Re: [PATCH v2 5/8] net: af_can: do not leave a dangling sk pointer in can_create()
flat view
From: Vincent MAILHOL <hidden>
Date: 2024-10-08 02:38:01
Also in:
linux-bluetooth, linux-can, lkml
Hi Ignat, Thanks for the patch. On Tue. 8 Oct. 2024 at 06:37, Ignat Korchagin [off-list ref] wrote:
On error can_create() frees the allocated sk object, but sock_init_data() has already attached it to the provided sock object. This will leave a dangling sk pointer in the sock object and may cause use-after-free later.
I was about to suggest that this should be backported to stable, but after reading the cover letter, I now understand that this patch is more an improvement to avoid false positives on kmemleak & Cie. Maybe the description could be a bit more nuanced? After patch 1/8 of this series, it seems that the use-after-free is not possible anymore.
Signed-off-by: Ignat Korchagin <redacted>
See above comment as notwithstanding. This said: Reviewed-by: Vincent Mailhol <redacted>
quoted hunk ↗ jump to hunk
--- net/can/af_can.c | 1 + 1 file changed, 1 insertion(+)diff --git a/net/can/af_can.c b/net/can/af_can.c index 707576eeeb58..01f3fbb3b67d 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c@@ -171,6 +171,7 @@ static int can_create(struct net *net, struct socket *sock, int protocol, /* release sk on errors */ sock_orphan(sk); sock_put(sk); + sock->sk = NULL; } errout: --2.39.5