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ALSA: bcd2000: Fix a UAF bug on the error path of probing
jira VULN-70295 cve CVE-2022-50229 commit-author Zheyu Ma <zheyuma97@gmail.com> commit ffb2759 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(). Fixes: b47a222 ("ALSA: MIDI driver for Behringer BCD2000 USB device") Signed-off-by: Zheyu Ma <zheyuma97@gmail.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20220715010515.2087925-1-zheyuma97@gmail.com Signed-off-by: Takashi Iwai <tiwai@suse.de> (cherry picked from commit ffb2759) Signed-off-by: Roxana Nicolescu <rnicolescu@ciq.com> Signed-off-by: Roxana Nicolescu <rnicolescu@ciq.com>
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sound/usb/bcd2000/bcd2000.c

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -348,7 +348,8 @@ static int bcd2000_init_midi(struct bcd2000 *bcd2k)
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static void bcd2000_free_usb_related_resources(struct bcd2000 *bcd2k,
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struct usb_interface *interface)
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{
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/* usb_kill_urb not necessary, urb is aborted automatically */
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usb_kill_urb(bcd2k->midi_out_urb);
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usb_kill_urb(bcd2k->midi_in_urb);
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usb_free_urb(bcd2k->midi_out_urb);
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usb_free_urb(bcd2k->midi_in_urb);

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