{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-46116", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.098Z", "datePublished": "2026-05-28T09:35:30.689Z", "dateUpdated": "2026-05-28T09:35:30.689Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-28T09:35:30.689Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: defensively unhash xfrm_state lists in __xfrm_state_delete\n\nKASAN reproduces a slab-use-after-free in __xfrm_state_delete()'s\nhlist_del_rcu calls under syzkaller load on linux-6.12.y stable\n(reproduced on 6.12.47, also reachable via the same code path on\ntorvalds/master and on the ipsec tree). Nine unique signatures cluster\nin the xfrm_state lifecycle, the load-bearing one being:\n\n BUG: KASAN: slab-use-after-free in __hlist_del include/linux/list.h:990 [inline]\n BUG: KASAN: slab-use-after-free in hlist_del_rcu include/linux/rculist.h:516 [inline]\n BUG: KASAN: slab-use-after-free in __xfrm_state_delete net/xfrm/xfrm_state.c\n Write of size 8 at addr ffff8881198bcb70 by task kworker/u8:9/435\n\n Workqueue: netns cleanup_net\n Call Trace:\n __hlist_del / hlist_del_rcu\n __xfrm_state_delete\n xfrm_state_delete\n xfrm_state_flush\n xfrm_state_fini\n ops_exit_list\n cleanup_net\n\nThe other observed signatures hit the same slab object from\n__xfrm_state_lookup, xfrm_alloc_spi, __xfrm_state_insert and an OOB\nwrite variant of __xfrm_state_delete, all on the byseq/byspi\nhash chains.\n\n__xfrm_state_delete() guards its byseq and byspi unhashes with\nvalue-based predicates:\n\n\tif (x->km.seq)\n\t\thlist_del_rcu(&x->byseq);\n\tif (x->id.spi)\n\t\thlist_del_rcu(&x->byspi);\n\nwhile everywhere else in the file (e.g. state_cache, state_cache_input)\nthe safer hlist_unhashed() check is used. xfrm_alloc_spi() sets\nx->id.spi = newspi inside xfrm_state_lock and then immediately inserts\ninto byspi, but a path that observes x->id.spi != 0 outside of\nxfrm_state_lock can still skip-or-hit the byspi unhash inconsistently\nwith whether x is actually on the list. The same holds for x->km.seq\nversus byseq, and the bydst/bysrc unhashes have no predicate at all,\nso a second __xfrm_state_delete() on the same object writes through\nLIST_POISON pprev.\n\nThe defensive change here:\n\n - Use hlist_del_init_rcu() instead of hlist_del_rcu() on bydst,\n bysrc, byseq and byspi so a second deletion is a no-op rather\n than a write through LIST_POISON pprev. The byseq/byspi nodes\n are already initialised in xfrm_state_alloc().\n - Test hlist_unhashed() rather than the value predicate for\n byseq/byspi, so the unhash decision tracks list state rather than\n mutable scalar fields.\n\nEmpirical verification: applied this patch on top of v6.12.47, rebuilt,\nand re-ran the same syzkaller harness for 1h16m on a previously-crashy\nconfiguration that produced ~100 hits each of slab-use-after-free\nRead in xfrm_alloc_spi / Read in __xfrm_state_lookup / Write in\n__xfrm_state_delete. After the patch, 7.1M execs across 32 VMs at\n~1550 exec/sec produced zero xfrm_state UAF/OOB hits. /proc/slabinfo\nconfirms the xfrm_state slab is actively allocated and freed during\nthe run (~143 KiB resident), so the fuzzer is still exercising those\ncode paths -- they just no longer crash.\n\nReproduction:\n\n - Linux 6.12.47 x86_64 + KASAN_GENERIC + KASAN_INLINE + KCOV\n - syzkaller @ 746545b8b1e4c3a128db8652b340d3df90ce61db\n - 32 QEMU/KVM VMs x 2 vCPU on AWS c5.metal bare metal\n - 9 unique signatures collected in ~9h, all within xfrm_state\n