CVE-2026-98372
In 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:
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
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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.:
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.
Detalles técnicos trazas, registros y código del informe original
while (offset >= walk->past + walk->frags[walk->fragi].len) walk->past += walk->frags[walk->fragi++].len; if (!walk->nr_frags || offset >= walk->total + walk->initial_offset) return len; 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
CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
FIRST aún no ha puntuado esta CVE (habitual en CVEs muy recientes o rechazadas).
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
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{
"id": "CVE-2026-98372",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5f2b6a9095743a6bf1f34c43c4fe78fa8bdf5ad7",
"lessThan": "7e1c6884a0b494b7e3f204877f94c1e07a117bf7",
"versionType": "git"
},
{
"status": "affected",
"version": "5f2b6a9095743a6bf1f34c43c4fe78fa8bdf5ad7",
"lessThan": "da56d0ee93d1bad779b0486f2fab92d1bc1f0cf3",
"versionType": "git"
},
{
"status": "affected",
"version": "5f2b6a9095743a6bf1f34c43c4fe78fa8bdf5ad7",
"lessThan": "d042487dc118e494db2e2c1382310255c90ff544",
"versionType": "git"
}
],
"programFiles": [
"net/xfrm/xfrm_iptfs.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.14"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.14",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.54",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.8",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3-rc4",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/xfrm/xfrm_iptfs.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-06T09:18:31.743",
"references": [
{
"url": "https://git.kernel.org/stable/c/7e1c6884a0b494b7e3f204877f94c1e07a117bf7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/d042487dc118e494db2e2c1382310255c90ff544",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/da56d0ee93d1bad779b0486f2fab92d1bc1f0cf3",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: fix stack OOB read in iptfs_skb_reset_frag_walk()\n\niptfs_skb_reset_frag_walk() advances to the fragment containing @offset\nwith an unbounded loop:\n\n\twhile (offset >= walk->past + walk->frags[walk->fragi].len)\n\t\twalk->past += walk->frags[walk->fragi++].len;\n\nwalk->fragi is advanced and walk->frags[walk->fragi] is dereferenced\nwithout ever checking fragi against walk->nr_frags. When the requested\noffset is at or beyond the total length spanned by the walk's fragments,\nfragi runs past nr_frags and off the end of the fixed-size on-stack\nfrags[MAX_SKB_FRAGS + 1] array, reading out-of-bounds stack memory.\n\nThe two callers behave differently: iptfs_skb_add_frags() already guards\nagainst this with\n\n\tif (!walk->nr_frags ||\n\t offset >= walk->total + walk->initial_offset)\n\t\treturn len;\n\nbut iptfs_skb_can_add_frags() has no such guard and calls\niptfs_skb_reset_frag_walk() unconditionally, so it performs the\nout-of-range walk. Its own \"fragi < walk->nr_frags\" bound check runs only\nafterwards, too late to prevent the read.\n\nThis is reachable from the receive path: a crafted IP-TFS (AGGFRAG)\npayload delivered to an IPTFS SA drives iptfs_reassem_cont() ->\niptfs_skb_can_add_frags() with an offset past the fragment total, e.g.:\n\n BUG: KASAN: stack-out-of-bounds in iptfs_skb_reset_frag_walk+0x235/0x250\n Read of size 4 at addr ffff888008ad7210 by task repro/345\n iptfs_skb_reset_frag_walk+0x235/0x250 net/xfrm/xfrm_iptfs.c:392\n iptfs_skb_can_add_frags+0x155/0x310 net/xfrm/xfrm_iptfs.c:420\n iptfs_reassem_cont+0xcf8/0x1140 net/xfrm/xfrm_iptfs.c:902\n iptfs_input_ordered+0x552/0x670 net/xfrm/xfrm_iptfs.c:1280\n iptfs_input+0x3d6/0xde0 net/xfrm/xfrm_iptfs.c:1741\n xfrm_input+0x282f/0x6140 net/xfrm/xfrm_input.c:700\n xfrm4_esp_rcv+0x93/0x120 net/ipv4/xfrm4_protocol.c:104\n ip_rcv+0x278/0x2d0 net/ipv4/ip_input.c:612\n\nGive iptfs_skb_can_add_frags() the same up-front guard that\niptfs_skb_add_frags() already has, so the walk is never entered with an\nout-of-range offset. When it triggers, the caller falls back to the\nexisting linearize-and-copy path, which is safe."
}
],
"lastModified": "2026-10-06T09:18:31.743",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}