Bug 2548395 (CVE-2026-98383) - CVE-2026-98383 kernel: bpf: Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL
Summary: CVE-2026-98383 kernel: bpf: Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL
Keywords:
Status: NEW
Alias: CVE-2026-98383
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-10-09 08:01 UTC by OSIDB Bzimport
Modified: 2026-10-10 16:16 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)

Description OSIDB Bzimport 2026-10-09 08:01:45 UTC
In the Linux kernel, the following vulnerability has been resolved:

bpf: Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL

An LWT_SEG6LOCAL program can invalidate its cached SRH with
bpf_lwt_seg6_adjust_srh() and then call bpf_skb_pull_data(). The latter
may reallocate skb->head, leaving the per-CPU SRH pointer dangling.
Post-program SRH validation then writes through that pointer.

Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL programs so the verifier
rejects this unsafe helper combination. Other LWT program types continue
to expose the helper through lwt_out_func_proto().


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