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CVE-2026-89783

xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, and 2 more
None on Exploit-DB, Metasploit or GitHub

Summary

The Linux kernel's IPv6 IPsec (xfrm6) input path is affected, specifically the code that handles destination-options and routing-header processing for transport-mode packets. An off-by-one depth check can let a crafted packet write one slot past a fixed-size array, which can crash systems that have UBSAN with panic-on-warn enabled.

Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.

Read the original description

In the Linux kernel, the following vulnerability has been resolved: xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full The depth check in xfrm6_input_addr() is off by one: if (1 + sp->len == XFRM_MAX_DEPTH) goto drop; ... sp->xvec[sp->len++] = x; xfrm_input() can leave sp->len == XFRM_MAX_DEPTH, and the transport-mode receive path re-enters IPv6 input via xfrm_trans_reinject() with that secpath preserved. If the inner packet carries a destination-options HAO option or a type-2 routing header, xfrm6_input_addr() is called with sp->len == XFRM_MAX_DEPTH; the check (1 + 6 == 6) is false, so sp->xvec[sp->len++] writes one slot past the 6-element xvec[]. The write stays within the sec_path allocation (invisible to KASAN); UBSAN_BOUNDS flags it and panics under panic_on_warn. Use "sp->len >= XFRM_MAX_DEPTH", matching xfrm_input(). This also restores one chain level the old check rejected at sp->len == 5. UBSAN: array-index-out-of-bounds in net/ipv6/xfrm6_input.c:309:10 index 6 is out of range for type 'xfrm_state *[6]'

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Linux Linux

    From 9473e1f631de339c50bde1e3bd09e1045fe90fd5 · fixed in 91fc387f63c00ddfb5221127a17bac97549a8343; From 9473e1f631de339c50bde1e3bd09e1045fe90fd5 · fixed in 68e8737fe8e72f085c608cff322b3d2de8340af1; From 9473e1f631de339c50bde1e3bd09e1045fe90fd5 · fixed in 8fe2c53fb81f5ad5be43af2ad09583f7c78b4b77; From 9473e1f631de339c50bde1e3bd09e1045fe90fd5 · fixed in bdcda866c89f9a8b1acdabf02d26cde9fbe501d8; From 9473e1f631de339c50bde1e3bd09e1045fe90fd5 · fixed in 48996649222e95008cdb98cd58579e3fc8e5ee06; From 9473e1f631de339c50bde1e3bd09e1045fe90fd5 · fixed in 0f679e0523ddfff3fb554336ceb874b0e51e9cd3; From 9473e1f631de339c50bde1e3bd09e1045fe90fd5 · fixed in 5f35a29a5eed3d80befd32050843ac88dea3d61a; From 9473e1f631de339c50bde1e3bd09e1045fe90fd5 · fixed in 5d9e3bf34fec9a5d237e4b7cef4a707bc2e091bc

  • Linux Linux

    2.6.25

  • KernelLinux

    From 2.6.25 · fixed in 5.10.270; From 5.11.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6

References 8

git.kernel.org