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| author | Neil Horman <nhorman@tuxdriver.com> | 2012-01-03 00:31:23 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2012-01-05 04:31:29 +0400 |
| commit | eea915bb0d1358755f151eaefb8208a2d5f3e10c (patch) | |
| tree | 35d593bde3caa1b79751e0ec1a6c6333b2a72506 /drivers/macintosh | |
| parent | 8f257a142fc3868d69de3f996b95d7bdbc509560 (diff) | |
| download | linux-eea915bb0d1358755f151eaefb8208a2d5f3e10c.tar.xz | |
firmware: Fix an oops on reading fw_priv->fw in sysfs loading file
This oops was reported recently:
firmware_loading_store+0xf9/0x17b
dev_attr_store+0x20/0x22
sysfs_write_file+0x101/0x134
vfs_write+0xac/0xf3
sys_write+0x4a/0x6e
system_call_fastpath+0x16/0x1b
The complete backtrace was unfortunately not captured, but details can be found
here:
https://bugzilla.redhat.com/show_bug.cgi?id=769920
The cause is fairly clear.
Its caused by the fact that firmware_loading_store has a case 0 in its
switch statement that reads and writes the fw_priv->fw poniter without the
protection of the fw_lock mutex. since there is a window between the time that
_request_firmware sets fw_priv->fw to NULL and the time the corresponding sysfs
file is unregistered, its possible for a user space application to race in, and
write a zero to the loading file, causing a NULL dereference in
firmware_loading_store. Fix it by extending the protection of the fw_lock mutex
to cover all of the firware_loading_store function.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/macintosh')
0 files changed, 0 insertions, 0 deletions