CVE-2024-53090

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 CPU#0, 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:

<TASK>

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

</TASK>