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  1. 22 Jan, 2014 31 commits
  3. 13 Jan, 2014 4 commits
  5. 12 Jan, 2014 4 commits
    • Linus Torvalds's avatar
      Linux 3.13-rc8 · 7e22e911
      Linus Torvalds authored
      7e22e911
    • Steven Rostedt's avatar
      SELinux: Fix possible NULL pointer dereference in selinux_inode_permission() · 3dc91d43
      Steven Rostedt authored 
      While running stress tests on adding and deleting ftrace instances I hit
this bug:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
  IP: selinux_inode_permission+0x85/0x160
  PGD 63681067 PUD 7ddbe067 PMD 0
  Oops: 0000 [#1] PREEMPT
  CPU: 0 PID: 5634 Comm: ftrace-test-mki Not tainted 3.13.0-rc4-test-00033-gd2a6dde-dirty #20
  Hardware name:                  /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006
  task: ffff880078375800 ti: ffff88007ddb0000 task.ti: ffff88007ddb0000
  RIP: 0010:[<ffffffff812d8bc5>]  [<ffffffff812d8bc5>] selinux_inode_permission+0x85/0x160
  RSP: 0018:ffff88007ddb1c48  EFLAGS: 00010246
  RAX: 0000000000000000 RBX: 0000000000800000 RCX: ffff88006dd43840
  RDX: 0000000000000001 RSI: 0000000000000081 RDI: ffff88006ee46000
  RBP: ffff88007ddb1c88 R08: 0000000000000000 R09: ffff88007ddb1c54
  R10: 6e6576652f6f6f66 R11: 0000000000000003 R12: 0000000000000000
  R13: 0000000000000081 R14: ffff88006ee46000 R15: 0000000000000000
  FS:  00007f217b5b6700(0000) GS:ffffffff81e21000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033^M
  CR2: 0000000000000020 CR3: 000000006a0fe000 CR4: 00000000000007f0
  Call Trace:
    security_inode_permission+0x1c/0x30
    __inode_permission+0x41/0xa0
    inode_permission+0x18/0x50
    link_path_walk+0x66/0x920
    path_openat+0xa6/0x6c0
    do_filp_open+0x43/0xa0
    do_sys_open+0x146/0x240
    SyS_open+0x1e/0x20
    system_call_fastpath+0x16/0x1b
  Code: 84 a1 00 00 00 81 e3 00 20 00 00 89 d8 83 c8 02 40 f6 c6 04 0f 45 d8 40 f6 c6 08 74 71 80 cf 02 49 8b 46 38 4c 8d 4d cc 45 31 c0 <0f> b7 50 20 8b 70 1c 48 8b 41 70 89 d9 8b 78 04 e8 36 cf ff ff
  RIP  selinux_inode_permission+0x85/0x160
  CR2: 0000000000000020

Investigating, I found that the inode->i_security was NULL, and the
dereference of it caused the oops.

in selinux_inode_permission():

	isec = inode->i_security;

	rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd);

Note, the crash came from stressing the deletion and reading of debugfs
files.  I was not able to recreate this via normal files.  But I'm not
sure they are safe.  It may just be that the race window is much harder
to hit.

What seems to have happened (and what I have traced), is the file is
being opened at the same time the file or directory is being deleted.
As the dentry and inode locks are not held during the path walk, nor is
the inodes ref counts being incremented, there is nothing saving these
structures from being discarded except for an rcu_read_lock().

The rcu_read_lock() protects against freeing of the inode, but it does
not protect freeing of the inode_security_struct.  Now if the freeing of
the i_security happens with a call_rcu(), and the i_security field of
the inode is not changed (it gets freed as the inode gets freed) then
there will be no issue here.  (Linus Torvalds suggested not setting the
field to NULL such that we do not need to check if it is NULL in the
permission check).

Note, this is a hack, but it fixes the problem at hand.  A real fix is
to restructure the destroy_inode() to call all the destructor handlers
from the RCU callback.  But that is a major job to do, and requires a
lot of work.  For now, we just band-aid this bug with this fix (it
works), and work on a more maintainable solution in the future.

Link: http://lkml.kernel.org/r/20140109101932.0508dec7@gandalf.local.home
Link: http://lkml.kernel.org/r/20140109182756.17abaaa8@gandalf.local.home

Cc: stable@vger.kernel.org
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3dc91d43
    • Hugh Dickins's avatar
      thp: fix copy_page_rep GPF by testing is_huge_zero_pmd once only · eecc1e42
      Hugh Dickins authored 
      We see General Protection Fault on RSI in copy_page_rep: that RSI is
what you get from a NULL struct page pointer.

