In the Linux kernel, the following vulnerability has been resolved:
staging: nvec: fix use-after-free in nvec_rx_completed()
In nvec_rx_completed(), when an incomplete RX transfer is detected, nvec_msg_free() is called to return the message back to the pool by clearing its used atomic flag. Immediately after this, the code accesses nvec->rx->data[0] to check the message type.
Since nvec_msg_free() marks the pool slot as available via atomic_set(), any concurrent or subsequent call to nvec_msg_alloc() could claim that same slot and overwrite its data[] array. Reading nvec->rx->data[0] after freeing the message is therefore a use-after-free.
Fix this by saving the message type byte before calling nvec_msg_free(), then using the saved value for the battery quirk check.
References
- https://git.kernel.org/stable/c/08626fcfe12308ca3f8b22c538ba7dee0b2dce7a
- https://git.kernel.org/stable/c/26813881181deb3a32fbb59eadb2599cbe8423f6
- https://git.kernel.org/stable/c/5de04caa46b635e180cecbd164e333eca535db94
- https://git.kernel.org/stable/c/6b2ea886ebdae44a2394029844a4e78f58e1587d
- https://git.kernel.org/stable/c/9f7fe4165a1f1014bdadc8e744c0fd3c2d8c0b89
- https://git.kernel.org/stable/c/a37625c7b688fcf68a54263528eccbabfd7fa17a
- https://git.kernel.org/stable/c/bb3d592c7d6c4ec8ac6640c690ca13298e7e8e90
- https://git.kernel.org/stable/c/f19a5bc059051143c489dd6f79a0f9c3bfd13aea