diff options
| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2013-10-01 14:24:58 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-11-29 11:11:48 -0800 |
| commit | 55fce163b8367ce78c163f0f63a8326ea266c09f (patch) | |
| tree | 15561094734b54e20ccab089278a163e120e44fc /fs | |
| parent | 5bc7e35d3470bf24c7640984bbfe20afd804afdb (diff) | |
NFSv4: Fix a use-after-free situation in _nfs4_proc_getlk()
commit a6f951ddbdfb7bd87d31a44f61abe202ed6ce57f upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -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 d7ba5616989..3bafe085999 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -4572,6 +4572,7 @@ 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; } |