Commit 257051a2 authored by Zheyu Ma's avatar Zheyu Ma Committed by Kalle Valo

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: default avatarZheyu Ma <zheyuma97@gmail.com>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1634356979-6211-1-git-send-email-zheyuma97@gmail.com
parent 515e7184
......@@ -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
......
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