1. 16 Aug, 2016 22 commits
    • Jan Kara's avatar
      ext4: fix deadlock during page writeback · 6e853b16
      Jan Kara authored
      commit 646caa9c upstream.
      
      Commit 06bd3c36 (ext4: fix data exposure after a crash) uncovered a
      deadlock in ext4_writepages() which was previously much harder to hit.
      After this commit xfstest generic/130 reproduces the deadlock on small
      filesystems.
      
      The problem happens when ext4_do_update_inode() sets LARGE_FILE feature
      and marks current inode handle as synchronous. That subsequently results
      in ext4_journal_stop() called from ext4_writepages() to block waiting for
      transaction commit while still holding page locks, reference to io_end,
      and some prepared bio in mpd structure each of which can possibly block
      transaction commit from completing and thus results in deadlock.
      
      Fix the problem by releasing page locks, io_end reference, and
      submitting prepared bio before calling ext4_journal_stop().
      
      [ Changed to defer the call to ext4_journal_stop() only if the handle
        is synchronous.  --tytso ]
      Reported-and-tested-by: default avatarEryu Guan <eguan@redhat.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6e853b16
    • Vegard Nossum's avatar
      ext4: check for extents that wrap around · be6acbd7
      Vegard Nossum authored
      commit f70749ca upstream.
      
      An extent with lblock = 4294967295 and len = 1 will pass the
      ext4_valid_extent() test:
      
      	ext4_lblk_t last = lblock + len - 1;
      
      	if (len == 0 || lblock > last)
      		return 0;
      
      since last = 4294967295 + 1 - 1 = 4294967295. This would later trigger
      the BUG_ON(es->es_lblk + es->es_len < es->es_lblk) in ext4_es_end().
      
      We can simplify it by removing the - 1 altogether and changing the test
      to use lblock + len <= lblock, since now if len = 0, then lblock + 0 ==
      lblock and it fails, and if len > 0 then lblock + len > lblock in order
      to pass (i.e. it doesn't overflow).
      
      Fixes: 5946d089 ("ext4: check for overlapping extents in ext4_valid_extent_entries()")
      Fixes: 2f974865 ("ext4: check for zero length extent explicitly")
      Cc: Eryu Guan <guaneryu@gmail.com>
      Signed-off-by: default avatarPhil Turnbull <phil.turnbull@oracle.com>
      Signed-off-by: default avatarVegard Nossum <vegard.nossum@oracle.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      be6acbd7
    • Herbert Xu's avatar
      crypto: scatterwalk - Fix test in scatterwalk_done · 29c8e059
      Herbert Xu authored
      commit 5f070e81 upstream.
      
      When there is more data to be processed, the current test in
      scatterwalk_done may prevent us from calling pagedone even when
      we should.
      
      In particular, if we're on an SG entry spanning multiple pages
      where the last page is not a full page, we will incorrectly skip
      calling pagedone on the second last page.
      
      This patch fixes this by adding a separate test for whether we've
      reached the end of a page.
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      29c8e059
    • Herbert Xu's avatar
      crypto: gcm - Filter out async ghash if necessary · 427810f9
      Herbert Xu authored
      commit b30bdfa8 upstream.
      
      As it is if you ask for a sync gcm you may actually end up with
      an async one because it does not filter out async implementations
      of ghash.
      
      This patch fixes this by adding the necessary filter when looking
      for ghash.
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      427810f9
    • Wei Fang's avatar
      fuse: fix wrong assignment of ->flags in fuse_send_init() · 4269a332
      Wei Fang authored
      commit 9446385f upstream.
      
      FUSE_HAS_IOCTL_DIR should be assigned to ->flags, it may be a typo.
      Signed-off-by: default avatarWei Fang <fangwei1@huawei.com>
      Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
      Fixes: 69fe05c9 ("fuse: add missing INIT flags")
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4269a332
    • Fabian Frederick's avatar
      sysv, ipc: fix security-layer leaking · cf0483ab
      Fabian Frederick authored
      commit 9b24fef9 upstream.
      
      Commit 53dad6d3 ("ipc: fix race with LSMs") updated ipc_rcu_putref()
      to receive rcu freeing function but used generic ipc_rcu_free() instead
      of msg_rcu_free() which does security cleaning.
      
