From: Ziyang Xuan <william.xuanziyang@xxxxxxxxxx>
Using wait_event_interruptible() to wait for complete transmission,
but do not check the result of wait_event_interruptible() which can be
interrupted. It will result in TX buffer has multiple accessors and
the later process interferes with the previous process.
Following is one of the problems reported by syzbot.
=============================================================
WARNING: CPU: 0 PID: 0 at net/can/isotp.c:840 isotp_tx_timer_handler+0x2e0/0x4c0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.13.0-rc7+ #68
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014
RIP: 0010:isotp_tx_timer_handler+0x2e0/0x4c0
Call Trace:
<IRQ>
? isotp_setsockopt+0x390/0x390
__hrtimer_run_queues+0xb8/0x610
hrtimer_run_softirq+0x91/0xd0
? rcu_read_lock_sched_held+0x4d/0x80
__do_softirq+0xe8/0x553
irq_exit_rcu+0xf8/0x100
sysvec_apic_timer_interrupt+0x9e/0xc0
</IRQ>
asm_sysvec_apic_timer_interrupt+0x12/0x20
Add result check for wait_event_interruptible() in isotp_sendmsg()
to avoid multiple accessers for tx buffer.
Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Link: https://lore.kernel.org/all/10ca695732c9dd267c76a3c30f37aefe1ff7e32f.1633764159.git.william.xuanziyang@xxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: syzbot+78bab6958a614b0c80b9@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ziyang Xuan <william.xuanziyang@xxxxxxxxxx>
Acked-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
---
net/can/isotp.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/can/isotp.c b/net/can/isotp.c
index caaa532ece94..2ac29c2b2ca6 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -865,7 +865,9 @@ static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
return -EAGAIN;
/* wait for complete transmission of current pdu */
- wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
+ err = wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
+ if (err)
+ return err;
}
if (!size || size > MAX_MSG_LENGTH)
--
2.33.0
