From: Chuck Lever chuck.lever@oracle.com
[ Upstream commit 6cf23783f750634e10daeede48b0f5f5d64ebf3a ]
This tracepoint can crash when dereferencing snd_task because when some transports connect, they put a cookie in that field instead of a pointer to an rpc_task.
BUG: KASAN: use-after-free in trace_event_raw_event_xprt_writelock_event+0x141/0x18e [sunrpc] Read of size 2 at addr ffff8881a83bd3a0 by task git/331872
CPU: 11 PID: 331872 Comm: git Tainted: G S 5.12.0-rc2-00007-g3ab6e585a7f9 #1453 Hardware name: Supermicro SYS-6028R-T/X10DRi, BIOS 1.1a 10/16/2015 Call Trace: dump_stack+0x9c/0xcf print_address_description.constprop.0+0x18/0x239 kasan_report+0x174/0x1b0 trace_event_raw_event_xprt_writelock_event+0x141/0x18e [sunrpc] xprt_prepare_transmit+0x8e/0xc1 [sunrpc] call_transmit+0x4d/0xc6 [sunrpc]
Fixes: 9ce07ae5eb1d ("SUNRPC: Replace dprintk() call site in xprt_prepare_transmit") Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Sasha Levin sashal@kernel.org --- include/trace/events/sunrpc.h | 1 - net/sunrpc/xprt.c | 2 -- 2 files changed, 3 deletions(-)
diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h index 2a03263b5f9d..23db248a7fdb 100644 --- a/include/trace/events/sunrpc.h +++ b/include/trace/events/sunrpc.h @@ -1141,7 +1141,6 @@ DECLARE_EVENT_CLASS(xprt_writelock_event,
DEFINE_WRITELOCK_EVENT(reserve_xprt); DEFINE_WRITELOCK_EVENT(release_xprt); -DEFINE_WRITELOCK_EVENT(transmit_queued);
DECLARE_EVENT_CLASS(xprt_cong_event, TP_PROTO( diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 99d07513237e..586bc9d98de1 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -1441,8 +1441,6 @@ bool xprt_prepare_transmit(struct rpc_task *task) struct rpc_xprt *xprt = req->rq_xprt;
if (!xprt_lock_write(xprt, task)) { - trace_xprt_transmit_queued(xprt, task); - /* Race breaker: someone may have transmitted us */ if (!test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) rpc_wake_up_queued_task_set_status(&xprt->sending,