      Running LTP msgsnd06 with kmemleak gives the following:
      
        cat /sys/kernel/debug/kmemleak
      
        unreferenced object 0xffff88003c0a11f8 (size 8):
          comm "msgsnd06", pid 1645, jiffies 4294672526 (age 6.549s)
          hex dump (first 8 bytes):
            1b 00 00 00 01 00 00 00                          ........
          backtrace:
            kmemleak_alloc+0x23/0x40
            kmem_cache_alloc_trace+0xe1/0x180
            selinux_msg_queue_alloc_security+0x3f/0xd0
            security_msg_queue_alloc+0x2e/0x40
            newque+0x4e/0x150
            ipcget+0x159/0x1b0
            SyS_msgget+0x39/0x40
            entry_SYSCALL_64_fastpath+0x13/0x8f
      
      Manfred Spraul suggested to fix sem.c as well and Davidlohr Bueso to
      only use ipc_rcu_free in case of security allocation failure in newary()
      
      Fixes: 53dad6d3 ("ipc: fix race with LSMs")
      Link: http://lkml.kernel.org/r/1470083552-22966-1-git-send-email-fabf@skynet.beSigned-off-by: default avatarFabian Frederick <fabf@skynet.be>
      Cc: Davidlohr Bueso <dbueso@suse.de>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      cf0483ab
    • Vegard Nossum's avatar
      block: fix use-after-free in seq file · 8cb3a415
      Vegard Nossum authored
      commit 77da1605 upstream.
      
      I got a KASAN report of use-after-free:
      
          ==================================================================
          BUG: KASAN: use-after-free in klist_iter_exit+0x61/0x70 at addr ffff8800b6581508
          Read of size 8 by task trinity-c1/315
          =============================================================================
          BUG kmalloc-32 (Not tainted): kasan: bad access detected
          -----------------------------------------------------------------------------
      
          Disabling lock debugging due to kernel taint
          INFO: Allocated in disk_seqf_start+0x66/0x110 age=144 cpu=1 pid=315
                  ___slab_alloc+0x4f1/0x520
                  __slab_alloc.isra.58+0x56/0x80
                  kmem_cache_alloc_trace+0x260/0x2a0
                  disk_seqf_start+0x66/0x110
                  traverse+0x176/0x860
                  seq_read+0x7e3/0x11a0
                  proc_reg_read+0xbc/0x180
                  do_loop_readv_writev+0x134/0x210
                  do_readv_writev+0x565/0x660
                  vfs_readv+0x67/0xa0
                  do_preadv+0x126/0x170
                  SyS_preadv+0xc/0x10
                  do_syscall_64+0x1a1/0x460
                  return_from_SYSCALL_64+0x0/0x6a
          INFO: Freed in disk_seqf_stop+0x42/0x50 age=160 cpu=1 pid=315
                  __slab_free+0x17a/0x2c0
                  kfree+0x20a/0x220
                  disk_seqf_stop+0x42/0x50
                  traverse+0x3b5/0x860
                  seq_read+0x7e3/0x11a0
                  proc_reg_read+0xbc/0x180
                  do_loop_readv_writev+0x134/0x210
                  do_readv_writev+0x565/0x660
                  vfs_readv+0x67/0xa0
                  do_preadv+0x126/0x170
                  SyS_preadv+0xc/0x10
                  do_syscall_64+0x1a1/0x460
                  return_from_SYSCALL_64+0x0/0x6a
      
