CVE-2022-50817

/// Technical description

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

net: hsr: avoid possible NULL deref in skb_clone()

syzbot got a crash [1] in skb_clone(), caused by a bug

in hsr_get_untagged_frame().

When/if create_stripped_skb_hsr() returns NULL, we must

not attempt to call skb_clone().

While we are at it, replace a WARN_ONCE() by netdev_warn_once().

[1]

general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] PREEMPT SMP KASAN

KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f]

CPU: 1 PID: 754 Comm: syz-executor.0 Not tainted 6.0.0-syzkaller-02734-g0326074ff465 #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022

RIP: 0010:skb_clone+0x108/0x3c0 net/core/skbuff.c:1641

Code: 93 02 00 00 49 83 7c 24 28 00 0f 85 e9 00 00 00 e8 5d 4a 29 fa 4c 8d 75 7e 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <0f> b6 04 02 4c 89 f2 83 e2 07 38 d0 7f 08 84 c0 0f 85 9e 01 00 00

RSP: 0018:ffffc90003c

/// 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