From: Chengfeng Ye Date: Thu, 30 Jul 2026 08:32:02 +0000 (+0800) Subject: Bluetooth: hci_event: fix LE list UAF on reset X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=39a3afb91be3cb465f46ce7a8e5696d9e33edf93;p=linux Bluetooth: hci_event: fix LE list UAF on reset commit 33af47e847fe4a28b109673affb5874015d54f5a upstream. hci_cc_reset() clears the LE accept and resolving lists without taking hdev->lock. Other command-complete handlers serialize updates to these lists with that lock, and the debugfs readers hold it while walking them. This permits the reset completion and a debugfs read to interleave as follows: hci_rx_work debugfs reader ----------- -------------- lock hdev->lock fetch current entry list_del(entry) kfree(entry) read entry fields The reader then dereferences a freed list entry and may follow its stale next pointer. KASAN reported: BUG: KASAN: slab-use-after-free in white_list_show+0x15f/0x180 Read of size 1 at addr ffff8881015dab16 by task poc/95 Call Trace: white_list_show+0x15f/0x180 seq_read_iter+0x3ff/0x1190 seq_read+0x267/0x3d0 vfs_read+0x177/0xa20 ksys_read+0xf7/0x1c0 Allocated by task 91: hci_bdaddr_list_add+0x1a6/0x3a0 hci_cc_le_add_to_accept_list+0xab/0x140 hci_cmd_complete_evt+0x26c/0x9a0 hci_event_packet+0x454/0xb20 hci_rx_work+0x293/0x730 Freed by task 90: kfree+0x131/0x3c0 hci_bdaddr_list_clear+0xd8/0x160 hci_cc_reset+0x28a/0x370 hci_cmd_complete_evt+0x26c/0x9a0 hci_event_packet+0x454/0xb20 hci_rx_work+0x293/0x730 Take hdev->lock around both list clears. This matches the existing mutation and traversal locking convention. Fixes: a4d5504d5c39 ("Bluetooth: Clear LE white list when resetting controller") Fixes: cfdb0c2d095a ("Bluetooth: Store Resolv list size") Cc: stable@vger.kernel.org Signed-off-by: Chengfeng Ye Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index ce89f7cbebc7d..ab940c812cece 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -293,8 +293,10 @@ static u8 hci_cc_reset(struct hci_dev *hdev, void *data, struct sk_buff *skb) hdev->ssp_debug_mode = 0; + hci_dev_lock(hdev); hci_bdaddr_list_clear(&hdev->le_accept_list); hci_bdaddr_list_clear(&hdev->le_resolv_list); + hci_dev_unlock(hdev); return rp->status; }