          CPU: 1 PID: 315 Comm: trinity-c1 Tainted: G    B           4.7.0+ #62
          Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
           ffffea0002d96000 ffff880119b9f918 ffffffff81d6ce81 ffff88011a804480
           ffff8800b6581500 ffff880119b9f948 ffffffff8146c7bd ffff88011a804480
           ffffea0002d96000 ffff8800b6581500 fffffffffffffff4 ffff880119b9f970
          Call Trace:
           [<ffffffff81d6ce81>] dump_stack+0x65/0x84
           [<ffffffff8146c7bd>] print_trailer+0x10d/0x1a0
           [<ffffffff814704ff>] object_err+0x2f/0x40
           [<ffffffff814754d1>] kasan_report_error+0x221/0x520
           [<ffffffff8147590e>] __asan_report_load8_noabort+0x3e/0x40
           [<ffffffff83888161>] klist_iter_exit+0x61/0x70
           [<ffffffff82404389>] class_dev_iter_exit+0x9/0x10
           [<ffffffff81d2e8ea>] disk_seqf_stop+0x3a/0x50
           [<ffffffff8151f812>] seq_read+0x4b2/0x11a0
           [<ffffffff815f8fdc>] proc_reg_read+0xbc/0x180
           [<ffffffff814b24e4>] do_loop_readv_writev+0x134/0x210
           [<ffffffff814b4c45>] do_readv_writev+0x565/0x660
           [<ffffffff814b8a17>] vfs_readv+0x67/0xa0
           [<ffffffff814b8de6>] do_preadv+0x126/0x170
           [<ffffffff814b92ec>] SyS_preadv+0xc/0x10
      
      This problem can occur in the following situation:
      
      open()
       - pread()
          - .seq_start()
             - iter = kmalloc() // succeeds
             - seqf->private = iter
          - .seq_stop()
             - kfree(seqf->private)
       - pread()
          - .seq_start()
             - iter = kmalloc() // fails
          - .seq_stop()
             - class_dev_iter_exit(seqf->private) // boom! old pointer
      
      As the comment in disk_seqf_stop() says, stop is called even if start
      failed, so we need to reinitialise the private pointer to NULL when seq
      iteration stops.
      
      An alternative would be to set the private pointer to NULL when the
      kmalloc() in disk_seqf_start() fails.
      Signed-off-by: default avatarVegard Nossum <vegard.nossum@oracle.com>
      Acked-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8cb3a415
    • Jason Gunthorpe's avatar
      IB/security: Restrict use of the write() interface · c96c87e1
      Jason Gunthorpe authored
      commit e6bd18f5 upstream.
      
      The drivers/infiniband stack uses write() as a replacement for
      bi-directional ioctl().  This is not safe. There are ways to
      trigger write calls that result in the return structure that
      is normally written to user space being shunted off to user
      specified kernel memory instead.
      
      For the immediate repair, detect and deny suspicious accesses to
      the write API.
      
      For long term, update the user space libraries and the kernel API
      to something that doesn't present the same security vulnerabilities
      (likely a structured ioctl() interface).
      
      The impacted uAPI interfaces are generally only available if
      hardware from drivers/infiniband is installed in the system.
      Reported-by: default avatarJann Horn <jann@thejh.net>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarJason Gunthorpe <jgunthorpe@obsidianresearch.com>
      [ Expanded check to all known write() entry points ]
      Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
      [ Expanded to include removed ipath driver, and dropped non-existent
        hfi1 driver ]
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c96c87e1
    • James Bottomley's avatar
      scsi_lib: correctly retry failed zero length REQ_TYPE_FS commands · 4b3aa865
      James Bottomley authored
      commit a621bac3 upstream.
      
      When SCSI was written, all commands coming from the filesystem
      (REQ_TYPE_FS commands) had data.  This meant that our signal for needing
      to complete the command was the number of bytes completed being equal to
      the number of bytes in the request.  Unfortunately, with the advent of
      flush barriers, we can now get zero length REQ_TYPE_FS commands, which
      confuse this logic because they satisfy the condition every time.  This
      means they never get retried even for retryable conditions, like UNIT
      ATTENTION because we complete them early assuming they're done.  Fix
      this by special casing the early completion condition to recognise zero
      length commands with errors and let them drop through to the retry code.
      Reported-by: default avatarSebastian Parschauer <s.parschauer@gmx.de>
      Signed-off-by: default avatarJames E.J. Bottomley <jejb@linux.vnet.ibm.com>
      Tested-by: default avatarJack Wang <jinpu.wang@profitbricks.com>
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      [ jwang: backport from upstream 4.7 to fix scsi resize issue ]
      Signed-off-by: default avatarJack Wang <jinpu.wang@profitbricks.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4b3aa865
    • Christoph Hellwig's avatar
      scsi: remove scsi_end_request · 0e97a8f3
      Christoph Hellwig authored
      commit bc85dc50 upstream.
      
