From: Peng Huang <shawn.p.huang@gmail.com>
To: Trond Myklebust <Trond.Myklebust@netapp.com>,
linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Peng Huang <shawn.p.huang@gmail.com>
Subject: [PATCH] nfs: check a crash in nfs_lookup_revalidate
Date: Wed, 11 May 2011 17:03:25 -0400 [thread overview]
Message-ID: <1305147805-5756-1-git-send-email-shawn.p.huang@gmail.com> (raw)
lookup_one_len() may call nfs_loopup_revalidate() with nd == NULL
indirectly, that causes the kernel crash.
RIP: 0010:[<ffffffffa0ba3b41>] [<ffffffffa0ba3b41>]
nfs_lookup_revalidate+0x21/0x4a0 [nfs]
RSP: 0018:ffff88018f00fae8 EFLAGS: 00010286
Call Trace:
[<ffffffff81164a17>] do_revalidate+0x17/0x60
[<ffffffff81164e9b>] __lookup_hash+0xcb/0x140
[<ffffffff811653c4>] lookup_one_len+0x94/0xe0
[<ffffffff81241ef1>] ecryptfs_lookup+0x91/0x1d0
[<ffffffff81164d85>] d_alloc_and_lookup+0x45/0x90
[<ffffffff8116f7b5>] ? d_lookup+0x35/0x60
[<ffffffff811669b2>] do_lookup+0x192/0x2d0
[<ffffffff811763be>] ? vfsmount_lock_local_unlock+0x1e/0x30
[<ffffffff8126d09c>] ? security_inode_permission+0x1c/0x30
[<ffffffff81167d67>] link_path_walk+0x597/0xae0
[<ffffffff8117638e>] ? vfsmount_lock_local_lock+0x1e/0x30
[<ffffffff81165905>] ? path_init_rcu+0xa5/0x210
[<ffffffff8116858b>] do_path_lookup+0x5b/0x140
[<ffffffff811692f7>] user_path_at+0x57/0xa0
[<ffffffff8159fd08>] ? do_page_fault+0x1e8/0x4e0
[<ffffffff8115eb86>] vfs_fstatat+0x46/0x80
[<ffffffff8116b990>] ? filldir+0x0/0xe0
[<ffffffff8115ec2e>] vfs_lstat+0x1e/0x20
[<ffffffff8115ec54>] sys_newlstat+0x24/0x50
[<ffffffff8159c995>] ? page_fault+0x25/0x30
[<ffffffff8100bfc2>] system_call_fastpath+0x16/0x1b
Signed-off-by: Peng Huang <shawn.p.huang@gmail.com>
---
fs/nfs/dir.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 2c3eb33..9452aa5 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1028,7 +1028,7 @@ static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
struct nfs_fattr *fattr = NULL;
int error;
- if (nd->flags & LOOKUP_RCU)
+ if (nd != NULL && nd->flags & LOOKUP_RCU)
return -ECHILD;
parent = dget_parent(dentry);
--
1.7.1
next reply other threads:[~2011-05-11 21:04 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-11 21:03 Peng Huang [this message]
2011-05-11 21:08 ` [PATCH] nfs: check a crash in nfs_lookup_revalidate Trond Myklebust
2011-05-11 21:35 ` Peng Huang
2011-05-11 22:08 ` Trond Myklebust
2011-05-11 22:17 ` Tyler Hicks
2011-05-11 22:33 ` Trond Myklebust
2011-05-11 23:07 ` Tyler Hicks
2011-05-13 10:32 ` Christoph Hellwig
2011-05-13 14:31 ` Peng Huang
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