]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/commitdiff
rxrpc: Fix call ref leak
authorDavid Howells <dhowells@redhat.com>
Mon, 7 Oct 2019 09:58:28 +0000 (10:58 +0100)
committerKhalid Elmously <khalid.elmously@canonical.com>
Wed, 13 Nov 2019 23:47:34 +0000 (18:47 -0500)
BugLink: https://bugs.launchpad.net/bugs/1852492
commit c48fc11b69e95007109206311b0187a3090591f3 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: 37411cad633f ("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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
net/rxrpc/sendmsg.c

index eee43ed1d7013a6141fcc9a7e06b39d27c6fc843..3e459a225b9f863c991ac5bd625ae5a97a28215d 100644 (file)
@@ -657,6 +657,7 @@ 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: