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  1. 06 Jul, 2022 6 commits
    • Al Viro's avatar
      step_into(): move fetching ->d_inode past handle_mounts() · 3bd8bc89
      Al Viro authored 
      ... and lose messing with it in __follow_mount_rcu()
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      3bd8bc89
    • Al Viro's avatar
      lookup_fast(): don't bother with inode · 4cb64024
      Al Viro authored 
      Note that validation of ->d_seq after ->d_inode fetch is gone, along
with fetching of ->d_inode itself.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      4cb64024
    • Al Viro's avatar
      follow_dotdot{,_rcu}(): don't bother with inode · b16c001d
      Al Viro authored 
      step_into() will fetch it, TYVM.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      b16c001d
    • Al Viro's avatar
      step_into(): lose inode argument · a4f5b521
      Al Viro authored 
      make handle_mounts() always fetch it.  This is just the first step -
the callers of step_into() will stop trying to calculate the sucker,
etc.

The passed value should be equal to dentry->d_inode in all cases;
in RCU mode - fetched after we'd sampled ->d_seq.  Might as well
fetch it here.  We do need to validate ->d_seq, which duplicates
the check currently done in lookup_fast(); that duplication will
go away shortly.

After that change handle_mounts() always ignores the initial value of
*inode and always sets it on success.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      a4f5b521
    • Al Viro's avatar
      namei: stash the sampled ->d_seq into nameidata · 03fa86e9
      Al Viro authored 
      New field: nd->next_seq.  Set to 0 outside of RCU mode, holds the sampled
value for the next dentry to be considered.  Used instead of an arseload
of local variables, arguments, etc.

step_into() has lost seq argument; nd->next_seq is used, so dentry passed
to it must be the one ->next_seq is about.

There are two requirements for RCU pathwalk:
	1) it should not give a hard failure (other than -ECHILD) unless
non-RCU pathwalk might fail that way given suitable timings.
	2) it should not succeed unless non-RCU pathwalk might succeed
with the same end location given suitable timings.

The use of seq numbers is the way we achieve that.  Invariant we want
to maintain is:
	if RCU pathwalk can reach the state with given nd->path, nd->inode
and nd->seq after having traversed some part of pathname, it must be possible
for non-RCU pathwalk to reach the same nd->path and nd->inode after having
traversed the same part of pathname, and observe the nd->path.dentry->d_seq
equal to what RCU pathwalk has in nd->seq

	For transition from parent to child, we sample child's ->d_seq
and verify that parent's ->d_seq remains unchanged.  Anything that
disrupts parent-child relationship would've bumped ->d_seq on both.
	For transitions from child to parent we sample parent's ->d_seq
and verify that child's ->d_seq has not changed.  Same reasoning as
for the previous case applies.
	For transition from mountpoint to root of mounted we sample
the ->d_seq of root and verify that nobody has touched mount_lock since
the beginning of pathwalk.  That guarantees that mount we'd found had
been there all along, with these mountpoint and root of the mounted.
It would be possible for a non-RCU pathwalk to reach the previous state,
find the same mount and observe its root at the moment we'd sampled
->d_seq of that
	For transitions from root of mounted to mountpoint we sample
->d_seq of mountpoint and verify that mount_lock had not been touched
since the beginning of pathwalk.  The same reasoning as in the
previous case applies.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      03fa86e9
    • Al Viro's avatar
      namei: move clearing LOOKUP_RCU towards rcu_read_unlock() · 6e180327
      Al Viro authored 
      try_to_unlazy()/try_to_unlazy_next() drop LOOKUP_RCU in the
very beginning and do rcu_read_unlock() only at the very end.
However, nothing done in between even looks at the flag in
question; might as well clear it at the same time we unlock.

