| commit | 52565a935213cd6a8662ddb8efe5b4219343a25d | [log] [tgz] |
|---|---|---|
| author | Sven Stegemann <sven@stegemann.de> | Tue Aug 12 21:18:03 2025 +0200 |
| committer | Jakub Kicinski <kuba@kernel.org> | Wed Aug 13 18:18:33 2025 -0700 |
| tree | d54122d658e7e78478dd7563ee94de9da9f54f9d | |
| parent | 1c756093cdc1fd9973e156f527a08731795d41a2 [diff] |
net: kcm: Fix race condition in kcm_unattach()
syzbot found a race condition when kcm_unattach(psock)
and kcm_release(kcm) are executed at the same time.
kcm_unattach() is missing a check of the flag
kcm->tx_stopped before calling queue_work().
If the kcm has a reserved psock, kcm_unattach() might get executed
between cancel_work_sync() and unreserve_psock() in kcm_release(),
requeuing kcm->tx_work right before kcm gets freed in kcm_done().
Remove kcm->tx_stopped and replace it by the less
error-prone disable_work_sync().
Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module")
Reported-by: syzbot+e62c9db591c30e174662@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=e62c9db591c30e174662
Reported-by: syzbot+d199b52665b6c3069b94@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=d199b52665b6c3069b94
Reported-by: syzbot+be6b1fdfeae512726b4e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=be6b1fdfeae512726b4e
Signed-off-by: Sven Stegemann <sven@stegemann.de>
Link: https://patch.msgid.link/20250812191810.27777-1-sven@stegemann.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>