[PATCH AUTOSEL 4.9 093/251] drivers/rapidio/rio_cm.c: fix potential oops in riocm_ch_listen()

Sasha Levin
2020-01-16T18:10:37Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 5ac188b12e7cbdd92dee60877d1fac913fc1d074 ]

If riocm_get_channel() fails, then we should just return -EINVAL.
Calling riocm_put_channel() will trigger a NULL dereference and
generally we should call put() if the get() didn't succeed.

Link: http://lkml.kernel.org/r/20190110130230.GB27017@kadam
Fixes: b6e8d4aa1110 ("rapidio: add RapidIO channelized messaging driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/rapidio/rio_cm.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/rapidio/rio_cm.c b/drivers/rapidio/rio_cm.c
index ef989a15aefc..b29fc258eeba 100644
--- a/drivers/rapidio/rio_cm.c
+++ b/drivers/rapidio/rio_cm.c
@@ -1215,7 +1215,9 @@ static int riocm_ch_listen(u16 ch_id)
riocm_debug(CHOP, "(ch_%d)", ch_id);

ch = riocm_get_channel(ch_id);
- if (!ch || !riocm_cmp_exch(ch, RIO_CM_CHAN_BOUND, RIO_CM_LISTEN))
+ if (!ch)
+ return -EINVAL;
+ if (!riocm_cmp_exch(ch, RIO_CM_CHAN_BOUND, RIO_CM_LISTEN))
ret = -EINVAL;
riocm_put_channel(ch);
return ret;
--
2.20.1