CVE-2026-43424

01/Description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_tcm: Fix NULL pointer dereferences in nexus handling The `tpg->tpg_nexus` pointer in the USB Target driver is dynamically managed and tied to userspace configuration via ConfigFS. It can be NULL if the USB host sends requests before the nexus is fully established or immediately after it is dropped. Currently, functions like `bot_submit_command()` and the data transfer paths retrieve `tv_nexus = tpg->tpg_nexus` and immediately dereference `tv_nexus->tvn_se_sess` without any validation. If a malicious or misconfigured USB host sends a BOT (Bulk-Only Transport) command during this race window, it triggers a NULL pointer dereference, leading to a kernel panic (local DoS). This exposes an inconsistent API usage within the module, as peer functions like `usbg_submit_command()` and `bot_send_bad_response()` correctly implement a NULL check for `tv_nexus` before proceeding. Fix this by bringing consistency to the nexus handling. Add the missing `if (!tv_nexus)` checks to the vulnerable BOT command and request processing paths, aborting the command gracefully with an error instead of crashing the system.

02/Affected products

linux: linux kernel

03/References7

• git.kernel.org/stable/c/2a2ef846a54a06c33b5c2d4b0d918583e1e7c0b7 Patch
• git.kernel.org/stable/c/3d309b37633c4a847fc149939a2c9576f1aa1065 Patch
• git.kernel.org/stable/c/679d9535aeb15c10bce89c44102004b96624d706 Patch
• git.kernel.org/stable/c/b9b26d7f3aa288cfa54a7bc68612bab1f153f156 Patch
• git.kernel.org/stable/c/b9fde507355342a2d64225d582dc8b98ff5ecb19 Patch
• git.kernel.org/stable/c/d146f27758049fa55ae4c53785a852d3cf7a18d6 Patch
• git.kernel.org/stable/c/f962ca3b020e13d6714f27e8c36fe742441c58d1 Patch