0 net/ipv6/route.c:1203
 [<ffffffff82ab0a50>] fib6_rule_action+0x1f0/0x680 net/ipv6/fib6_rules.c:95
 [<ffffffff8265cbb6>] fib_rules_lookup+0x2a6/0x7a0 net/core/fib_rules.c:223
 [<ffffffff82ab1430>] fib6_rule_lookup+0xd0/0x250 net/ipv6/fib6_rules.c:41
 [<ffffffff82a22006>] ip6_route_output+0x1d6/0x2c0 net/ipv6/route.c:1224
 [<ffffffff829e83d2>] ip6_dst_lookup_tail+0x4d2/0x890 net/ipv6/ip6_output.c:943
 [<ffffffff829e889a>] ip6_dst_lookup_flow+0x9a/0x250 net/ipv6/ip6_output.c:1079
 [<ffffffff82a9f7d8>] ip6_datagram_dst_update+0x538/0xd40 net/ipv6/datagram.c:91
 [<ffffffff82aa0978>] __ip6_datagram_connect net/ipv6/datagram.c:251 [inline]
 [<ffffffff82aa0978>] ip6_datagram_connect+0x518/0xe50 net/ipv6/datagram.c:272
 [<ffffffff82aa1313>] ip6_datagram_connect_v6_only+0x63/0x90 net/ipv6/datagram.c:284
 [<ffffffff8292f790>] inet_dgram_connect+0x170/0x1f0 net/ipv4/af_inet.c:564
 [<ffffffff82565547>] SYSC_connect+0x1a7/0x2f0 net/socket.c:1582
 [<ffffffff8256a649>] SyS_connect+0x29/0x30 net/socket.c:1563
 [<ffffffff82c72032>] entry_SYSCALL_64_fastpath+0x12/0x17
Object at ffff8800bc699380, in cache ip6_dst_cache size: 384

The root cause of it is that in fib6_add_rt2node(), when it replaces an
existing route with the new one, it does not update fn->rr_ptr.
This commit resets fn->rr_ptr to NULL when it points to a route which is
replaced in fib6_add_rt2node().

Fixes: 27596472 ("ipv6: fix ECMP route replacement")
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

KMSAN reported use of uninitialized sctp_addr->v4.sin_addr.s_addr and
sctp_addr->v6.sin6_scope_id in sctp_v6_cmp_addr() (see below).
Make sure all fields of an IPv6 address are initialized, which
guarantees that the IPv4 fields are also initialized.

==================================================================
 BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
 net/sctp/ipv6.c:517
 CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
 01/01/2011
 Call Trace:
  dump_stack+0x172/0x1c0 lib/dump_stack.c:42
  is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
  kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
  native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
  arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
  arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
  __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
  sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
  sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
  sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
  sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
  sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
  inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
  sock_sendmsg_nosec net/socket.c:633 [inline]
  sock_sendmsg net/socket.c:643 [inline]
  SYSC_sendto+0x608/0x710 net/socket.c:1696
  SyS_sendto+0x8a/0xb0 net/socket.c:1664
  entry_SYSCALL_64_fastpath+0x13/0x94
 RIP: 0033:0x44b479
 RSP: 002b:00007f6213f21c08 EFLAGS: 00000286 ORIG_RAX: 000000000000002c
 RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 000000000044b479
 RDX: 0000000000000041 RSI: 0000000020edd000 RDI: 0000000000000006
 RBP: 00000000007080a8 R08: 0000000020b85fe4 R09: 000000000000001c
 R10: 0000000000040005 R11: 0000000000000286 R12: 00000000ffffffff
 R13: 0000000000003760 R14: 00000000006e5820 R15: 0000000000ff8000
 origin description: ----dst_saddr@sctp_v6_get_dst
 local variable created at:
  sk_fullsock include/net/sock.h:2321 [inline]
  inet6_sk include/linux/ipv6.h:309 [inline]
  sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
  sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
==================================================================
 BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
 net/sctp/ipv6.c:517
 CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
 01/01/2011
 Call Trace:
  dump_stack+0x172/0x1c0 lib/dump_stack.c:42
  is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
  kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
  native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
  arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
  arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
  __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
  sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
  sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
  sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
  sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
  sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
  inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
  sock_sendmsg_nosec net/socket.c:633 [inline]
  sock_sendmsg net/socket.c:643 [inline]
  SYSC_sendto+0x608/0x710 net/socket.c:1696
  SyS_sendto+0x8a/0xb0 net/socket.c:1664
  entry_SYSCALL_64_fastpath+0x13/0x94
 RIP: 0033:0x44b479
 RSP: 002b:00007f6213f21c08 EFLAGS: 00000286 ORIG_RAX: 000000000000002c
 RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 000000000044b479
 RDX: 0000000000000041 RSI: 0000000020edd000 RDI: 0000000000000006
 RBP: 00000000007080a8 R08: 0000000020b85fe4 R09: 000000000000001c
 R10: 0000000000040005 R11: 0000000000000286 R12: 00000000ffffffff
 R13: 0000000000003760 R14: 00000000006e5820 R15: 0000000000ff8000
 origin description: ----dst_saddr@sctp_v6_get_dst
 local variable created at:
  sk_fullsock include/net/sock.h:2321 [inline]
  inet6_sk include/linux/ipv6.h:309 [inline]
  sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
  sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
==================================================================
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

