diff options
| author | Mike Snitzer <snitzer@gmail.com> | 2008-04-02 13:04:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-02 15:28:19 -0700 |
| commit | ffc41cf8dbb1b895a87daf47d0e5bf6dfbfcab4c (patch) | |
| tree | 465f41f6c4e0e63c58a94c893d0b4ec5c5e7a10d | |
| parent | f2b2ea692ec01768c77a4f532dcd060316460122 (diff) | |
| download | lwn-ffc41cf8dbb1b895a87daf47d0e5bf6dfbfcab4c.tar.gz lwn-ffc41cf8dbb1b895a87daf47d0e5bf6dfbfcab4c.zip | |
nbd: prevent sock_xmit from attempting to use a NULL socket
NBD does not protect the nbd_device's socket from becoming NULL during
receives.
This closes a race with the NBD_CLEAR_SOCK ioctl (nbd-client -d) setting
the nbd_device's socket to NULL right before NBD calls sock_xmit.
Signed-off-by: Mike Snitzer <snitzer@gmail.com>
Cc: Paul Clements <paul.clements@steeleye.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/block/nbd.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index b53fdb0a282c..60cc54368b66 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -153,6 +153,12 @@ static int sock_xmit(struct nbd_device *lo, int send, void *buf, int size, struct kvec iov; sigset_t blocked, oldset; + if (unlikely(!sock)) { + printk(KERN_ERR "%s: Attempted %s on closed socket in sock_xmit\n", + lo->disk->disk_name, (send ? "send" : "recv")); + return -EINVAL; + } + /* Allow interception of SIGKILL only * Don't allow other signals to interrupt the transmission */ siginitsetinv(&blocked, sigmask(SIGKILL)); |