{"id":"CVE-2026-98372","revision":"de45eb3880134170934eeecdb2e74496","records":[{"revision":"de45eb3880134170934eeecdb2e74496","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98372","aliases":[],"title":"xfrm: iptfs: fix stack OOB read in iptfs_skb_reset_frag_walk()","description":"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.","state":0,"publishedAt":"2026-10-06T08:46:56.529+00:00","modifiedAt":"2026-10-19T09:18:24.195+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/xfrm/xfrm_iptfs.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5f2b6a9095743a6bf1f34c43c4fe78fa8bdf5ad7\",\n                            \"lessThan\": \"7e1c6884a0b494b7e3f204877f94c1e07a117bf7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5f2b6a9095743a6bf1f34c43c4fe78fa8bdf5ad7\",\n                            \"lessThan\": \"da56d0ee93d1bad779b0486f2fab92d1bc1f0cf3\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5f2b6a9095743a6bf1f34c43c4fe78fa8bdf5ad7\",\n                            \"lessThan\": \"d042487dc118e494db2e2c1382310255c90ff544\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/xfrm/xfrm_iptfs.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.14\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.14\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.54\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.8\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/7e1c6884a0b494b7e3f204877f94c1e07a117bf7","https://git.kernel.org/stable/c/da56d0ee93d1bad779b0486f2fab92d1bc1f0cf3","https://git.kernel.org/stable/c/d042487dc118e494db2e2c1382310255c90ff544"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98372","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98372","identifiers":["CVE-2026-98372"]},"retained":false,"historicalAffected":[]}],"coverage":[]}