syszkaller reported use-after-free in tipc [1]

When msg->rep skb is freed, set the pointer to NULL,
so that caller does not free it again.

[1]

==================================================================
BUG: KASAN: use-after-free in skb_push+0xd4/0xe0 net/core/skbuff.c:1466
Read of size 8 at addr ffff8801c6e71e90 by task syz-executor5/4115

CPU: 1 PID: 4115 Comm: syz-executor5 Not tainted 4.13.0-rc4+ #32
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x24e/0x340 mm/kasan/report.c:409
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 skb_push+0xd4/0xe0 net/core/skbuff.c:1466
 tipc_nl_compat_recv+0x833/0x18f0 net/tipc/netlink_compat.c:1209
 genl_family_rcv_msg+0x7b7/0xfb0 net/netlink/genetlink.c:598
 genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:623
 netlink_rcv_skb+0x216/0x440 net/netlink/af_netlink.c:2397
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:634
 netlink_unicast_kernel net/netlink/af_netlink.c:1265 [inline]
 netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1291
 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1854
 sock_sendmsg_nosec net/socket.c:633 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:643
 sock_write_iter+0x31a/0x5d0 net/socket.c:898
 call_write_iter include/linux/fs.h:1743 [inline]
 new_sync_write fs/read_write.c:457 [inline]
 __vfs_write+0x684/0x970 fs/read_write.c:470
 vfs_write+0x189/0x510 fs/read_write.c:518
 SYSC_write fs/read_write.c:565 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:557
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x4512e9
RSP: 002b:00007f3bc8184c08 EFLAGS: 00000216 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 00000000004512e9
RDX: 0000000000000020 RSI: 0000000020fdb000 RDI: 0000000000000006
RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000216 R12: 00000000004b5e76
R13: 00007f3bc8184b48 R14: 00000000004b5e86 R15: 0000000000000000

Allocated by task 4115:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
 kmem_cache_alloc_node+0x13d/0x750 mm/slab.c:3651
 __alloc_skb+0xf1/0x740 net/core/skbuff.c:219
 alloc_skb include/linux/skbuff.h:903 [inline]
 tipc_tlv_alloc+0x26/0xb0 net/tipc/netlink_compat.c:148
 tipc_nl_compat_dumpit+0xf2/0x3c0 net/tipc/netlink_compat.c:248
 tipc_nl_compat_handle net/tipc/netlink_compat.c:1130 [inline]
 tipc_nl_compat_recv+0x756/0x18f0 net/tipc/netlink_compat.c:1199
 genl_family_rcv_msg+0x7b7/0xfb0 net/netlink/genetlink.c:598
 genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:623
 netlink_rcv_skb+0x216/0x440 net/netlink/af_netlink.c:2397
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:634
 netlink_unicast_kernel net/netlink/af_netlink.c:1265 [inline]
 netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1291
 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1854
 sock_sendmsg_nosec net/socket.c:633 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:643
 sock_write_iter+0x31a/0x5d0 net/socket.c:898
 call_write_iter include/linux/fs.h:1743 [inline]
 new_sync_write fs/read_write.c:457 [inline]
 __vfs_write+0x684/0x970 fs/read_write.c:470
 vfs_write+0x189/0x510 fs/read_write.c:518
 SYSC_write fs/read_write.c:565 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:557
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Freed by task 4115:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3503 [inline]
 kmem_cache_free+0x77/0x280 mm/slab.c:3763
 kfree_skbmem+0x1a1/0x1d0 net/core/skbuff.c:622
 __kfree_skb net/core/skbuff.c:682 [inline]
 kfree_skb+0x165/0x4c0 net/core/skbuff.c:699
 tipc_nl_compat_dumpit+0x36a/0x3c0 net/tipc/netlink_compat.c:260
 tipc_nl_compat_handle net/tipc/netlink_compat.c:1130 [inline]
 tipc_nl_compat_recv+0x756/0x18f0 net/tipc/netlink_compat.c:1199
 genl_family_rcv_msg+0x7b7/0xfb0 net/netlink/genetlink.c:598
 genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:623
 netlink_rcv_skb+0x216/0x440 net/netlink/af_netlink.c:2397
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:634
 netlink_unicast_kernel net/netlink/af_netlink.c:1265 [inline]
 netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1291
 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1854
 sock_sendmsg_nosec net/socket.c:633 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:643
 sock_write_iter+0x31a/0x5d0 net/socket.c:898
 call_write_iter include/linux/fs.h:1743 [inline]
 new_sync_write fs/read_write.c:457 [inline]
 __vfs_write+0x684/0x970 fs/read_write.c:470
 vfs_write+0x189/0x510 fs/read_write.c:518
 SYSC_write fs/read_write.c:565 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:557
 entry_SYSCALL_64_fastpath+0x1f/0xbe

