Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Fix Use-After-Free in AIO error path In ffs_epfile_write_iter() and ffs_epfile_read_iter(), when ffs_epfile_io() fails with an error other than -EIOCBQUEUED, the io_data structure (`p`) is freed. However, for AIO operations, the kiocb cancel function was already armed and kiocb->private was set to `p`. If a concurrent cancel operation (such as sys_io_cancel()) executes after ffs_epfile_io() fails but before the function frees `p`, a Use-After-Free can occur when the cancellation handler accesses the freed pointer. To securely fix this race condition, we must properly un-arm the cancellation. Invoking `kiocb->ki_complete()` does exactly this by acquiring `ctx->ctx_lock` and safely removing the kiocb from the active sequence. In doing so, it ensures that a parallel io_cancel can no longer discover the kiocb, effectively closing the race window. We then return -EIOCBQUEUED to notify the VFS layer that the kiocb has been consumed and it should avoid attempting to complete the request again or triggering subsequent completion handlers.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected de2080d41b5d584205e408d72021f0f335a046fc before 0a2f71ccf9c2053de725e9a7922d081f3f3a3804; affected de2080d41b5d584205e408d72021f0f335a046fc before b5f0e80a03e87bd932487e03248eae3ba3ed7b45; affected de2080d41b5d584205e408d72021f0f335a046fc before 153b5ecd29ed055562400bc17c91df3fd869b0ce; affected de2080d41b5d584205e408d72021f0f335a046fc before 4a2fb2d12b87b43724230abb52a1440617c7b6cc; affected de2080d41b5d584205e408d72021f0f335a046fc before e78dcb1f7ec271449c54984dc90c62a5ba272de7 |
| Linux / Linux | affected 4.0; unaffected 0 before 4.0; unaffected 6.6.160 through 6.6.*; unaffected 6.12.111 through 6.12.*; unaffected 6.18.51 through 6.18.*; unaffected 7.2.5 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/0a2f71ccf9c2053de725e9a7922d081f3f3a3804
- https://git.kernel.org/stable/c/b5f0e80a03e87bd932487e03248eae3ba3ed7b45
- https://git.kernel.org/stable/c/153b5ecd29ed055562400bc17c91df3fd869b0ce
- https://git.kernel.org/stable/c/4a2fb2d12b87b43724230abb52a1440617c7b6cc
- https://git.kernel.org/stable/c/e78dcb1f7ec271449c54984dc90c62a5ba272de7