      By folding scsi_end_request into its only caller we can significantly clean
      up the completion logic.  We can use simple goto labels now to only have
      a single place to finish or requeue command there instead of the previous
      convoluted logic.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      Reviewed-by: default avatarMike Christie <michaelc@cs.wisc.edu>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      [jwang: backport to 3.12]
      Signed-off-by: default avatarJack Wang <jinpu.wang@profitbricks.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0e97a8f3
    • Theodore Ts'o's avatar
      random: strengthen input validation for RNDADDTOENTCNT · 25bc549d
      Theodore Ts'o authored
      commit 86a574de upstream.
      
      Don't allow RNDADDTOENTCNT or RNDADDENTROPY to accept a negative
      entropy value.  It doesn't make any sense to subtract from the entropy
      counter, and it can trigger a warning:
      
      random: negative entropy/overflow: pool input count -40000
      ------------[ cut here ]------------
      WARNING: CPU: 3 PID: 6828 at drivers/char/random.c:670[<      none
       >] credit_entropy_bits+0x21e/0xad0 drivers/char/random.c:670
      Modules linked in:
      CPU: 3 PID: 6828 Comm: a.out Not tainted 4.7.0-rc4+ #4
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
       ffffffff880b58e0 ffff88005dd9fcb0 ffffffff82cc838f ffffffff87158b40
       fffffbfff1016b1c 0000000000000000 0000000000000000 ffffffff87158b40
       ffffffff83283dae 0000000000000009 ffff88005dd9fcf8 ffffffff8136d27f
      Call Trace:
       [<     inline     >] __dump_stack lib/dump_stack.c:15
       [<ffffffff82cc838f>] dump_stack+0x12e/0x18f lib/dump_stack.c:51
       [<ffffffff8136d27f>] __warn+0x19f/0x1e0 kernel/panic.c:516
       [<ffffffff8136d48c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:551
       [<ffffffff83283dae>] credit_entropy_bits+0x21e/0xad0 drivers/char/random.c:670
       [<     inline     >] credit_entropy_bits_safe drivers/char/random.c:734
       [<ffffffff8328785d>] random_ioctl+0x21d/0x250 drivers/char/random.c:1546
       [<     inline     >] vfs_ioctl fs/ioctl.c:43
       [<ffffffff8185316c>] do_vfs_ioctl+0x18c/0xff0 fs/ioctl.c:674
       [<     inline     >] SYSC_ioctl fs/ioctl.c:689
       [<ffffffff8185405f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:680
       [<ffffffff86a995c0>] entry_SYSCALL_64_fastpath+0x23/0xc1
      arch/x86/entry/entry_64.S:207
      ---[ end trace 5d4902b2ba842f1f ]---
      
      This was triggered using the test program:
      
      // autogenerated by syzkaller (http://github.com/google/syzkaller)
      
      int main() {
              int fd = open("/dev/random", O_RDWR);
              int val = -5000;
              ioctl(fd, RNDADDTOENTCNT, &val);
              return 0;
      }
      
      It's harmless in that (a) only root can trigger it, and (b) after
      complaining the code never does let the entropy count go negative, but
      it's better to simply not allow this userspace from passing in a
      negative entropy value altogether.
      
      Google-Bug-Id: #29575089
      Reported-By: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      25bc549d
    • John Johansen's avatar
    • David Howells's avatar
      KEYS: 64-bit MIPS needs to use compat_sys_keyctl for 32-bit userspace · 6fc918b2
      David Howells authored
      commit 20f06ed9 upstream.
      
      MIPS64 needs to use compat_sys_keyctl for 32-bit userspace rather than
      calling sys_keyctl.  The latter will work in a lot of cases, thereby hiding
      the issue.
      Reported-by: default avatarStephan Mueller <smueller@chronox.de>
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Cc: linux-mips@linux-mips.org
      Cc: linux-kernel@vger.kernel.org
      Cc: linux-security-module@vger.kernel.org
      Cc: keyrings@vger.kernel.org
      Patchwork: https://patchwork.linux-mips.org/patch/13832/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6fc918b2
    • Dave Weinstein's avatar
      arm: oabi compat: add missing access checks · e380a271
      Dave Weinstein authored
      commit 7de24996 upstream.
      