The buggy address belongs to the object at ffff8801c6e71dc0
 which belongs to the cache skbuff_head_cache of size 224
The buggy address is located 208 bytes inside of
 224-byte region [ffff8801c6e71dc0, ffff8801c6e71ea0)
The buggy address belongs to the page:
page:ffffea00071b9c40 count:1 mapcount:0 mapping:ffff8801c6e71000 index:0x0
flags: 0x200000000000100(slab)
raw: 0200000000000100 ffff8801c6e71000 0000000000000000 000000010000000c
raw: ffffea0007224a20 ffff8801d98caf48 ffff8801d9e79040 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c6e71d80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff8801c6e71e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801c6e71e80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
                         ^
 ffff8801c6e71f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801c6e71f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov  <dvyukov@google.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

syzkaller reported a double free [1], caused by the fact
that tun driver was not updated properly when priv_destructor
was added.

When/if register_netdevice() fails, priv_destructor() must have been
called already.

[1]
BUG: KASAN: double-free or invalid-free in selinux_tun_dev_free_security+0x15/0x20 security/selinux/hooks.c:5023

CPU: 0 PID: 2919 Comm: syzkaller227220 Not tainted 4.13.0-rc4+ #23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 print_address_description+0x7f/0x260 mm/kasan/report.c:252
 kasan_report_double_free+0x55/0x80 mm/kasan/report.c:333
 kasan_slab_free+0xa0/0xc0 mm/kasan/kasan.c:514
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xd3/0x260 mm/slab.c:3820
 selinux_tun_dev_free_security+0x15/0x20 security/selinux/hooks.c:5023
 security_tun_dev_free_security+0x48/0x80 security/security.c:1512
 tun_set_iff drivers/net/tun.c:1884 [inline]
 __tun_chr_ioctl+0x2ce6/0x3d50 drivers/net/tun.c:2064
 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2309
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x443ff9
RSP: 002b:00007ffc34271f68 EFLAGS: 00000217 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443ff9
RDX: 0000000020533000 RSI: 00000000400454ca RDI: 0000000000000003
RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000401ce0
R13: 0000000000401d70 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 2919:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:551
 kmem_cache_alloc_trace+0x101/0x6f0 mm/slab.c:3627
 kmalloc include/linux/slab.h:493 [inline]
 kzalloc include/linux/slab.h:666 [inline]
 selinux_tun_dev_alloc_security+0x49/0x170 security/selinux/hooks.c:5012
 security_tun_dev_alloc_security+0x6d/0xa0 security/security.c:1506
 tun_set_iff drivers/net/tun.c:1839 [inline]
 __tun_chr_ioctl+0x1730/0x3d50 drivers/net/tun.c:2064
 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2309
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Freed by task 2919:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x6e/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xd3/0x260 mm/slab.c:3820
 selinux_tun_dev_free_security+0x15/0x20 security/selinux/hooks.c:5023
 security_tun_dev_free_security+0x48/0x80 security/security.c:1512
 tun_free_netdev+0x13b/0x1b0 drivers/net/tun.c:1563
 register_netdevice+0x8d0/0xee0 net/core/dev.c:7605
 tun_set_iff drivers/net/tun.c:1859 [inline]
 __tun_chr_ioctl+0x1caf/0x3d50 drivers/net/tun.c:2064
 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2309
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xbe

