From: Zheyu Ma Date: Sat, 16 Oct 2021 04:02:59 +0000 (+0000) Subject: mwl8k: Fix use-after-free in mwl8k_fw_state_machine() X-Git-Tag: v6.6.17~8953^2~121^2~28 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=257051a235c17e33782b6e24a4b17f2d7915aaec;p=platform%2Fkernel%2Flinux-rpi.git mwl8k: Fix use-after-free in mwl8k_fw_state_machine() When the driver fails to request the firmware, it calls its error handler. In the error handler, the driver detaches device from driver first before releasing the firmware, which can cause a use-after-free bug. Fix this by releasing firmware first. The following log reveals it: [ 9.007301 ] BUG: KASAN: use-after-free in mwl8k_fw_state_machine+0x320/0xba0 [ 9.010143 ] Workqueue: events request_firmware_work_func [ 9.010830 ] Call Trace: [ 9.010830 ] dump_stack_lvl+0xa8/0xd1 [ 9.010830 ] print_address_description+0x87/0x3b0 [ 9.010830 ] kasan_report+0x172/0x1c0 [ 9.010830 ] ? mutex_unlock+0xd/0x10 [ 9.010830 ] ? mwl8k_fw_state_machine+0x320/0xba0 [ 9.010830 ] ? mwl8k_fw_state_machine+0x320/0xba0 [ 9.010830 ] __asan_report_load8_noabort+0x14/0x20 [ 9.010830 ] mwl8k_fw_state_machine+0x320/0xba0 [ 9.010830 ] ? mwl8k_load_firmware+0x5f0/0x5f0 [ 9.010830 ] request_firmware_work_func+0x172/0x250 [ 9.010830 ] ? read_lock_is_recursive+0x20/0x20 [ 9.010830 ] ? process_one_work+0x7a1/0x1100 [ 9.010830 ] ? request_firmware_nowait+0x460/0x460 [ 9.010830 ] ? __this_cpu_preempt_check+0x13/0x20 [ 9.010830 ] process_one_work+0x9bb/0x1100 Signed-off-by: Zheyu Ma Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/1634356979-6211-1-git-send-email-zheyuma97@gmail.com --- diff --git a/drivers/net/wireless/marvell/mwl8k.c b/drivers/net/wireless/marvell/mwl8k.c index 3bf6571..529e325 100644 --- a/drivers/net/wireless/marvell/mwl8k.c +++ b/drivers/net/wireless/marvell/mwl8k.c @@ -5800,8 +5800,8 @@ static void mwl8k_fw_state_machine(const struct firmware *fw, void *context) fail: priv->fw_state = FW_STATE_ERROR; complete(&priv->firmware_loading_complete); - device_release_driver(&priv->pdev->dev); mwl8k_release_firmware(priv); + device_release_driver(&priv->pdev->dev); } #define MAX_RESTART_ATTEMPTS 1