      Add access checks to sys_oabi_epoll_wait() and sys_oabi_semtimedop().
      This fixes CVE-2016-3857, a local privilege escalation under
      CONFIG_OABI_COMPAT.
      Reported-by: default avatarChiachih Wu <wuchiachih@gmail.com>
      Reviewed-by: default avatarKees Cook <keescook@chromium.org>
      Reviewed-by: default avatarNicolas Pitre <nico@linaro.org>
      Signed-off-by: default avatarDave Weinstein <olorin@google.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e380a271
    • Greg Kroah-Hartman's avatar
      USB: fix up incorrect quirk · 68c20ee3
      Greg Kroah-Hartman authored
      Ben Hutchings reported that commit ddbe1fca ("USB: Add device quirk
      for ASUS T100 Base Station keyboard") was incorrectly ported.
      
      This patch fixes up the quirk by putting it in the correct table.
      Reported-by: default avatarBen Hutchings <ben@decadent.org.uk>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      68c20ee3
    • Bjørn Mork's avatar
      cdc_ncm: do not call usbnet_link_change from cdc_ncm_bind · 0c17e108
      Bjørn Mork authored
      commit 4d06dd53 upstream.
      
      usbnet_link_change will call schedule_work and should be
      avoided if bind is failing. Otherwise we will end up with
      scheduled work referring to a netdev which has gone away.
      
      Instead of making the call conditional, we can just defer
      it to usbnet_probe, using the driver_info flag made for
      this purpose.
      
      Fixes: 8a34b0ae ("usbnet: cdc_ncm: apply usbnet_link_change")
      Reported-by: default avatarAndrey Konovalov <andreyknvl@gmail.com>
      Suggested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarBjørn Mork <bjorn@mork.no>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      [ciwillia@brocade.com: backported to 3.14: adjusted context]
      Signed-off-by: default avatarCharles (Chas) Williams <ciwillia@brocade.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0c17e108
    • Andy Lutomirski's avatar
      x86/mm: Improve switch_mm() barrier comments · 46fdf98a
      Andy Lutomirski authored
      commit 4eaffdd5 upstream.
      
      My previous comments were still a bit confusing and there was a
      typo. Fix it up.
      Reported-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: stable@vger.kernel.org
      Fixes: 71b3c126 ("x86/mm: Add barriers and document switch_mm()-vs-flush synchronization")
      Link: http://lkml.kernel.org/r/0a0b43cdcdd241c5faaaecfbcc91a155ddedc9a1.1452631609.git.luto@kernel.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      46fdf98a
    • Karl Heiss's avatar
      sctp: Prevent soft lockup when sctp_accept() is called during a timeout event · a4377c6e
      Karl Heiss authored
      commit 635682a1 upstream.
      
      A case can occur when sctp_accept() is called by the user during
      a heartbeat timeout event after the 4-way handshake.  Since
      sctp_assoc_migrate() changes both assoc->base.sk and assoc->ep, the
      bh_sock_lock in sctp_generate_heartbeat_event() will be taken with
      the listening socket but released with the new association socket.
      The result is a deadlock on any future attempts to take the listening
      socket lock.
      
      Note that this race can occur with other SCTP timeouts that take
      the bh_lock_sock() in the event sctp_accept() is called.
      