The buggy address belongs to the object at ffff8801d2843b40
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8801d2843b40, ffff8801d2843b60)
The buggy address belongs to the page:
page:ffffea000660cea8 count:1 mapcount:0 mapping:ffff8801d2843000 index:0xffff8801d2843fc1
flags: 0x200000000000100(slab)
raw: 0200000000000100 ffff8801d2843000 ffff8801d2843fc1 000000010000003f
raw: ffffea0006626a40 ffffea00066141a0 ffff8801dbc00100
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d2843a00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d2843a80: 00 00 00 fc fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801d2843b00: 00 00 00 00 fc fc fc fc fb fb fb fb fc fc fc fc
                                           ^
 ffff8801d2843b80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d2843c00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc

==================================================================

Fixes: cf124db5 ("net: Fix inconsistent teardown and release of private netdev state.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Moving the x86_64 and arm64 PIE base from 0x555555554000 to 0x000100000000
broke AddressSanitizer.  This is a partial revert of:

  eab09532 ("binfmt_elf: use ELF_ET_DYN_BASE only for PIE")
  02445990 ("arm64: move ELF_ET_DYN_BASE to 4GB / 4MB")

The AddressSanitizer tool has hard-coded expectations about where
executable mappings are loaded.

The motivation for changing the PIE base in the above commits was to
avoid the Stack-Clash CVEs that allowed executable mappings to get too
close to heap and stack.  This was mainly a problem on 32-bit, but the
64-bit bases were moved too, in an effort to proactively protect those
systems (proofs of concept do exist that show 64-bit collisions, but
other recent changes to fix stack accounting and setuid behaviors will
minimize the impact).

The new 32-bit PIE base is fine for ASan (since it matches the ET_EXEC
base), so only the 64-bit PIE base needs to be reverted to let x86 and
arm64 ASan binaries run again.  Future changes to the 64-bit PIE base on
these architectures can be made optional once a more dynamic method for
dealing with AddressSanitizer is found.  (e.g.  always loading PIE into
the mmap region for marked binaries.)

Link: http://lkml.kernel.org/r/20170807201542.GA21271@beast
Fixes: eab09532 ("binfmt_elf: use ELF_ET_DYN_BASE only for PIE")
Fixes: 02445990 ("arm64: move ELF_ET_DYN_BASE to 4GB / 4MB")
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Kostya Serebryany <kcc@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 19809c2d ("mm, vmalloc: use __GFP_HIGHMEM implicitly") added
use of __GFP_HIGHMEM for allocations.  vmalloc_32 may use
GFP_DMA/GFP_DMA32 which does not play nice with __GFP_HIGHMEM and will
trigger a BUG in gfp_zone.

Only add __GFP_HIGHMEM if we aren't using GFP_DMA/GFP_DMA32.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1482249
Link: http://lkml.kernel.org/r/20170816220705.31374-1-labbott@redhat.com
Fixes: 19809c2d ("mm, vmalloc: use __GFP_HIGHMEM implicitly")
Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

I hit a use after free issue when executing trinity and repoduced it
with KASAN enabled.  The related call trace is as follows.

  BUG: KASan: use after free in SyS_get_mempolicy+0x3c8/0x960 at addr ffff8801f582d766
  Read of size 2 by task syz-executor1/798

  INFO: Allocated in mpol_new.part.2+0x74/0x160 age=3 cpu=1 pid=799
     __slab_alloc+0x768/0x970
     kmem_cache_alloc+0x2e7/0x450
     mpol_new.part.2+0x74/0x160
     mpol_new+0x66/0x80
     SyS_mbind+0x267/0x9f0
     system_call_fastpath+0x16/0x1b
  INFO: Freed in __mpol_put+0x2b/0x40 age=4 cpu=1 pid=799
     __slab_free+0x495/0x8e0
     kmem_cache_free+0x2f3/0x4c0
     __mpol_put+0x2b/0x40
     SyS_mbind+0x383/0x9f0
     system_call_fastpath+0x16/0x1b
  INFO: Slab 0xffffea0009cb8dc0 objects=23 used=8 fp=0xffff8801f582de40 flags=0x200000000004080
  INFO: Object 0xffff8801f582d760 @offset=5984 fp=0xffff8801f582d600

