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| author |   Anirudh Rayabharam <mail@anirudhrb.com> | 2021-07-28 14:21:07 +0530 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-29 17:22:15 +0200 |
| commit | 75d95e2e39b27f733f21e6668af1c9893a97de5e (patch) | |
| tree | 75667c482702d99a48b22fe93b75f8f0a01ad24a /drivers/base/firmware_loader/main.c | |
| parent | firmware_loader: use -ETIMEDOUT instead of -EAGAIN in fw_load_sysfs_fallback (diff) | |
| download | linux-dev-75d95e2e39b27f733f21e6668af1c9893a97de5e.tar.xz linux-dev-75d95e2e39b27f733f21e6668af1c9893a97de5e.zip | |
firmware_loader: fix use-after-free in firmware_fallback_sysfs
This use-after-free happens when a fw_priv object has been freed but
hasn't been removed from the pending list (pending_fw_head). The next
time fw_load_sysfs_fallback tries to insert into the list, it ends up
accessing the pending_list member of the previously freed fw_priv.
The root cause here is that all code paths that abort the fw load
don't delete it from the pending list. For example:
_request_firmware()
-> fw_abort_batch_reqs()
-> fw_state_aborted()
To fix this, delete the fw_priv from the list in __fw_set_state() if
the new state is DONE or ABORTED. This way, all aborts will remove
the fw_priv from the list. Accordingly, remove calls to list_del_init
that were being made before calling fw_state_(aborted|done).
Also, in fw_load_sysfs_fallback, don't add the fw_priv to the pending
list if it is already aborted. Instead, just jump out and return early.
Fixes: bcfbd3523f3c ("firmware: fix a double abort case with fw_load_sysfs_fallback")
Cc: stable <stable@vger.kernel.org>
Reported-by: syzbot+de271708674e2093097b@syzkaller.appspotmail.com
Tested-by: syzbot+de271708674e2093097b@syzkaller.appspotmail.com
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
Link: https://lore.kernel.org/r/20210728085107.4141-3-mail@anirudhrb.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base/firmware_loader/main.c')
| -rw-r--r-- | drivers/base/firmware_loader/main.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c index 4fdb8219cd08..68c549d71230 100644 --- a/drivers/base/firmware_loader/main.c +++ b/drivers/base/firmware_loader/main.c @@ -783,8 +783,10 @@ static void fw_abort_batch_reqs(struct firmware *fw) return; fw_priv = fw->priv; + mutex_lock(&fw_lock); if (!fw_state_is_aborted(fw_priv)) fw_state_aborted(fw_priv); + mutex_unlock(&fw_lock); } /* called from request_firmware() and request_firmware_work_func() */ |