CVE-2024-56372

/// Technical description

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

net: tun: fix tun_napi_alloc_frags()

syzbot reported the following crash [1]

Issue came with the blamed commit. Instead of going through

all the iov components, we keep using the first one

and end up with a malformed skb.

[1]

kernel BUG at net/core/skbuff.c:2849 !

Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI

CPU: 0 UID: 0 PID: 6230 Comm: syz-executor132 Not tainted 6.13.0-rc1-syzkaller-00407-g96b6fcc0ee41 #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024

RIP: 0010:__pskb_pull_tail+0x1568/0x1570 net/core/skbuff.c:2848

Code: 38 c1 0f 8c 32 f1 ff ff 4c 89 f7 e8 92 96 74 f8 e9 25 f1 ff ff e8 e8 ae 09 f8 48 8b 5c 24 08 e9 eb fb ff ff e8 d9 ae 09 f8 90 <0f> 0b 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90

RSP: 0018:ffffc90004cbef30 EFLAGS: 00010293

RAX: ffffffff8995c347 RBX: 00000000fffffff2 RCX: ffff88802cf45a00

RDX: 0000000000000000 RSI: 00000000ffffff

/// 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