  Bytes b4 ffff8801f582d750: ae 01 ff ff 00 00 00 00 5a 5a 5a 5a 5a 5a 5a 5a  ........ZZZZZZZZ
  Object ffff8801f582d760: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
  Object ffff8801f582d770: 6b 6b 6b 6b 6b 6b 6b a5                          kkkkkkk.
  Redzone ffff8801f582d778: bb bb bb bb bb bb bb bb                          ........
  Padding ffff8801f582d8b8: 5a 5a 5a 5a 5a 5a 5a 5a                          ZZZZZZZZ
  Memory state around the buggy address:
  ffff8801f582d600: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffff8801f582d680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  >ffff8801f582d700: fc fc fc fc fc fc fc fc fc fc fc fc fb fb fb fc

!shared memory policy is not protected against parallel removal by other
thread which is normally protected by the mmap_sem.  do_get_mempolicy,
however, drops the lock midway while we can still access it later.

Early premature up_read is a historical artifact from times when
put_user was called in this path see https://lwn.net/Articles/124754/
but that is gone since 8bccd85f ("[PATCH] Implement sys_* do_*
layering in the memory policy layer.").  but when we have the the
current mempolicy ref count model.  The issue was introduced
accordingly.

Fix the issue by removing the premature release.

Link: http://lkml.kernel.org/r/1502950924-27521-1-git-send-email-zhongjiang@huawei.comSigned-off-by: zhong jiang <zhongjiang@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>	[2.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

name[] in cma_debugfs_add_one() can only accommodate 16 chars including
NULL to store sprintf output.  It's common for cma device name to be
larger than 15 chars.  This can cause stack corrpution.  If the gcc
stack protector is turned on, this can cause a panic due to stack
corruption.

Below is one example trace:

  Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in:
  ffffff8e69a75730
  Call trace:
     dump_backtrace+0x0/0x2c4
     show_stack+0x20/0x28
     dump_stack+0xb8/0xf4
     panic+0x154/0x2b0
     print_tainted+0x0/0xc0
     cma_debugfs_init+0x274/0x290
     do_one_initcall+0x5c/0x168
     kernel_init_freeable+0x1c8/0x280

Fix the short sprintf buffer in cma_debugfs_add_one() by using
scnprintf() instead of sprintf().

Link: http://lkml.kernel.org/r/1502446217-21840-1-git-send-email-guptap@codeaurora.org
Fixes: f318dd08 ("cma: Store a name in the cma structure")
Signed-off-by: Prakash Gupta <guptap@codeaurora.org>
Acked-by: Laura Abbott <labbott@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When forcing a signal, SIGNAL_UNKILLABLE is removed to prevent recursive
faults, but this is undesirable when tracing.  For example, debugging an
init process (whether global or namespace), hitting a breakpoint and
SIGTRAP will force SIGTRAP and then remove SIGNAL_UNKILLABLE.
Everything continues fine, but then once debugging has finished, the
init process is left killable which is unlikely what the user expects,
resulting in either an accidentally killed init or an init that stops
reaping zombies.

Link: http://lkml.kernel.org/r/20170815112806.10728-1-jamie.iles@oracle.comSigned-off-by: Jamie Iles <jamie.iles@oracle.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Wenwei Tao has noticed that our current assumption that the oom victim
is dying and never doing any visible changes after it dies, and so the
oom_reaper can tear it down, is not entirely true.

__task_will_free_mem consider a task dying when SIGNAL_GROUP_EXIT is set
but do_group_exit sends SIGKILL to all threads _after_ the flag is set.
So there is a race window when some threads won't have
fatal_signal_pending while the oom_reaper could start unmapping the
address space.  Moreover some paths might not check for fatal signals
before each PF/g-u-p/copy_from_user.

We already have a protection for oom_reaper vs.  PF races by checking
MMF_UNSTABLE.  This has been, however, checked only for kernel threads
(use_mm users) which can outlive the oom victim.  A simple fix would be
to extend the current check in handle_mm_fault for all tasks but that
wouldn't be sufficient because the current check assumes that a kernel
thread would bail out after EFAULT from get_user*/copy_from_user and
never re-read the same address which would succeed because the PF path
has established page tables already.  This seems to be the case for the
only existing use_mm user currently (virtio driver) but it is rather
fragile in general.

