commit 33af47e 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: a4d5504 ("Bluetooth: Clear LE white list when resetting controller") Fixes: cfdb0c2 ("Bluetooth: Store Resolv list size") Cc: stable@vger.kernel.org Signed-off-by: Chengfeng Ye <nicoyip.dev@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Original file line number	Diff line number	Diff line change
`@@ -297,8 +297,10 @@ static u8 hci_cc_reset(struct hci_dev hdev, void data, struct sk_buff *skb)`
`297`	`297`
`298`	`298`	`hdev->ssp_debug_mode = 0;`
`299`	`299`
	`300`	`+ hci_dev_lock(hdev);`
`300`	`301`	`hci_bdaddr_list_clear(&hdev->le_accept_list);`
`301`	`302`	`hci_bdaddr_list_clear(&hdev->le_resolv_list);`
	`303`	`+ hci_dev_unlock(hdev);`
`302`	`304`
`303`	`305`	`return rp->status;`
`304`	`306`	`}`