5.4-stable review patch. If anyone has any objections, please let me know.
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From: Jeremy Cline jeremy@jcline.org
[ Upstream commit dfc7f7a988dad34c3bf4c053124fb26aa6c5f916 ]
The device list needs its associated lock held when modifying it, or the list could become corrupted, as syzbot discovered.
Reported-and-tested-by: syzbot+c1d0a03d305972dbbe14@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=c1d0a03d305972dbbe14 Signed-off-by: Jeremy Cline jeremy@jcline.org Reviewed-by: Simon Horman horms@kernel.org Fixes: 6709d4b7bc2e ("net: nfc: Fix use-after-free caused by nfc_llcp_find_local") Link: https://lore.kernel.org/r/20230908235853.1319596-1-jeremy@jcline.org Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/nfc/llcp_core.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/nfc/llcp_core.c b/net/nfc/llcp_core.c index ddfd159f64e13..b1107570eaee8 100644 --- a/net/nfc/llcp_core.c +++ b/net/nfc/llcp_core.c @@ -1646,7 +1646,9 @@ int nfc_llcp_register_device(struct nfc_dev *ndev) timer_setup(&local->sdreq_timer, nfc_llcp_sdreq_timer, 0); INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work);
+ spin_lock(&llcp_devices_lock); list_add(&local->list, &llcp_devices); + spin_unlock(&llcp_devices_lock);
return 0; }