This is even more fragile in general for more complex paths such as
generic_perform_write which can re-read the same address more times
(e.g.  iov_iter_copy_from_user_atomic to fail and then
iov_iter_fault_in_readable on retry).

Therefore we have to implement MMF_UNSTABLE protection in a robust way
and never make a potentially corrupted content visible.  That requires
to hook deeper into the PF path and check for the flag _every time_
before a pte for anonymous memory is established (that means all
!VM_SHARED mappings).

The corruption can be triggered artificially
(http://lkml.kernel.org/r/201708040646.v746kkhC024636@www262.sakura.ne.jp)
but there doesn't seem to be any real life bug report.  The race window
should be quite tight to trigger most of the time.

Link: http://lkml.kernel.org/r/20170807113839.16695-3-mhocko@kernel.org
Fixes: aac45363 ("mm, oom: introduce oom reaper")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Wenwei Tao <wenwei.tww@alibaba-inc.com>
Tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andrea Argangeli <andrea@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Tetsuo Handa has noticed that MMF_UNSTABLE SIGBUS path in
handle_mm_fault causes a lockdep splat

  Out of memory: Kill process 1056 (a.out) score 603 or sacrifice child
  Killed process 1056 (a.out) total-vm:4268108kB, anon-rss:2246048kB, file-rss:0kB, shmem-rss:0kB
  a.out (1169) used greatest stack depth: 11664 bytes left
  DEBUG_LOCKS_WARN_ON(depth <= 0)
  ------------[ cut here ]------------
  WARNING: CPU: 6 PID: 1339 at kernel/locking/lockdep.c:3617 lock_release+0x172/0x1e0
  CPU: 6 PID: 1339 Comm: a.out Not tainted 4.13.0-rc3-next-20170803+ #142
  Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015
  RIP: 0010:lock_release+0x172/0x1e0
  Call Trace:
     up_read+0x1a/0x40
     __do_page_fault+0x28e/0x4c0
     do_page_fault+0x30/0x80
     page_fault+0x28/0x30

The reason is that the page fault path might have dropped the mmap_sem
and returned with VM_FAULT_RETRY.  MMF_UNSTABLE check however rewrites
the error path to VM_FAULT_SIGBUS and we always expect mmap_sem taken in
that path.  Fix this by taking mmap_sem when VM_FAULT_RETRY is held in
the MMF_UNSTABLE path.

We cannot simply add VM_FAULT_SIGBUS to the existing error code because
all arch specific page fault handlers and g-u-p would have to learn a
new error code combination.

Link: http://lkml.kernel.org/r/20170807113839.16695-2-mhocko@kernel.org
Fixes: 3f70dc38 ("mm: make sure that kthreads will not refault oom reaped memory")
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Andrea Argangeli <andrea@kernel.org>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Wenwei Tao <wenwei.tww@alibaba-inc.com>
Cc: <stable@vger.kernel.org>	[4.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

To avoid a possible deadlock, sysfs_slab_remove() schedules an
asynchronous work to delete sysfs entries corresponding to the kmem
cache.  To ensure the cache isn't freed before the work function is
called, it takes a reference to the cache kobject.  The reference is
supposed to be released by the work function.

However, the work function (sysfs_slab_remove_workfn()) does nothing in
case the cache sysfs entry has already been deleted, leaking the kobject
and the corresponding cache.

This may happen on a per memcg cache destruction, because sysfs entries
of a per memcg cache are deleted on memcg offline if the cache is empty
(see __kmemcg_cache_deactivate()).

The kmemleak report looks like this:

  unreferenced object 0xffff9f798a79f540 (size 32):
    comm "kworker/1:4", pid 15416, jiffies 4307432429 (age 28687.554s)
    hex dump (first 32 bytes):
      6b 6d 61 6c 6c 6f 63 2d 31 36 28 31 35 39 39 3a  kmalloc-16(1599:
      6e 65 77 72 6f 6f 74 29 00 23 6b c0 ff ff ff ff  newroot).#k.....
    backtrace:
       kmemleak_alloc+0x4a/0xa0
       __kmalloc_track_caller+0x148/0x2c0
       kvasprintf+0x66/0xd0
       kasprintf+0x49/0x70
       memcg_create_kmem_cache+0xe6/0x160
       memcg_kmem_cache_create_func+0x20/0x110
       process_one_work+0x205/0x5d0
       worker_thread+0x4e/0x3a0
       kthread+0x109/0x140
       ret_from_fork+0x2a/0x40
  unreferenced object 0xffff9f79b6136840 (size 416):
    comm "kworker/1:4", pid 15416, jiffies 4307432429 (age 28687.573s)
    hex dump (first 32 bytes):
      40 fb 80 c2 3e 33 00 00 00 00 00 40 00 00 00 00  @...>3.....@....
      00 00 00 00 00 00 00 00 10 00 00 00 10 00 00 00  ................
    backtrace:
       kmemleak_alloc+0x4a/0xa0
       kmem_cache_alloc+0x128/0x280
       create_cache+0x3b/0x1e0
       memcg_create_kmem_cache+0x118/0x160
       memcg_kmem_cache_create_func+0x20/0x110
       process_one_work+0x205/0x5d0
       worker_thread+0x4e/0x3a0
       kthread+0x109/0x140
       ret_from_fork+0x2a/0x40

Fix the leak by adding the missing call to kobject_put() to
sysfs_slab_remove_workfn().

Link: http://lkml.kernel.org/r/20170812181134.25027-1-vdavydov.dev@gmail.com
Fixes: 3b7b3140 ("slub: make sysfs file removal asynchronous")
Signed-off-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Reported-by: Andrei Vagin <avagin@gmail.com>
Tested-by: Andrei Vagin <avagin@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>	[4.12.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There is existing use after free bug when deferred struct pages are
enabled:

The memblock_add() allocates memory for the memory array if more than
128 entries are needed.  See comment in e820__memblock_setup():

  * The bootstrap memblock region count maximum is 128 entries
  * (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries
  * than that - so allow memblock resizing.

This memblock memory is freed here:
        free_low_memory_core_early()

We access the freed memblock.memory later in boot when deferred pages
are initialized in this path:

        deferred_init_memmap()
                for_each_mem_pfn_range()
                  __next_mem_pfn_range()
                    type = &memblock.memory;

One possible explanation for why this use-after-free hasn't been hit
before is that the limit of INIT_MEMBLOCK_REGIONS has never been
exceeded at least on systems where deferred struct pages were enabled.

Tested by reducing INIT_MEMBLOCK_REGIONS down to 4 from the current 128,
and verifying in qemu that this code is getting excuted and that the
freed pages are sane.

Link: http://lkml.kernel.org/r/1502485554-318703-2-git-send-email-pasha.tatashin@oracle.com
Fixes: 7e18adb4 ("mm: meminit: initialise remaining struct pages in parallel with kswapd")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The descriptions were reversed, correct this.

Link: http://lkml.kernel.org/r/20170809234635.13443-4-mcgrof@kernel.org
Fixes: 64b67120 ("test_sysctl: add generic script to expand on tests")
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Reported-by: Daniel Mentz <danielmentz@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matt Redfearn <matt.redfearn@imgetc.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Michal Marek <mmarek@suse.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Recursive loops with module loading were previously handled in kmod by
restricting the number of modprobe calls to 50 and if that limit was
breached request_module() would return an error and a user would see the
following on their kernel dmesg:

  request_module: runaway loop modprobe binfmt-464c
  Starting init:/sbin/init exists but couldn't execute it (error -8)

This issue could happen for instance when a 64-bit kernel boots a 32-bit
userspace on some architectures and has no 32-bit binary format
hanlders.  This is visible, for instance, when a CONFIG_MODULES enabled
64-bit MIPS kernel boots a into o32 root filesystem and the binfmt
handler for o32 binaries is not built-in.

After commit 6d7964a7 ("kmod: throttle kmod thread limit") we now
don't have any visible signs of an error and the kernel just waits for
the loop to end somehow.

Although this *particular* recursive loop could also be addressed by
doing a sanity check on search_binary_handler() and disallowing a
modular binfmt to be required for modprobe, a generic solution for any
recursive kernel kmod issues is still needed.

This should catch these loops.  We can investigate each loop and address
each one separately as they come in, this however puts a stop gap for
them as before.

Link: http://lkml.kernel.org/r/20170809234635.13443-3-mcgrof@kernel.org
Fixes: 6d7964a7 ("kmod: throttle kmod thread limit")
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Reported-by: Matt Redfearn <matt.redfearn@imgtec.com>
Tested-by: Matt Redfearn <matt.redfearn@imgetc.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Daniel Mentz <danielmentz@google.com>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michal Marek <mmarek@suse.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>