       BUG: soft lockup - CPU#9 stuck for 67s! [swapper:0]
       ...
       RIP: 0010:[<ffffffff8152d48e>]  [<ffffffff8152d48e>] _spin_lock+0x1e/0x30
       RSP: 0018:ffff880028323b20  EFLAGS: 00000206
       RAX: 0000000000000002 RBX: ffff880028323b20 RCX: 0000000000000000
       RDX: 0000000000000000 RSI: ffff880028323be0 RDI: ffff8804632c4b48
       RBP: ffffffff8100bb93 R08: 0000000000000000 R09: 0000000000000000
       R10: ffff880610662280 R11: 0000000000000100 R12: ffff880028323aa0
       R13: ffff8804383c3880 R14: ffff880028323a90 R15: ffffffff81534225
       FS:  0000000000000000(0000) GS:ffff880028320000(0000) knlGS:0000000000000000
       CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
       CR2: 00000000006df528 CR3: 0000000001a85000 CR4: 00000000000006e0
       DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
       DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
       Process swapper (pid: 0, threadinfo ffff880616b70000, task ffff880616b6cab0)
       Stack:
       ffff880028323c40 ffffffffa01c2582 ffff880614cfb020 0000000000000000
       <d> 0100000000000000 00000014383a6c44 ffff8804383c3880 ffff880614e93c00
       <d> ffff880614e93c00 0000000000000000 ffff8804632c4b00 ffff8804383c38b8
       Call Trace:
       <IRQ>
       [<ffffffffa01c2582>] ? sctp_rcv+0x492/0xa10 [sctp]
       [<ffffffff8148c559>] ? nf_iterate+0x69/0xb0
       [<ffffffff814974a0>] ? ip_local_deliver_finish+0x0/0x2d0
       [<ffffffff8148c716>] ? nf_hook_slow+0x76/0x120
       [<ffffffff814974a0>] ? ip_local_deliver_finish+0x0/0x2d0
       [<ffffffff8149757d>] ? ip_local_deliver_finish+0xdd/0x2d0
       [<ffffffff81497808>] ? ip_local_deliver+0x98/0xa0
       [<ffffffff81496ccd>] ? ip_rcv_finish+0x12d/0x440
       [<ffffffff81497255>] ? ip_rcv+0x275/0x350
       [<ffffffff8145cfeb>] ? __netif_receive_skb+0x4ab/0x750
       ...
      
      With lockdep debugging:
      
       =====================================
       [ BUG: bad unlock balance detected! ]
       -------------------------------------
       CslRx/12087 is trying to release lock (slock-AF_INET) at:
       [<ffffffffa01bcae0>] sctp_generate_timeout_event+0x40/0xe0 [sctp]
       but there are no more locks to release!
      
       other info that might help us debug this:
       2 locks held by CslRx/12087:
       #0:  (&asoc->timers[i]){+.-...}, at: [<ffffffff8108ce1f>] run_timer_softirq+0x16f/0x3e0
       #1:  (slock-AF_INET){+.-...}, at: [<ffffffffa01bcac3>] sctp_generate_timeout_event+0x23/0xe0 [sctp]
      
      Ensure the socket taken is also the same one that is released by
      saving a copy of the socket before entering the timeout event
      critical section.
      Signed-off-by: default avatarKarl Heiss <kheiss@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Cc: Ben Hutchings <ben@decadent.org.uk>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      (cherry picked from commit 013dd9e0)
      Signed-off-by: default avatarChas Williams <3chas3@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a4377c6e
    • Andy Lutomirski's avatar
      x86/mm: Add barriers and document switch_mm()-vs-flush synchronization · 1b8542cd
      Andy Lutomirski authored
      commit 71b3c126 upstream.
      
      When switch_mm() activates a new PGD, it also sets a bit that
      tells other CPUs that the PGD is in use so that TLB flush IPIs
      will be sent.  In order for that to work correctly, the bit
      needs to be visible prior to loading the PGD and therefore
      starting to fill the local TLB.
      
      Document all the barriers that make this work correctly and add
      a couple that were missing.
      Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-mm@kvack.org
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      [ luis: backported to 3.16:
        - dropped N/A comment in flush_tlb_mm_range()
        - adjusted context ]
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      [ciwillia@brocade.com: backported to 3.14: adjusted context]
      Signed-off-by: default avatarCharles (Chas) Williams <ciwillia@brocade.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1b8542cd
    • Tejun Heo's avatar
      printk: do cond_resched() between lines while outputting to consoles · 7c7b4fe1
      Tejun Heo authored
      commit 8d91f8b1 upstream.
      
      @console_may_schedule tracks whether console_sem was acquired through
      lock or trylock.  If the former, we're inside a sleepable context and
      console_conditional_schedule() performs cond_resched().  This allows
      console drivers which use console_lock for synchronization to yield
      while performing time-consuming operations such as scrolling.
      
      However, the actual console outputting is performed while holding
      irq-safe logbuf_lock, so console_unlock() clears @console_may_schedule
      before starting outputting lines.  Also, only a few drivers call
      console_conditional_schedule() to begin with.  This means that when a
      lot of lines need to be output by console_unlock(), for example on a
      console registration, the task doing console_unlock() may not yield for
      a long time on a non-preemptible kernel.
      
