From dfc7f7a988dad34c3bf4c053124fb26aa6c5f916 Mon Sep 17 00:00:00 2001
From: Jeremy Cline <jeremy@jcline.org>
Date: Fri, 8 Sep 2023 19:58:53 -0400
Subject: [PATCH] net: nfc: llcp: Add lock when modifying device list
Git-commit: dfc7f7a988dad34c3bf4c053124fb26aa6c5f916
Patch-mainline: v6.6-rc5
References: git-fixes CVE-2023-52524 bsc#1220927
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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 f60e424e0607..6705bb895e23 100644
--- a/net/nfc/llcp_core.c
+++ b/net/nfc/llcp_core.c
@@ -1636,7 +1636,9 @@ 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;
}
--
2.35.3