Bug 2521375 (CVE-2026-74669) - CVE-2026-74669 kernel: ipvs: clear IPv4 options after rebasing tunnel ICMP errors
Summary: CVE-2026-74669 kernel: ipvs: clear IPv4 options after rebasing tunnel ICMP er...
Keywords:
Status: NEW
Alias: CVE-2026-74669
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-22 15:42 UTC by OSIDB Bzimport
Modified: 2026-08-24 09:10 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-08-22 15:42:26 UTC
In the Linux kernel, the following vulnerability has been resolved:

ipvs: clear IPv4 options after rebasing tunnel ICMP errors

ip_vs_in_icmp() rebases an skb from the outer ICMP packet to the
quoted original request before passing it to icmp_send(). However,
IPCB(skb)->opt still describes the outer IPv4 header.

A timestamp option in the outer header can therefore leave an offset
that points into the quoted transport header after the rebase.
__ip_options_echo() treats a byte at that stale location as the option
length and copies it into the fixed-size option storage on the
__icmp_send() stack, causing a stack out-of-bounds write.

Clear the stale option metadata after resetting the network header.
Keep the remaining control block fields, including the ingress
interface used by the ICMP response path.


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