CVE-2024-44987

/// Technical description

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

ipv6: prevent UAF in ip6_send_skb()

syzbot reported an UAF in ip6_send_skb() [1]

After ip6_local_out() has returned, we no longer can safely

dereference rt, unless we hold rcu_read_lock().

A similar issue has been fixed in commit

a688caa34beb ("ipv6: take rcu lock in rawv6_send_hdrinc()")

Another potential issue in ip6_finish_output2() is handled in a

separate patch.

[1]

BUG: KASAN: slab-use-after-free in ip6_send_skb+0x18d/0x230 net/ipv6/ip6_output.c:1964

Read of size 8 at addr ffff88806dde4858 by task syz.1.380/6530

CPU: 1 UID: 0 PID: 6530 Comm: syz.1.380 Not tainted 6.11.0-rc3-syzkaller-00306-gdf6cbc62cc9b #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024

Call Trace:

<TASK>

__dump_stack lib/dump_stack.c:93 [inline]

dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119

print_address_description mm/kasan/report.c:377 [inline]

print_report+0x169/0x550 mm/kasan/repor

/// 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