CVE-2024-53090 Information

Description

In the Linux kernel the following vulnerability has been resolved:

afs: Fix lock recursion

afs_wake_up_async_call() can incur lock recursion. The problem is that it is called from AF_RXRPC whilst holding the ->notify_lock but it tries to take a ref on the afs_call struct in order to pass it to a work queue - but if the afs_call is already queued we then have an extraneous ref that must be put… calling afs_put_call() may call back down into AF_RXRPC through rxrpc_kernel_shutdown_call() however which might try taking the ->notify_lock again.

This case isn’t very common however so defer it to a workqueue. The oops looks something like:

BUG: spinlock recursion on CPU0 krxrpcio/7001/1646 lock: 0xffff888141399b30 .magic: dead4ead .owner: krxrpcio/7001/1646 .owner_cpu: 0 CPU: 0 UID: 0 PID: 1646 Comm: krxrpcio/7001 Not tainted 6.12.0-rc2-build3+ 4351 Hardware name: ASUS All Series/H97-PLUS BIOS 2306 10/09/2014 Call Trace: dump_stack_lvl+0x47/0x70 do_raw_spin_lock+0x3c/0x90 rxrpc_kernel_shutdown_call+0x83/0xb0 afs_put_call+0xd7/0x180 rxrpc_notify_socket+0xa0/0x190 rxrpc_input_split_jumbo+0x198/0x1d0 rxrpc_input_data+0x14b/0x1e0 ? rxrpc_input_call_packet+0xc2/0x1f0 rxrpc_input_call_event+0xad/0x6b0 rxrpc_input_packet_on_conn+0x1e1/0x210 rxrpc_input_packet+0x3f2/0x4d0 rxrpc_io_thread+0x243/0x410 ? __pfx_rxrpc_io_thread+0x10/0x10 kthread+0xcf/0xe0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x24/0x40 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30

Reference

https://git.kernel.org/stable/c/610a79ffea02102899a1373fe226d949944a7ed6 https://git.kernel.org/stable/c/d7cbf81df996b1eae2dee8deb6df08e2eba78661