Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: blk-mq: pop cached request if it is usable When submitting a bio to blk-mq, if the task should sleep after peeking a cached request, but before it pops it, the plug flushes and calls blk_mq_free_plug_rqs, freeing the cached_rqs. This creates a use-after-free bug. Fix this by popping the cached request before any possible blocking calls if it is suitable for use. Popping this request first holds a queue reference, so avoid any serialization races with queue freezes and can safely proceed with dispatching that request to the driver. This potentially increases a timing window from when a driver wants to freeze its queue to when requests stop being dispatched. That scenario is off the fast path though, and drivers need to appropriately handle requests during a freeze request anyway. The downside is the popped element needs to be individually freed when we performed a bio plug merge. The cached request would have had to be freed later anyway, but this patch does it inline with building the plug list instead of after flushing it.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected b0077e269f6c152e807fdac90b58caf012cdbaab before 23d8ea1e303b5f32d883757a4a707e791dbc9808; affected b0077e269f6c152e807fdac90b58caf012cdbaab before 97e2d08de282ef76f84ab4ccd00f1acb3f5f999e; affected b0077e269f6c152e807fdac90b58caf012cdbaab before 388468f7e7d1eab092cf2a39fdfb502e52019ec6; affected b0077e269f6c152e807fdac90b58caf012cdbaab before dc278e9bf2b9513a763353e6b9cc21e0f532954e; affected b5c8e0ff76d10f6bf70a7237678f27c20cf59bc9; affected e9c309ded295b7f8849097d71ae231456ca79f78; affected b80056bd75a16e4550873ecefe12bc8fd190b1cf; affected 33cf52b6e53a6aa55883aa7fb9ceffceff8488a6; affected 8b6075046470c8756242dfe3fd058813636f69a3; affected 6.1.72 before 6.2; affected 6.5.13 before 6.6; affected 6.6.3 before 6.7; affected 6.1.75 before 6.2; affected 6.6.14 before 6.7 |
| Linux / Linux | affected 6.7; unaffected 0 before 6.7; unaffected 6.12.104 through 6.12.*; unaffected 6.18.45 through 6.18.*; unaffected 7.0.11 through 7.0.*; unaffected 7.1 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/23d8ea1e303b5f32d883757a4a707e791dbc9808
- https://git.kernel.org/stable/c/97e2d08de282ef76f84ab4ccd00f1acb3f5f999e
- https://git.kernel.org/stable/c/388468f7e7d1eab092cf2a39fdfb502e52019ec6
- https://git.kernel.org/stable/c/dc278e9bf2b9513a763353e6b9cc21e0f532954e
ADP enrichment
No English description supplied.
No references supplied.