On Thu, 5 Dec 2024 at 15:12, Greg KH gregkh@linuxfoundation.org wrote:
On Thu, Dec 05, 2024 at 01:07:58PM +0000, Benoît Sevens wrote:
From: Takashi Iwai tiwai@suse.de
Upstream commit a3dd4d63eeb452cfb064a13862fb376ab108f6a6
The current USB-audio driver code doesn't check bLength of each descriptor at traversing for clock descriptors. That is, when a device provides a bogus descriptor with a shorter bLength, the driver might hit out-of-bounds reads.
For addressing it, this patch adds sanity checks to the validator functions for the clock descriptor traversal. When the descriptor length is shorter than expected, it's skipped in the loop.
For the clock source and clock multiplier descriptors, we can just check bLength against the sizeof() of each descriptor type. OTOH, the clock selector descriptor of UAC2 and UAC3 has an array of bNrInPins elements and two more fields at its tail, hence those have to be checked in addition to the sizeof() check.
This patch ports the upstream commit a3dd4d63eeb4 to trees that do not include the refactoring commit 9ec730052fa2 ("ALSA: usb-audio: Refactoring UAC2/3 clock setup code"). That commit provides union objects for pointing both UAC2 and UAC3 objects and unifies the clock source, selector and multiplier helper functions. This means we need to perform the check in each version specific helper function, but on the other hand do not need to do version specific union dereferencing in the macros and helper functions.
Reported-by: Benoît Sevens bsevens@google.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/20241121140613.3651-1-bsevens@google.com Link: https://patch.msgid.link/20241125144629.20757-1-tiwai@suse.de Signed-off-by: Takashi Iwai tiwai@suse.de (cherry picked from commit a3dd4d63eeb452cfb064a13862fb376ab108f6a6) Signed-off-by: Benoît Sevens bsevens@google.com
sound/usb/clock.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-)
What changed in v2?
Only the commit description. Should I resend it in that case in reply to the previous thread?