Wind River Support Network

Description

In the Linux kernel, the following vulnerability has been resolved:

usb: atm: cxacru: fix a flaw in existing endpoint checks

Syzbot once again identified a flaw in usb endpoint checking, see 1].
This time the issue stems from a commit authored by me (2eabb655a968
("usb: atm: cxacru: fix endpoint checking in cxacru_bind()")).

While using usb_find_common_endpoints() may usually be enough to
discard devices with wrong endpoints, in this case one needs more
than just finding and identifying the sufficient number of endpoints
of correct types - one needs to check the endpoint's address as well.

Since cxacru_bind() fills URBs with CXACRU_EP_CMD address in mind,
switch the endpoint verification approach to usb_check_XXX_endpoints()
instead to fix incomplete ep testing.

[1] Syzbot report:
usb 5-1: BOGUS urb xfer, pipe 3 != type 1
WARNING: CPU: 0 PID: 1378 at drivers/usb/core/urb.c:504 usb_submit_urb+0xc4e/0x18c0 drivers/usb/core/urb.c:503
...
RIP: 0010:usb_submit_urb+0xc4e/0x18c0 drivers/usb/core/urb.c:503
...
Call Trace:
 <TASK>
 cxacru_cm+0x3c8/0xe50 drivers/usb/atm/cxacru.c:649
 cxacru_card_status drivers/usb/atm/cxacru.c:760 [inline]
 cxacru_bind+0xcf9/0x1150 drivers/usb/atm/cxacru.c:1223
 usbatm_usb_probe+0x314/0x1d30 drivers/usb/atm/usbatm.c:1058
 cxacru_usb_probe+0x184/0x220 drivers/usb/atm/cxacru.c:1377
 usb_probe_interface+0x641/0xbb0 drivers/usb/core/driver.c:396
 really_probe+0x2b9/0xad0 drivers/base/dd.c:658
 __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:800
 driver_probe_device+0x50/0x430 drivers/base/dd.c:830
...

CREATE(Triage):(User=admin) [CVE-2025-21916 (https://nvd.nist.gov/vuln/detail/CVE-2025-21916)

CVEs

• CVE-2025-21916