Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
ALSA: bcd2000: Fix a UAF bug on the error path of probing
When the driver fails in snd_card_register() at probe time, it will free the ‘bcd2k->midi_out_urb’ before killing it, which may cause a UAF bug.
The following log can reveal it:
[ 50.727020] BUG: KASAN: use-after-free in bcd2000_input_complete+0x1f1/0x2e0 [snd_bcd2000] [ 50.727623] Read of size 8 at addr ffff88810fab0e88 by task swapper/4/0 [ 50.729530] Call Trace: [ 50.732899] bcd2000_input_complete+0x1f1/0x2e0 [snd_bcd2000]
Fix this by adding usb_kill_urb() before usb_free_urb().
Details
- Affected product:
- CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CloudLinux 7 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , Ubuntu 16.04 ELS
- Affected packages:
- linux @ 4.4.0 (+8 more)
In the Linux kernel, the following vulnerability has been resolved:
ALSA: bcd2000: Fix a UAF bug on the error path of probing
When the driver fails in snd_card_register() at probe time, it will free the ‘bcd2k->midi_out_urb’ before killing it, which may cause a UAF bug.
The following log can reveal it:
[ 50.727020] BUG: KASAN: use-after-free in bcd2000_input_complete+0x1f1/0x2e0 [snd_bcd2000] [ 50.727623] Read of size 8 at addr ffff88810fab0e88 by task swapper/4/0 [ 50.729530] Call Trace: [ 50.732899] bcd2000_input_complete+0x1f1/0x2e0 [snd_bcd2000]
Fix this by adding usb_kill_urb() before usb_free_urb().