      If this happens with a slow console devices, for example a serial
      console, the outputting task may occupy the cpu for a very long time.
      Long enough to trigger softlockup and/or RCU stall warnings, which in
      turn pile more messages, sometimes enough to trigger the next cycle of
      warnings incapacitating the system.
      
      Fix it by making console_unlock() insert cond_resched() between lines if
      @console_may_schedule.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Reported-by: default avatarCalvin Owens <calvinowens@fb.com>
      Acked-by: default avatarJan Kara <jack@suse.com>
      Cc: Dave Jones <davej@codemonkey.org.uk>
      Cc: Kyle McMartin <kyle@kernel.org>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      [ciwillia@brocade.com: adjust context for 3.14.y]
      Signed-off-by: default avatarChas Williams <ciwillia@brocade.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7c7b4fe1
    • Hugh Dickins's avatar
      mm: migrate dirty page without clear_page_dirty_for_io etc · 53a35fd3
      Hugh Dickins authored
      commit 42cb14b1 upstream.
      
      clear_page_dirty_for_io() has accumulated writeback and memcg subtleties
      since v2.6.16 first introduced page migration; and the set_page_dirty()
      which completed its migration of PageDirty, later had to be moderated to
      __set_page_dirty_nobuffers(); then PageSwapBacked had to skip that too.
      
      No actual problems seen with this procedure recently, but if you look into
      what the clear_page_dirty_for_io(page)+set_page_dirty(newpage) is actually
      achieving, it turns out to be nothing more than moving the PageDirty flag,
      and its NR_FILE_DIRTY stat from one zone to another.
      
      It would be good to avoid a pile of irrelevant decrementations and
      incrementations, and improper event counting, and unnecessary descent of
      the radix_tree under tree_lock (to set the PAGECACHE_TAG_DIRTY which
      radix_tree_replace_slot() left in place anyway).
      
      Do the NR_FILE_DIRTY movement, like the other stats movements, while
      interrupts still disabled in migrate_page_move_mapping(); and don't even
      bother if the zone is the same.  Do the PageDirty movement there under
      tree_lock too, where old page is frozen and newpage not yet visible:
      bearing in mind that as soon as newpage becomes visible in radix_tree, an
      un-page-locked set_page_dirty() might interfere (or perhaps that's just
      not possible: anything doing so should already hold an additional
      reference to the old page, preventing its migration; but play safe).
      
      But we do still need to transfer PageDirty in migrate_page_copy(), for
      those who don't go the mapping route through migrate_page_move_mapping().
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Sasha Levin <sasha.levin@oracle.com>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      [ciwillia@brocade.com: backported to 3.14: adjusted context]
      Signed-off-by: default avatarCharles (Chas) Williams <ciwillia@brocade.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      53a35fd3
    • Alan Stern's avatar
      USB: fix invalid memory access in hub_activate() · 627c25d0
      Alan Stern authored
      commit e50293ef upstream.
      
      Commit 8520f380 ("USB: change hub initialization sleeps to
      delayed_work") changed the hub_activate() routine to make part of it
      run in a workqueue.  However, the commit failed to take a reference to
      the usb_hub structure or to lock the hub interface while doing so.  As
      a result, if a hub is plugged in and quickly unplugged before the work
      routine can run, the routine will try to access memory that has been
      deallocated.  Or, if the hub is unplugged while the routine is
      running, the memory may be deallocated while it is in active use.
      
      This patch fixes the problem by taking a reference to the usb_hub at
      the start of hub_activate() and releasing it at the end (when the work
      is finished), and by locking the hub interface while the work routine
      is running.  It also adds a check at the start of the routine to see
      if the hub has already been disconnected, in which nothing should be
      done.
      Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
      Reported-by: default avatarAlexandru Cornea <alexandru.cornea@intel.com>
      Tested-by: default avatarAlexandru Cornea <alexandru.cornea@intel.com>
      Fixes: 8520f380 ("USB: change hub initialization sleeps to delayed_work")
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      [ luis: backported to 3.16:
        - Added forward declaration of hub_release() which mainline had with commit
          32a69589 ("usb: hub: convert khubd into workqueue") ]
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      Signed-off-by: default avatarCharles (Chas) Williams <ciwillia@brocade.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      627c25d0
  2. 10 Aug, 2016 18 commits