Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: USB: cdc-acm: skip URB restart in port_shutdown if disconnected acm_port_shutdown() is called from the tty-port machinery whenever the last user closes the port. acm_disconnect() sets acm->disconnected and calls tty_port_tty_vhangup(), which eventually triggers port_shutdown(). At that point acm_disconnect() has already called acm_poison_urbs() and is about to free the control and read URBs. However, acm_port_shutdown() unconditionally calls acm_unpoison_urbs() and, when the ALWAYS_POLL_CTRL quirk is set, immediately re-submits the ctrlurb and all read URBs. If the concurrent acm_disconnect() then frees those URBs and their DMA buffers while they are in-flight, the result is a use-after-free in acm_ctrl_irq() or acm_read_bulk_callback() accessing the freed DMA memory. Fix by checking acm->disconnected after draining the delayed anchor and returning early: if we are in a disconnect path the URBs must remain poisoned and must not be resubmitted. The early return is placed after the delayed-anchor drain loop because that loop only cancels write-side accounting (wb->use = false and autopm counter) and does not touch the hardware path.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 8fb82e3555a7d56a05d8ef0edee9859f889c0860 before d86775e79838d7d2e38ccf506a7d0f8e2dd4d5d0; affected 603d5a7110832e10165d21f9a1486399457177de before 9742905d9ed5bf23ebe4c100dec80b6bc50fb522; affected 5d29d7ff8679e5a525f22da467ba33c042e8029b before a0ed07b5bbb2d8fcef86810453216070691816e7; affected f58752ebcb35e156c85cd1a82d6579c7af3b9023 before 420ca35af891d33522cc08504768ccd60a4c450a; affected f58752ebcb35e156c85cd1a82d6579c7af3b9023 before dc614d6bc991740d41d5a99ac7765c4b675dda88; affected d826061aa64cb28089bf4c73e301dd7928662b84; affected 283f8162cc3c82086537cbc7dc01870dbeb07a91; affected f77f10bc76c2da86b4248269472f6d971e37828b; affected 6.6.136 before 6.6.160; affected 6.12.83 before 6.12.113; affected 6.18.24 before 6.18.56; affected 6.1.175 before 6.2; affected 6.19.14 before 6.20; affected 7.0.1 before 7.1 |
| Linux / Linux | affected 7.1; unaffected 0 before 7.1; unaffected 6.6.160 through 6.6.*; unaffected 6.12.113 through 6.12.*; unaffected 6.18.56 through 6.18.*; unaffected 7.2.10 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/d86775e79838d7d2e38ccf506a7d0f8e2dd4d5d0
- https://git.kernel.org/stable/c/9742905d9ed5bf23ebe4c100dec80b6bc50fb522
- https://git.kernel.org/stable/c/a0ed07b5bbb2d8fcef86810453216070691816e7
- https://git.kernel.org/stable/c/420ca35af891d33522cc08504768ccd60a4c450a
- https://git.kernel.org/stable/c/dc614d6bc991740d41d5a99ac7765c4b675dda88