Messages in this thread Patch in this message | | | From | Jeffy Chen <> | Subject | [PATCH v2] xhci: Cleanup current_cmd in xhci_cleanup_command_queue() | Date | Fri, 29 Sep 2017 19:07:57 +0800 |
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KASAN reported use-after-free bug when xhci host controller died: [ 176.952537] BUG: KASAN: use-after-free in xhci_handle_command_timeout+0x68/0x224 [ 176.960846] Write of size 4 at addr ffffffc0cbb01608 by task kworker/3:3/1680 ... [ 177.180644] Freed by task 0: [ 177.183882] kasan_slab_free+0x90/0x15c [ 177.188194] kfree+0x114/0x28c [ 177.191630] xhci_cleanup_command_queue+0xc8/0xf8 [ 177.196916] xhci_hc_died+0x84/0x358
Problem here is that when the cmd_timer fired, it would try to access current_cmd while the command queue is already freed by xhci_hc_died().
Cleanup current_cmd in xhci_cleanup_command_queue() to avoid that.
Fixes: d9f11ba9f107 ("xhci: Rework how we handle unresponsive or hoptlug removed hosts") Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com> ---
Changes in v2: We cannot cancel cmd_timer in xhci_hc_died(), which would cause might_sleep warning.
drivers/usb/host/xhci-ring.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index a9443651ce0f..48ae15afa59e 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1309,6 +1309,7 @@ static void xhci_complete_del_and_free_cmd(struct xhci_command *cmd, u32 status) void xhci_cleanup_command_queue(struct xhci_hcd *xhci) { struct xhci_command *cur_cmd, *tmp_cmd; + xhci->current_cmd = NULL; list_for_each_entry_safe(cur_cmd, tmp_cmd, &xhci->cmd_list, cmd_list) xhci_complete_del_and_free_cmd(cur_cmd, COMP_COMMAND_ABORTED); } -- 2.11.0
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