CVE-2022-49321

In the Linux kernel, the following vulnerability has been resolved:

xprtrdma: treat all calls not a bcall when bc_serv is NULL

When a rdma server returns a fault format reply, nfs v3 client may

treats it as a bcall when bc service is not exist.

The debug message at rpcrdma_bc_receive_call are,

[56579.837169] RPC: rpcrdma_bc_receive_call: callback XID

00000001, length=20

[56579.837174] RPC: rpcrdma_bc_receive_call: 00 00 00 01 00 00 00

00 00 00 00 00 00 00 00 00 00 00 00 04

After that, rpcrdma_bc_receive_call will meets NULL pointer as,

[ 226.057890] BUG: unable to handle kernel NULL pointer dereference at

00000000000000c8

...

[ 226.058704] RIP: 0010:_raw_spin_lock+0xc/0x20

...

[ 226.059732] Call Trace:

[ 226.059878] rpcrdma_bc_receive_call+0x138/0x327 [rpcrdma]

[ 226.060011] __ib_process_cq+0x89/0x170 [ib_core]

[ 226.060092] ib_cq_poll_work+0x26/0x80 [ib_core]

[ 226.060257] process_one_work+0x1a7/0x360

[ 226.060367] ? create_worker+0x1a0/0x1a0

[ 226.060440] worker_thread+0x30/0x390

[ 226.060500] ? create_worker+0x1a0/0x1a0

[ 226.060574] kthread+0x116/0x130

[ 226.060661] ? kthread_flush_work_fn+0x10/0x10

[ 226.060724] ret_from_fork+0x35/0x40

...