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| author | Ilya Dryomov <idryomov@gmail.com> | 2018-04-24 19:10:55 +0200 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2018-04-26 17:39:08 +0200 |
| commit | 9c55ad1c214d9f8c4594ac2c3fa392c1c32431a7 (patch) | |
| tree | 1520b5b53003aa6bfee5e8afc255cd73061ffc2d /net | |
| parent | libceph: reschedule a tick in finish_hunting() (diff) | |
| download | linux-9c55ad1c214d9f8c4594ac2c3fa392c1c32431a7.tar.xz linux-9c55ad1c214d9f8c4594ac2c3fa392c1c32431a7.zip | |
libceph: validate con->state at the top of try_write()
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>
Diffstat (limited to 'net')
| -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 fcb40c12b1f8..3b3d33ea9ed8 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -2569,6 +2569,11 @@ 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); @@ -2594,6 +2599,8 @@ more: } more_kvec: + BUG_ON(!con->sock); + /* kvec data queued? */ if (con->out_kvec_left) { ret = write_partial_kvec(con); |