xfrm: iptfs: fix stack OOB read in iptfs_skb_reset_frag_walk()

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-98372
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-06 09:18:31 UTC
Updated2026-10-06 09:18:31 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: xfrm: iptfs: fix stack OOB read in iptfs_skb_reset_frag_walk() iptfs_skb_reset_frag_walk() advances to the fragment containing @offset with an unbounded loop: while (offset >= walk->past + walk->frags[walk->fragi].len) walk->past += walk->frags[walk->fragi++].len; walk->fragi is advanced and walk->frags[walk->fragi] is dereferenced without ever checking fragi against walk->nr_frags. When the requested offset is at or beyond the total length spanned by the walk's fragments, fragi runs past nr_frags and off the end of the fixed-size on-stack frags[MAX_SKB_FRAGS + 1] array, reading out-of-bounds stack memory. The two callers behave differently: iptfs_skb_add_frags() already guards against this with if (!walk->nr_frags || offset >= walk->total + walk->initial_offset) return len; but iptfs_skb_can_add_frags() has no such guard and calls iptfs_skb_reset_frag_walk() unconditionally, so it performs the out-of-range walk. Its own "fragi < walk->nr_frags" bound check runs only afterwards, too late to prevent the read. This is reachable from the receive path: a crafted IP-TFS (AGGFRAG) payload delivered to an IPTFS SA drives iptfs_reassem_cont() -> iptfs_skb_can_add_frags() with an offset past the fragment total, e.g.: BUG: KASAN: stack-out-of-bounds in iptfs_skb_reset_frag_walk+0x235/0x250 Read of size 4 at addr ffff888008ad7210 by task repro/345 iptfs_skb_reset_frag_walk+0x235/0x250 net/xfrm/xfrm_iptfs.c:392 iptfs_skb_can_add_frags+0x155/0x310 net/xfrm/xfrm_iptfs.c:420 iptfs_reassem_cont+0xcf8/0x1140 net/xfrm/xfrm_iptfs.c:902 iptfs_input_ordered+0x552/0x670 net/xfrm/xfrm_iptfs.c:1280 iptfs_input+0x3d6/0xde0 net/xfrm/xfrm_iptfs.c:1741 xfrm_input+0x282f/0x6140 net/xfrm/xfrm_input.c:700 xfrm4_esp_rcv+0x93/0x120 net/ipv4/xfrm4_protocol.c:104 ip_rcv+0x278/0x2d0 net/ipv4/ip_input.c:612 Give iptfs_skb_can_add_frags() the same up-front guard that iptfs_skb_add_frags() already has, so the walk is never entered with an out-of-range offset. When it triggers, the caller falls back to the existing linearize-and-copy path, which is safe.

Risk And Classification

EPSS: 0.001610000 probability, percentile 0.047050000 (date 2026-10-06)

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 5f2b6a9095743a6bf1f34c43c4fe78fa8bdf5ad7 7e1c6884a0b494b7e3f204877f94c1e07a117bf7 git Not specified
CNA Linux Linux affected 5f2b6a9095743a6bf1f34c43c4fe78fa8bdf5ad7 da56d0ee93d1bad779b0486f2fab92d1bc1f0cf3 git Not specified
CNA Linux Linux affected 5f2b6a9095743a6bf1f34c43c4fe78fa8bdf5ad7 d042487dc118e494db2e2c1382310255c90ff544 git Not specified
CNA Linux Linux affected 6.14 Not specified
CNA Linux Linux unaffected 6.14 semver Not specified
CNA Linux Linux unaffected 6.18.54 6.18.* semver Not specified
CNA Linux Linux unaffected 7.2.8 7.2.* semver Not specified
CNA Linux Linux unaffected 7.3-rc4 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/d042487dc118e494db2e2c1382310255c90ff544 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/da56d0ee93d1bad779b0486f2fab92d1bc1f0cf3 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/7e1c6884a0b494b7e3f204877f94c1e07a117bf7 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report