CVE-2026-74456can: peak_usb: peak_usb_start(): fix double free of transfer buffer on URB submit error

Official description

In the Linux kernel, the following vulnerability has been resolved: can: peak_usb: peak_usb_start(): fix double free of transfer buffer on URB submit error In peak_usb_start(), each RX URB transfer buffer is allocated with kmalloc() and the URB is flagged URB_FREE_BUFFER so that the final usb_free_urb() also frees the transfer buffer. If usb_submit_urb() fails, the error path frees the buffer explicitly with kfree(buf) and then calls usb_free_urb(urb). Because URB_FREE_BUFFER is set, usb_free_urb() -> urb_destroy() frees the same buffer a second time, a double free of the transfer buffer. BUG: KASAN: double-free in usb_free_urb.part.0+0x91/0xb0 Free of addr ffff8881069ccb80 by task trigger.sh/285 Call Trace: kfree+0x113/0x3c0 usb_free_urb.part.0+0x91/0xb0 Drop the redundant kfree(buf); usb_free_urb() already releases the transfer buffer. This mirrors commit 03819abbeb11 ("net: usb: lan78xx: Fix double free issue with interrupt buffer allocation").

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/914c3b8fa175acf8476ad31cf04e308638e3578e
• https://git.kernel.org/stable/c/5f2fa5840c34d3a558c57855781be75e03bef752
• https://git.kernel.org/stable/c/b9088d581fff971a7eb1628f8dcc30df6cfef4dc
• https://git.kernel.org/stable/c/525640b93d3e5f82f4ebea4730f4e0cf799522ba
• https://git.kernel.org/stable/c/4bb3325075138dd5346b71589a959878b564dc0b
• https://git.kernel.org/stable/c/92d0de80ca2223b9c7da78020155b6cb27824cc0
• https://git.kernel.org/stable/c/dfb17bf04a764462000f11258a7c06aa92d1f261
• https://git.kernel.org/stable/c/9b3d5a6d952c38bbcf07f903cbeadefdb56b9bc9