Note that try_to_unlazy_next() used to call legitimize_mnt(),
which might drop/regain rcu_read_lock() in some cases.  This
is no longer true, so we really have rcu_read_lock() held
all along until the end.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      6e180327
  3. 05 Jul, 2022 4 commits
    • Al Viro's avatar
      switch try_to_unlazy_next() to __legitimize_mnt() · 7e4745a0
      Al Viro authored 
      The tricky case (__legitimize_mnt() failing after having grabbed
a reference) can be trivially dealt with by leaving nd->path.mnt
non-NULL, for terminate_walk() to drop it.

legitimize_mnt() becomes static after that.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      7e4745a0
    • Al Viro's avatar
      follow_dotdot{,_rcu}(): change calling conventions · 51c6546c
      Al Viro authored 
      Instead of returning NULL when we are in root, just make it return
the current position (and set *seqp and *inodep accordingly).
That collapses the calls of step_into() in handle_dots()
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      51c6546c
    • Al Viro's avatar
      namei: get rid of pointless unlikely(read_seqcount_retry(...)) · 82ef0698
      Al Viro authored 
      read_seqcount_retry() et.al. are inlined and there's enough annotations
for compiler to figure out that those are unlikely to return non-zero.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      82ef0698
    • Al Viro's avatar
      __follow_mount_rcu(): verify that mount_lock remains unchanged · 20aac6c6
      Al Viro authored 
      Validate mount_lock seqcount as soon as we cross into mount in RCU
mode.  Sure, ->mnt_root is pinned and will remain so until we
do rcu_read_unlock() anyway, and we will eventually fail to unlazy if
the mount_lock had been touched, but we might run into a hard error
(e.g. -ENOENT) before trying to unlazy.  And it's possible to end
up with RCU pathwalk racing with rename() and umount() in a way
that would fail with -ENOENT while non-RCU pathwalk would've
succeeded with any timings.

Once upon a time we hadn't needed that, but analysis had been subtle,
brittle and went out of window as soon as RENAME_EXCHANGE had been
added.

It's narrow, hard to hit and won't get you anything other than
stray -ENOENT that could be arranged in much easier way with the
same priveleges, but it's a bug all the same.

Cc: stable@kernel.org
X-sky-is-falling: unlikely
Fixes: da1ce067 "vfs: add cross-rename"
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      20aac6c6
  5. 12 Jun, 2022 10 commits
  7. 11 Jun, 2022 9 commits
    • Linus Torvalds's avatar
      Merge tag 'gpio-fixes-for-v5.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux · 7a68065e
      Linus Torvalds authored 
      Pull gpio fixes from Bartosz Golaszewski:
 "A set of fixes. Most address the new warning we emit at build time
  when irq chips are not immutable with some additional tweaks to
  gpio-crystalcove from Andy and a small tweak to gpio-dwapd.

   - make irq_chip structs immutable in several Diolan and intel drivers
     to get rid of the new warning we emit when fiddling with irq chips

   - don't print error messages on probe deferral in gpio-dwapb"

* tag 'gpio-fixes-for-v5.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpio: dwapb: Don't print error on -EPROBE_DEFER
  gpio: dln2: make irq_chip immutable
  gpio: sch: make irq_chip immutable
  gpio: merrifield: make irq_chip immutable
  gpio: wcove: make irq_chip immutable
  gpio: crystalcove: Join function declarations and long lines
  gpio: crystalcove: Use specific type and API for IRQ number
  gpio: crystalcove: make irq_chip immutable
      7a68065e
    • Linus Torvalds's avatar
      Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · cecb3540
      Linus Torvalds authored 
      Pull SCSI fixes from James Bottomley:
 "Driver fixes and and one core patch.

