bpf: Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL

Summary

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().

Timeline

1. Oct 9, 2026, 7:34 AM UTCCVE published
2. Oct 24, 2026, 2:08 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 004d4b274e2a1a895a0e5dc66158b90a7d463d44 · fixed in 0f38472a2aa8704a6b514c0dfa9c32f3672b8f32; From 004d4b274e2a1a895a0e5dc66158b90a7d463d44 · fixed in cae8674489f26edf7553fdd660599466cbb4c32f; From 004d4b274e2a1a895a0e5dc66158b90a7d463d44 · fixed in 9f9e57b5a3a033f95f49ef9d541340cdbcb80abb; From 004d4b274e2a1a895a0e5dc66158b90a7d463d44 · fixed in df0072be6fc373cb22f9ea854d458b04e32a03cf; From 004d4b274e2a1a895a0e5dc66158b90a7d463d44 · fixed in b9bb0e735460751b620156f800a4279a28573392; From 004d4b274e2a1a895a0e5dc66158b90a7d463d44 · fixed in 37b18688cd18fd86d2f35c212df1611862a26cd5; From 004d4b274e2a1a895a0e5dc66158b90a7d463d44 · fixed in fca71ead7a20290af1e2046983eeafae43d21af1; From 004d4b274e2a1a895a0e5dc66158b90a7d463d44 · fixed in e4a62833adff6ef0fe7c0b90393204fe3c26b5c5

• Linux Linux

  4.18

• KernelLinux

  From 4.18.0 · fixed in 5.10.271; From 5.11.0 · fixed in 5.15.222; From 5.16.0 · fixed in 6.1.189; From 6.2.0 · fixed in 6.6.158; From 6.7.0 · fixed in 6.12.112; From 6.13.0 · fixed in 6.18.55; From 6.19.0 · fixed in 7.2.9

References 8