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| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2013-10-01 14:24:58 -0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2013-10-01 18:21:28 -0400 |
| commit | a6f951ddbdfb7bd87d31a44f61abe202ed6ce57f (patch) | |
| tree | 31d73a4db7641204336ae0abbd548e9c19eedd49 | |
| parent | f927318840745095cc7003f1564ca4b87655745d (diff) | |
| download | linux-a6f951ddbdfb7bd87d31a44f61abe202ed6ce57f.tar.bz2 | |
NFSv4: Fix a use-after-free situation in _nfs4_proc_getlk()
In nfs4_proc_getlk(), when some error causes a retry of the call to
_nfs4_proc_getlk(), we can end up with Oopses of the form
BUG: unable to handle kernel NULL pointer dereference at 0000000000000134
IP: [<ffffffff8165270e>] _raw_spin_lock+0xe/0x30
<snip>
Call Trace:
[<ffffffff812f287d>] _atomic_dec_and_lock+0x4d/0x70
[<ffffffffa053c4f2>] nfs4_put_lock_state+0x32/0xb0 [nfsv4]
[<ffffffffa053c585>] nfs4_fl_release_lock+0x15/0x20 [nfsv4]
[<ffffffffa0522c06>] _nfs4_proc_getlk.isra.40+0x146/0x170 [nfsv4]
[<ffffffffa052ad99>] nfs4_proc_lock+0x399/0x5a0 [nfsv4]
The problem is that we don't clear the request->fl_ops after the first
try and so when we retry, nfs4_set_lock_state() exits early without
setting the lock stateid.
Regression introduced by commit 70cc6487a4e08b8698c0e2ec935fb48d10490162
(locks: make ->lock release private data before returning in GETLK case)
Reported-by: Weston Andros Adamson <dros@netapp.com>
Reported-by: Jorge Mora <mora@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: <stable@vger.kernel.org> #2.6.22+
| -rw-r--r-- | fs/nfs/nfs4proc.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index d53d6785cba2..d2b4845ecb4d 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -5106,6 +5106,7 @@ static int _nfs4_proc_getlk(struct nfs4_state *state, int cmd, struct file_lock status = 0; } request->fl_ops->fl_release_private(request); + request->fl_ops = NULL; out: return status; } |