  Nine of the driver patches are minor fixes and reworks to lpfc and the
  rest are trivial and minor fixes elsewhere"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: pmcraid: Fix missing resource cleanup in error case
  scsi: ipr: Fix missing/incorrect resource cleanup in error case
  scsi: mpt3sas: Fix out-of-bounds compiler warning
  scsi: lpfc: Update lpfc version to 14.2.0.4
  scsi: lpfc: Allow reduced polling rate for nvme_admin_async_event cmd completion
  scsi: lpfc: Add more logging of cmd and cqe information for aborted NVMe cmds
  scsi: lpfc: Fix port stuck in bypassed state after LIP in PT2PT topology
  scsi: lpfc: Resolve NULL ptr dereference after an ELS LOGO is aborted
  scsi: lpfc: Address NULL pointer dereference after starget_to_rport()
  scsi: lpfc: Resolve some cleanup issues following SLI path refactoring
  scsi: lpfc: Resolve some cleanup issues following abort path refactoring
  scsi: lpfc: Correct BDE type for XMIT_SEQ64_WQE in lpfc_ct_reject_event()
  scsi: vmw_pvscsi: Expand vcpuHint to 16 bits
  scsi: sd: Fix interpretation of VPD B9h length
      cecb3540
    • Linus Torvalds's avatar
      Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost · abe71eb3
      Linus Torvalds authored 
      Pull virtio fixes from Michael Tsirkin:
 "Fixes all over the place, most notably fixes for latent bugs in
  drivers that got exposed by suppressing interrupts before DRIVER_OK,
  which in turn has been done by 8b4ec69d ("virtio: harden vring
  IRQ")"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  um: virt-pci: set device ready in probe()
  vdpa: make get_vq_group and set_group_asid optional
  virtio: Fix all occurences of the "the the" typo
  vduse: Fix NULL pointer dereference on sysfs access
  vringh: Fix loop descriptors check in the indirect cases
  vdpa/mlx5: clean up indenting in handle_ctrl_vlan()
  vdpa/mlx5: fix error code for deleting vlan
  virtio-mmio: fix missing put_device() when vm_cmdline_parent registration failed
  vdpa/mlx5: Fix syntax errors in comments
  virtio-rng: make device ready before making request
      abe71eb3
    • Linus Torvalds's avatar
      Merge tag 'loongarch-fixes-5.19-1' of... · 0678afa6
      Linus Torvalds authored 
      Merge tag 'loongarch-fixes-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch fixes from Huacai Chen.
 "Fix build errors and a stale comment"

* tag 'loongarch-fixes-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: Remove MIPS comment about cycle counter
  LoongArch: Fix copy_thread() build errors
  LoongArch: Fix the !CONFIG_SMP build
      0678afa6
    • Linus Torvalds's avatar
      iov_iter: fix build issue due to possible type mis-match · 1c27f1fc
      Linus Torvalds authored 
      Commit 6c776766 ("iov_iter: Fix iter_xarray_get_pages{,_alloc}()")
introduced a problem on some 32-bit architectures (at least arm, xtensa,
csky,sparc and mips), that have a 'size_t' that is 'unsigned int'.

The reason is that we now do

    min(nr * PAGE_SIZE - offset, maxsize);

where 'nr' and 'offset' and both 'unsigned int', and PAGE_SIZE is
'unsigned long'.  As a result, the normal C type rules means that the
first argument to 'min()' ends up being 'unsigned long'.

In contrast, 'maxsize' is of type 'size_t'.

Now, 'size_t' and 'unsigned long' are always the same physical type in
the kernel, so you'd think this doesn't matter, and from an actual
arithmetic standpoint it doesn't.

But on 32-bit architectures 'size_t' is commonly 'unsigned int', even if
it could also be 'unsigned long'.  In that situation, both are unsigned
32-bit types, but they are not the *same* type.

And as a result 'min()' will complain about the distinct types (ignore
the "pointer types" part of the error message: that's an artifact of the
way we have made 'min()' check types for being the same):

  lib/iov_iter.c: In function 'iter_xarray_get_pages':
  include/linux/minmax.h:20:35: error: comparison of distinct pointer types lacks a cast [-Werror]
     20 |         (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
        |                                   ^~
  lib/iov_iter.c:1464:16: note: in expansion of macro 'min'
   1464 |         return min(nr * PAGE_SIZE - offset, maxsize);
        |                ^~~

This was not visible on 64-bit architectures (where we always define
'size_t' to be 'unsigned long').

