Description
In the Linux kernel, the following vulnerability has been resolved: rxrpc: Don't move a peeked OOB message onto the pending queue rxrpc_recvmsg_oob() takes a received oob message off recvmsg_oobq and, if a response is needed, moves it onto the pending_oobq tree. However, only the unlink from recvmsg_oobq is guarded by MSG_PEEK; the move onto pending_oobq always runs. As a result, reading a challenge with MSG_PEEK leaves the skb on recvmsg_oobq while also adding it to pending_oobq. Since struct sk_buff's rbnode shares storage with its next and prev pointers, rb_insert_color() overwrites the list linkage, and the skb, which holds a single reference, becomes reachable from both queues at once. When the socket is closed both queues are drained in turn. While draining recvmsg_oobq, __skb_unlink() follows the next and prev pointers that rbnode has overwritten and writes to a bad address. Also, as the skb holds a single reference but is freed from each queue, both the skb and the connection reference it holds are released twice. This leads to memory corruption and to a use-after-free caused by the connection refcount underflow. MSG_PEEK does not consume the message from the queue, so only unlink it from recvmsg_oobq and then move it onto pending_oobq or free it when the message is actually consumed.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
5800b1cf3fd8ccab752a101865be1e76dac33142 to < 9ada3931beb37068fcb725b34b0398457009f343affected5800b1cf3fd8ccab752a101865be1e76dac33142 to < 5f470cc883416fea6d3bce18ef96bf91dd49ffc3affected5800b1cf3fd8ccab752a101865be1e76dac33142 to < 5801cff7d5d7b4e9d877dfb627b23eb63167f02caffected
Linux Linux
Default version status: affected
6.16affected0 to < 6.16unaffected6.18.40 to ≤ 6.18.*unaffected7.1.5 to ≤ 7.1.*unaffected7.2 to ≤ *unaffected