diff options
| author | Ilya Dryomov <idryomov@gmail.com> | 2018-04-24 19:10:55 +0200 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@microsoft.com> | 2018-05-22 21:36:39 -0400 |
| commit | 2e084ef95728eba7f406bdbae37ce7a46e9ac9bd (patch) | |
| tree | dd4d2f7757ba6a0c8ee828c4362891974bf8a477 | |
| parent | 68a1bc21b2275fedbbcee32d85966c727120fe76 (diff) | |
| download | linux-stable-2e084ef95728eba7f406bdbae37ce7a46e9ac9bd.tar.gz | |
libceph: validate con->state at the top of try_write()
[ Upstream commit 9c55ad1c214d9f8c4594ac2c3fa392c1c32431a7 ]
ceph_con_workfn() validates con->state before calling try_read() and
then try_write(). However, try_read() temporarily releases con->mutex,
notably in process_message() and ceph_con_in_msg_alloc(), opening the
window for ceph_con_close() to sneak in, close the connection and
release con->sock. When try_write() is called on the assumption that
con->state is still valid (i.e. not STANDBY or CLOSED), a NULL sock
gets passed to the networking stack:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
IP: selinux_socket_sendmsg+0x5/0x20
Make sure con->state is valid at the top of try_write() and add an
explicit BUG_ON for this, similar to try_read().
Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/23706
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jason Dillaman <dillaman@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
| -rw-r--r-- | net/ceph/messenger.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index d30864a8ed57..1e08c25c43f3 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -2518,6 +2518,11 @@ static int try_write(struct ceph_connection *con) int ret = 1; dout("try_write start %p state %lu\n", con, con->state); + if (con->state != CON_STATE_PREOPEN && + con->state != CON_STATE_CONNECTING && + con->state != CON_STATE_NEGOTIATING && + con->state != CON_STATE_OPEN) + return 0; more: dout("try_write out_kvec_bytes %d\n", con->out_kvec_bytes); @@ -2543,6 +2548,8 @@ more: } more_kvec: + BUG_ON(!con->sock); + /* kvec data queued? */ if (con->out_kvec_left) { ret = write_partial_kvec(con); |