Out-of-bounds Read Affecting kernel-rt-modules-extra package, versions <0:4.18.0-553.22.1.rt7.363.el8_10

Note: Versions mentioned in the description apply only to the upstream kernel-rt-modules-extra package and not the kernel-rt-modules-extra package as distributed by Centos. See How to fix? for Centos:8 relevant fixed versions and status.

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

tunnels: fix out of bounds access when building IPv6 PMTU error

If the ICMPv6 error is built from a non-linear skb we get the following splat,

BUG: KASAN: slab-out-of-bounds in do_csum+0x220/0x240 Read of size 4 at addr ffff88811d402c80 by task netperf/820 CPU: 0 PID: 820 Comm: netperf Not tainted 6.8.0-rc1+ #543 ... kasan_report+0xd8/0x110 do_csum+0x220/0x240 csum_partial+0xc/0x20 skb_tunnel_check_pmtu+0xeb9/0x3280 vxlan_xmit_one+0x14c2/0x4080 vxlan_xmit+0xf61/0x5c00 dev_hard_start_xmit+0xfb/0x510 __dev_queue_xmit+0x7cd/0x32a0 br_dev_queue_push_xmit+0x39d/0x6a0

Use skb_checksum instead of csum_partial who cannot deal with non-linear SKBs.

• https://access.redhat.com/security/cve/CVE-2024-26665
• https://git.kernel.org/stable/c/510c869ffa4068c5f19ff4df51d1e2f3a30aaac1
• https://git.kernel.org/stable/c/7dc9feb8b1705cf00de20563b6bc4831f4c99dab
• https://git.kernel.org/stable/c/d75abeec401f8c86b470e7028a13fcdc87e5dd06
• https://git.kernel.org/stable/c/d964dd1bc1452594b4207d9229c157d9386e5d8a
• https://git.kernel.org/stable/c/e37cde7a5716466ff2a76f7f27f0a29b05b9a732
• https://git.kernel.org/stable/c/e77bf828f1ca1c47fcff58bdc26b60a9d3dfbe1d
• https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html