Bug 1222328 (CVE-2024-26665)

Summary: VUL-0: CVE-2024-26665: kernel: tunnels: fix out of bounds access when building IPv6 PMTU error
Product: [Novell Products] SUSE Security Incidents Reporter: SMASH SMASH <smash_bz>
Component: IncidentsAssignee: Security Team bot <security-team>
Status: NEW --- QA Contact: Security Team bot <security-team>
Severity: Normal    
Priority: P3 - Medium CC: camila.matos, mhocko, mkoutny, nik.borisov, rfrohl
Version: unspecified   
Target Milestone: ---   
Hardware: Other   
OS: Other   
URL: https://smash.suse.de/issue/399973/
Whiteboard: CVSSv3.1:SUSE:CVE-2024-26665:5.5:(AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Found By: Security Response Team Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---

Description SMASH SMASH 2024-04-04 14:51:03 UTC 
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.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-26665
https://www.cve.org/CVERecord?id=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://bugzilla.redhat.com/show_bug.cgi?id=2272793
Comment 5 Nikolay Borisov 2024-07-10 09:23:10 UTC 
Backports pushed to SLE15-SP[56]. Since the CVESS rating is 5.5, which is lower than 7, LTSS aren't eligible to get the backport so I conside this as fixed.