brain-hackers_pepepper-mirror/linux-brain
1
0
Fork 0
mirror of https://github.com/brain-hackers/linux-brain.git synced 2024-06-09 23:36:23 +09:00
Code Issues Projects Releases Wiki Activity

rxrpc: Fix call ref leak

Browse Source 
commit c48fc11b69 upstream.

When sendmsg() finds a call to continue on with, if the call is in an
inappropriate state, it doesn't release the ref it just got on that call
before returning an error.

This causes the following symptom to show up with kasan:

	BUG: KASAN: use-after-free in rxrpc_send_keepalive+0x8a2/0x940
	net/rxrpc/output.c:635
	Read of size 8 at addr ffff888064219698 by task kworker/0:3/11077

where line 635 is:

	whdr.epoch	= htonl(peer->local->rxnet->epoch);

The local endpoint (which cannot be pinned by the call) has been released,
but not the peer (which is pinned by the call).

Fix this by releasing the call in the error path.

Fixes: 37411cad63 ("rxrpc: Fix potential NULL-pointer exception")
Reported-by: syzbot+d850c266e3df14da1d31@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
David Howells 2019-10-07 10:58:28 +01:00 committed by Greg Kroah-Hartman
parent c87091ed19
commit 43159c9ec1
1 changed files with 1 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
net/rxrpc/sendmsg.c
View File

@ -586,6 +586,7 @@ int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
case RXRPC_CALL_SERVER_PREALLOC:
case RXRPC_CALL_SERVER_SECURING:
case RXRPC_CALL_SERVER_ACCEPTING:
rxrpc_put_call(call, rxrpc_call_put);
ret = -EBUSY;
goto error_release_sock;
default: