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authorTrond Myklebust <Trond.Myklebust@netapp.com>2013-10-01 14:24:58 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-11-29 11:11:48 -0800
commit55fce163b8367ce78c163f0f63a8326ea266c09f (patch)
tree15561094734b54e20ccab089278a163e120e44fc /fs/nfs
parent5bc7e35d3470bf24c7640984bbfe20afd804afdb (diff)
downloadlinux-linaro-stable-55fce163b8367ce78c163f0f63a8326ea266c09f.tar.gz
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/nfs')
-rw-r--r--fs/nfs/nfs4proc.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index d7ba5616989c..3bafe0859999 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;
}