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| author | David Howells <dhowells@redhat.com> | 2019-08-10 00:47:47 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-08-29 09:30:28 +0300 |
| commit | 85a55331d9aeb1f91ef71620be92ab52c72e8acd (patch) | |
| tree | 05a13e321a29e5ddd7889d1b86f7184c4735bb65 | |
| parent | fa321a9ce5992f2ba336c5bf032e874e7b81b0b2 (diff) | |
| download | linux-85a55331d9aeb1f91ef71620be92ab52c72e8acd.tar.xz | |
rxrpc: Fix local refcounting
[ Upstream commit 68553f1a6f746bf860bce3eb42d78c26a717d9c0 ]
Fix rxrpc_unuse_local() to handle a NULL local pointer as it can be called
on an unbound socket on which rx->local is not yet set.
The following reproduced (includes omitted):
int main(void)
{
socket(AF_RXRPC, SOCK_DGRAM, AF_INET);
return 0;
}
causes the following oops to occur:
BUG: kernel NULL pointer dereference, address: 0000000000000010
...
RIP: 0010:rxrpc_unuse_local+0x8/0x1b
...
Call Trace:
rxrpc_release+0x2b5/0x338
__sock_release+0x37/0xa1
sock_close+0x14/0x17
__fput+0x115/0x1e9
task_work_run+0x72/0x98
do_exit+0x51b/0xa7a
? __context_tracking_exit+0x4e/0x10e
do_group_exit+0xab/0xab
__x64_sys_exit_group+0x14/0x17
do_syscall_64+0x89/0x1d4
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Reported-by: syzbot+20dee719a2e090427b5f@syzkaller.appspotmail.com
Fixes: 730c5fd42c1e ("rxrpc: Fix local endpoint refcounting")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/rxrpc/local_object.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c index 68e9342fd433..72a6e12a9304 100644 --- a/net/rxrpc/local_object.c +++ b/net/rxrpc/local_object.c @@ -403,11 +403,13 @@ void rxrpc_unuse_local(struct rxrpc_local *local) { unsigned int au; - au = atomic_dec_return(&local->active_users); - if (au == 0) - rxrpc_queue_local(local); - else - rxrpc_put_local(local); + if (local) { + au = atomic_dec_return(&local->active_users); + if (au == 0) + rxrpc_queue_local(local); + else + rxrpc_put_local(local); + } } /* |