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  1. 21 Oct, 2009 2 commits
    • Yinghai Lu's avatar
      nfs: Fix nfs_parse_mount_options() kfree() leak · 4223a4a1
      Yinghai Lu authored 
      Fix a (small) memory leak in one of the error paths of the NFS mount
options parsing code.

Regression introduced in 2.6.30 by commit a67d18f8 (NFS: load the
rpc/rdma transport module automatically).
Reported-by: default avatarYinghai Lu <yinghai@kernel.org>
Reported-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4223a4a1
    • Earl Chew's avatar
      fs: pipe.c null pointer dereference · ad396024
      Earl Chew authored 
      This patch fixes a null pointer exception in pipe_rdwr_open() which
generates the stack trace:

> Unable to handle kernel NULL pointer dereference at 0000000000000028 RIP:
>  [<ffffffff802899a5>] pipe_rdwr_open+0x35/0x70
>  [<ffffffff8028125c>] __dentry_open+0x13c/0x230
>  [<ffffffff8028143d>] do_filp_open+0x2d/0x40
>  [<ffffffff802814aa>] do_sys_open+0x5a/0x100
>  [<ffffffff8021faf3>] sysenter_do_call+0x1b/0x67

The failure mode is triggered by an attempt to open an anonymous
pipe via /proc/pid/fd/* as exemplified by this script:

=============================================================
while : ; do
   { echo y ; sleep 1 ; } | { while read ; do echo z$REPLY; done ; } &
   PID=$!
   OUT=$(ps -efl | grep 'sleep 1' | grep -v grep |
        { read PID REST ; echo $PID; } )
   OUT="${OUT%% *}"
   DELAY=$((RANDOM * 1000 / 32768))
   usleep $((DELAY * 1000 + RANDOM % 1000 ))
   echo n > /proc/$OUT/fd/1                 # Trigger defect
done
=============================================================

Note that the failure window is quite small and I could only
reliably reproduce the defect by inserting a small delay
in pipe_rdwr_open(). For example:

 static int
 pipe_rdwr_open(struct inode *inode, struct file *filp)
 {
       msleep(100);
       mutex_lock(&inode->i_mutex);

Although the defect was observed in pipe_rdwr_open(), I think it
makes sense to replicate the change through all the pipe_*_open()
functions.

The core of the change is to verify that inode->i_pipe has not
been released before attempting to manipulate it. If inode->i_pipe
is no longer present, return ENOENT to indicate so.

The comment about potentially using atomic_t for i_pipe->readers
and i_pipe->writers has also been removed because it is no longer
relevant in this context. The inode->i_mutex lock must be used so
that inode->i_pipe can be dealt with correctly.
Signed-off-by: default avatarEarl Chew <earl_chew@agilent.com>
Cc: stable@kernel.org
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ad396024
  3. 16 Oct, 2009 12 commits
  5. 15 Oct, 2009 23 commits
  7. 14 Oct, 2009 3 commits
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