  RIP: 0010:[<ffffffff81154955>]  [<ffffffff81154955>] copy_page_rep+0x5/0x10
  RSP: 0000:ffff880136e15c00  EFLAGS: 00010286
  RAX: ffff880000000000 RBX: ffff880136e14000 RCX: 0000000000000200
  RDX: 6db6db6db6db6db7 RSI: db73880000000000 RDI: ffff880dd0c00000
  RBP: ffff880136e15c18 R08: 0000000000000200 R09: 000000000005987c
  R10: 000000000005987c R11: 0000000000000200 R12: 0000000000000001
  R13: ffffea00305aa000 R14: 0000000000000000 R15: 0000000000000000
  FS:  00007f195752f700(0000) GS:ffff880c7fc20000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000093010000 CR3: 00000001458e1000 CR4: 00000000000027e0
  Call Trace:
    copy_user_huge_page+0x93/0xab
    do_huge_pmd_wp_page+0x710/0x815
    handle_mm_fault+0x15d8/0x1d70
    __do_page_fault+0x14d/0x840
    do_page_fault+0x2f/0x90
    page_fault+0x22/0x30

do_huge_pmd_wp_page() tests is_huge_zero_pmd(orig_pmd) four times: but
since shrink_huge_zero_page() can free the huge_zero_page, and we have
no hold of our own on it here (except where the fourth test holds
page_table_lock and has checked pmd_same), it's possible for it to
answer yes the first time, but no to the second or third test.  Change
all those last three to tests for NULL page.

(Note: this is not the same issue as trinity's DEBUG_PAGEALLOC BUG
in copy_page_rep with RSI: ffff88009c422000, reported by Sasha Levin
in https://lkml.org/lkml/2013/3/29/103.  I believe that one is due
to the source page being split, and a tail page freed, while copy
is in progress; and not a problem without DEBUG_PAGEALLOC, since
the pmd_same check will prevent a miscopy from being made visible.)

Fixes: 97ae1749 ("thp: implement refcounting for huge zero page")
Signed-off-by: default avatarHugh Dickins <hughd@google.com>
Cc: stable@vger.kernel.org # v3.10 v3.11 v3.12
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      eecc1e42
    • Ming Lei's avatar
      block: null_blk: fix queue leak inside removing device · 518d00b7
      Ming Lei authored 
      When queue_mode is NULL_Q_MQ and null_blk is being removed,
blk_cleanup_queue() isn't called to cleanup queue, so the queue
allocated won't be freed.

This patch calls blk_cleanup_queue() for MQ to drain all pending
requests first and release the reference counter of queue kobject, then
blk_mq_free_queue() will be called in queue kobject's release handler
when queue kobject's reference counter drops to zero.
Signed-off-by: default avatarMing Lei <tom.leiming@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      518d00b7
  7. 10 Jan, 2014 1 commit
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · 228fdc08
      Linus Torvalds authored 
      Pull networking fixes from David Miller:
 "Famouse last words: "final pull request" :-)

  I'm sending this because Jason Wang's fixes are pretty important

   1) Add missing per-cpu stats initialization to ip6_vti.  Otherwise
      lockdep spits out a call trace.  From Li RongQing.

   2) Fix NULL oops in wireless hwsim, from Javier Lopez

   3) TIPC deferred packet queue unlink must NULL out skb->next to avoid
      crashes.  From Erik Hugne

   4) Fix access to uninitialized buffer in nf_nat netfilter code, from
      Daniel Borkmann

   5) Fix lifetime of ipv6 loopback and SIT tunnel addresses, otherwise
      they basically timeout immediately.  From Hannes Frederic Sowa

   6) Fix DMA unmapping of TSO packets in bnx2x driver, from Michal
      Schmidt

   7) Do not allow L2 forwarding offload via macvtap device, the way
      things are now it will not end up being forwaded at all.  From
      Jason Wang

   8) Fix transmit queue selection via ndo_dfwd_start_xmit(), fixing
      things like applying NETIF_F_LLTX to the wrong device (!!) and
      eliding the proper transmit watchdog handling

   9) qlcnic driver was not updating tx statistics at all, from Manish
      Chopra"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  qlcnic: Fix ethtool statistics length calculation
  qlcnic: Fix bug in TX statistics
  net: core: explicitly select a txq before doing l2 forwarding
  macvlan: forbid L2 fowarding offload for macvtap
  bnx2x: fix DMA unmapping of TSO split BDs
  ipv6: add link-local, sit and loopback address with INFINITY_LIFE_TIME
  bnx2x: prevent WARN during driver unload
  tipc: correctly unlink packets from deferred packet queue
  ipv6: pcpu_tstats.syncp should be initialised in ip6_vti.c
  netfilter: only warn once on wrong seqadj usage
  netfilter: nf_nat: fix access to uninitialized buffer in IRC NAT helper
  NFC: Fix target mode p2p link establishment
  iwlwifi: add new devices for 7265 series
  mac80211: move "bufferable MMPDU" check to fix AP mode scan
  mac80211_hwsim: Fix NULL pointer dereference
      228fdc08
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