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| author | Maxime Bizon <mbizon@freebox.fr> | 2013-08-29 20:28:13 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-08-30 12:04:27 -0700 |
| commit | 1eeeef153c02f5856ec109fa532eb5f31c39f85c (patch) | |
| tree | 4ba21b5842f9a986ac85105c2787c50d2a8dae09 | |
| parent | 7315f0ccfc283ae998ca4d8102de83bba21936fa (diff) | |
| download | op-kernel-dev-1eeeef153c02f5856ec109fa532eb5f31c39f85c.zip op-kernel-dev-1eeeef153c02f5856ec109fa532eb5f31c39f85c.tar.gz | |
firmware loader: fix pending_fw_head list corruption
Got the following oops just before reboot:
Unable to handle kernel NULL pointer dereference at virtual address 00000000
[<8028d300>] (__list_del_entry+0x44/0xac)
[<802e3320>] (__fw_load_abort.part.13+0x1c/0x50)
[<802e337c>] (fw_shutdown_notify+0x28/0x50)
[<80034f80>] (notifier_call_chain.isra.1+0x5c/0x9c)
[<800350ec>] (__blocking_notifier_call_chain+0x44/0x58)
[<80035114>] (blocking_notifier_call_chain+0x14/0x18)
[<80035d64>] (kernel_restart_prepare+0x14/0x38)
[<80035d94>] (kernel_restart+0xc/0x50)
The following race condition triggers here:
_request_firmware_load()
device_create_file(...)
kobject_uevent(...)
(schedule)
(resume)
firmware_loading_store(1)
firmware_loading_store(0)
list_del_init(&buf->pending_list)
(schedule)
(resume)
list_add(&buf->pending_list, &pending_fw_head);
wait_for_completion(&buf->completion);
causing an oops later when walking pending_list after the firmware has
been released.
The proposed fix is to move the list_add() before sysfs attribute
creation.
Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Acked-by: Ming Lei <ming.lei@canonical.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/base/firmware_class.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index e4107d5..10a4467 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -865,8 +865,15 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent, goto err_del_dev; } + mutex_lock(&fw_lock); + list_add(&buf->pending_list, &pending_fw_head); + mutex_unlock(&fw_lock); + retval = device_create_file(f_dev, &dev_attr_loading); if (retval) { + mutex_lock(&fw_lock); + list_del_init(&buf->pending_list); + mutex_unlock(&fw_lock); dev_err(f_dev, "%s: device_create_file failed\n", __func__); goto err_del_bin_attr; } @@ -881,10 +888,6 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent, kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD); } - mutex_lock(&fw_lock); - list_add(&buf->pending_list, &pending_fw_head); - mutex_unlock(&fw_lock); - wait_for_completion(&buf->completion); cancel_delayed_work_sync(&fw_priv->timeout_work); |
