CVE-2022-48925

/// Technical description

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

RDMA/cma: Do not change route.addr.src_addr outside state checks

If the state is not idle then resolve_prepare_src() should immediately

fail and no change to global state should happen. However, it

unconditionally overwrites the src_addr trying to build a temporary any

address.

For instance if the state is already RDMA_CM_LISTEN then this will corrupt

the src_addr and would cause the test in cma_cancel_operation():

if (cma_any_addr(cma_src_addr(id_priv)) && !id_priv->cma_dev)

Which would manifest as this trace from syzkaller:

BUG: KASAN: use-after-free in __list_add_valid+0x93/0xa0 lib/list_debug.c:26

Read of size 8 at addr ffff8881546491e0 by task syz-executor.1/32204

CPU: 1 PID: 32204 Comm: syz-executor.1 Not tainted 5.12.0-rc8-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Call Trace:

__dump_stack lib/dump_stack.c:79 [inline]

d

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References