CVE-2026-43423 PUBLISHED

usb: gadget: f_ncm: Fix atomic context locking issue

Assigner: Linux
Reserved: 01.05.2026 Published: 08.05.2026 Updated: 08.05.2026

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

usb: gadget: f_ncm: Fix atomic context locking issue

The ncm_set_alt function was holding a mutex to protect against races with configfs, which invokes the might-sleep function inside an atomic context.

Remove the struct net_device pointer from the f_ncm_opts structure to eliminate the contention. The connection state is now managed by a new boolean flag to preserve the use-after-free fix from commit 6334b8e4553c ("usb: gadget: f_ncm: Fix UAF ncm object at re-bind after usb ep transport error").

BUG: sleeping function called from invalid context Call Trace: dump_stack_lvl+0x83/0xc0 dump_stack+0x14/0x16 __might_resched+0x389/0x4c0 __might_sleep+0x8e/0x100 ... __mutex_lock+0x6f/0x1740 ... ncm_set_alt+0x209/0xa40 set_config+0x6b6/0xb40 composite_setup+0x734/0x2b40 ...

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from b62076e780a2121903ecf9ffdfb89c64647cb7da to e533a44fb1b337d14f772585b67328bee2e0b5e3 (excl.)
  • affected from 188338c1827842f898761a939669cf345bdf07e2 to e95120b4b95ef1c16d8e94e201ae89f5e59e2612 (excl.)
  • affected from 56a512a9b4107079f68701e7d55da8507eb963d9 to 0d6c8144ca4d93253de952a5ea0028c19ed7ab68 (excl.)
Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 6.18.17 to 6.18.19 (excl.)
  • affected from 6.19.7 to 6.19.9 (excl.)

References