Force these cases to use 'min_t(size_t, x, y)' to make the type explicit
and avoid the issue.

[ Nit-picky note: technically 'size_t' doesn't have to match 'unsigned
  long' arithmetically. We've certainly historically seen environments
  with 16-bit address spaces and 32-bit 'unsigned long'.

  Similarly, even in 64-bit modern environments, 'size_t' could be its
  own type distinct from 'unsigned long', even if it were arithmetically
  identical.

  So the above type commentary is only really descriptive of the kernel
  environment, not some kind of universal truth for the kinds of wild
  and crazy situations that are allowed by the C standard ]
Reported-by: default avatarSudip Mukherjee <sudipm.mukherjee@gmail.com>
Link: https://lore.kernel.org/all/YqRyL2sIqQNDfky2@debian/
Cc: Jeff Layton <jlayton@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1c27f1fc
    • Jason A. Donenfeld's avatar
      wireguard: selftests: use maximum cpu features and allow rng seeding · 17b0128a
      Jason A. Donenfeld authored 
      By forcing the maximum CPU that QEMU has available, we expose additional
capabilities, such as the RNDR instruction, which increases test
coverage. This then allows the CI to skip the fake seeding step in some
cases. Also enable STRICT_KERNEL_RWX to catch issues related to early
jump labels when the RNG is initialized at boot.
Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
      17b0128a
    • Kuan-Ying Lee's avatar
      scripts/gdb: change kernel config dumping method · 1f7a6cf6
      Kuan-Ying Lee authored 
      MAGIC_START("IKCFG_ST") and MAGIC_END("IKCFG_ED") are moved out
from the kernel_config_data variable.

Thus, we parse kernel_config_data directly instead of considering
offset of MAGIC_START and MAGIC_END.

Fixes: 13610aa9 ("kernel/configs: use .incbin directive to embed config_data.gz")
Signed-off-by: default avatarKuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      1f7a6cf6
    • Vincent Whitchurch's avatar
      um: virt-pci: set device ready in probe() · eacea844
      Vincent Whitchurch authored 
      Call virtio_device_ready() to make this driver work after commit
b4ec69d7e09 ("virtio: harden vring IRQ"), since the driver uses the
virtqueues in the probe function.  (The virtio core sets the device
ready when probe returns.)

Fixes: 8b4ec69d ("virtio: harden vring IRQ")
Fixes: 68f5d3f3 ("um: add PCI over virtio emulation driver")
Signed-off-by: default avatarVincent Whitchurch <vincent.whitchurch@axis.com>
Message-Id: <20220610151203.3492541-1-vincent.whitchurch@axis.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Tested-by: default avatarJohannes Berg <johannes@sipsolutions.net>
      eacea844
    • Linus Torvalds's avatar
      Merge tag 'nfsd-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux · 0885eacd
      Linus Torvalds authored 
      Pull nfsd fixes from Chuck Lever:
 "Notable changes:

   - There is now a backup maintainer for NFSD

  Notable fixes:

   - Prevent array overruns in svc_rdma_build_writes()

   - Prevent buffer overruns when encoding NFSv3 READDIR results

   - Fix a potential UAF in nfsd_file_put()"

* tag 'nfsd-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  SUNRPC: Remove pointer type casts from xdr_get_next_encode_buffer()
  SUNRPC: Clean up xdr_get_next_encode_buffer()
  SUNRPC: Clean up xdr_commit_encode()
  SUNRPC: Optimize xdr_reserve_space()
  SUNRPC: Fix the calculation of xdr->end in xdr_get_next_encode_buffer()
  SUNRPC: Trap RDMA segment overflows
  NFSD: Fix potential use-after-free in nfsd_file_put()
  MAINTAINERS: reciprocal co-maintainership for file locking and nfsd
      0885eacd
  9. 10 Jun, 2022 11 commits
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