lifecycle"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/xfrm/xfrm_state.c"], "versions": [{"version": "7b4dc3600e4877178ba94c7fbf7e520421378aa6", "lessThan": "b4a53add2fa8f1b5aa17d4c5686c320785fab182", "status": "affected", "versionType": "git"}, {"version": "7b4dc3600e4877178ba94c7fbf7e520421378aa6", "lessThan": "26edb0a3c99f9d958c212be68b21f1221614dcf0", "status": "affected", "versionType": "git"}, {"version": "7b4dc3600e4877178ba94c7fbf7e520421378aa6", "lessThan": "4980162de555cb838f1a189ce7d2cbf5d2e7b050", "status": "affected", "versionType": "git"}, {"version": "7b4dc3600e4877178ba94c7fbf7e520421378aa6", "lessThan": "a2e2d08fb070fab4947447171f1c4e3ca5a188e5", "status": "affected", "versionType": "git"}, {"version": "7b4dc3600e4877178ba94c7fbf7e520421378aa6", "lessThan": "14acf9652e5690de3c7486c6db5fb8dafd0a32a3", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/xfrm/xfrm_state.c"], "versions": [{"version": "2.6.19", "status": "affected"}, {"version": "0", "lessThan": "2.6.19", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.140", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.88", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.30", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.7", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1-rc3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "6.6.140"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "6.12.88"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "6.18.30"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "7.0.7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "7.1-rc3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/b4a53add2fa8f1b5aa17d4c5686c320785fab182"}, {"url": "https://git.kernel.org/stable/c/26edb0a3c99f9d958c212be68b21f1221614dcf0"}, {"url": "https://git.kernel.org/stable/c/4980162de555cb838f1a189ce7d2cbf5d2e7b050"}, {"url": "https://git.kernel.org/stable/c/a2e2d08fb070fab4947447171f1c4e3ca5a188e5"}, {"url": "https://git.kernel.org/stable/c/14acf9652e5690de3c7486c6db5fb8dafd0a32a3"}], "title": "xfrm: defensively unhash xfrm_state lists in __xfrm_state_delete", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: defensively unhash xfrm_state lists in __xfrm_state_delete\n\nKASAN reproduces a slab-use-after-free in __xfrm_state_delete()'s\nhlist_del_rcu calls under syzkaller load on linux-6.12.y stable\n(reproduced on 6.12.47, also reachable via the same code path on\ntorvalds/master and on the ipsec tree). Nine unique signatures cluster\nin the xfrm_state lifecycle, the load-bearing one being:\n\n BUG: KASAN: slab-use-after-free in __hlist_del include/linux/list.h:990 [inline]\n BUG: KASAN: slab-use-after-free in hlist_del_rcu include/linux/rculist.h:516 [inline]\n BUG: KASAN: slab-use-after-free in __xfrm_state_delete net/xfrm/xfrm_state.c\n Write of size 8 at addr ffff8881198bcb70 by task kworker/u8:9/435\n\n Workqueue: netns cleanup_net\n Call Trace:\n __hlist_del / hlist_del_rcu\n __xfrm_state_delete\n xfrm_state_delete\n xfrm_state_flush\n xfrm_state_fini\n ops_exit_list\n cleanup_net\n\nThe other observed signatures hit the same slab object from\n__xfrm_state_lookup, xfrm_alloc_spi, __xfrm_state_insert and an OOB\nwrite variant of __xfrm_state_delete, all on the byseq/byspi\nhash chains.\n\n__xfrm_state_delete() guards its byseq and byspi unhashes with\nvalue-based predicates:\n\n\tif (x->km.seq)\n\t\thlist_del_rcu(&x->byseq);\n\tif (x->id.spi)\n\t\thlist_del_rcu(&x->byspi);\n\nwhile everywhere else in the file (e.g. state_cache, state_cache_input)\nthe safer hlist_unhashed() check is used. xfrm_alloc_spi() sets\nx->id.spi = newspi inside xfrm_state_lock and then immediately inserts\ninto byspi, but a path that observes x->id.spi != 0 outside of\nxfrm_state_lock can still skip-or-hit the byspi unhash inconsistently\nwith whether x is actually on the list. The same holds for x->km.seq\nversus byseq, and the bydst/bysrc unhashes have no predicate at all,\nso a second __xfrm_state_delete() on the same object writes through\nLIST_POISON pprev.\n\nThe defensive change here:\n\n - Use hlist_del_init_rcu() instead of hlist_del_rcu() on bydst,\n bysrc, byseq and byspi so a second deletion is a no-op rather\n than a write through LIST_POISON pprev. The byseq/byspi nodes\n are already initialised in xfrm_state_alloc().\n - Test hlist_unhashed() rather than the value predicate for\n byseq/byspi, so the unhash decision tracks list state rather than\n mutable scalar fields.\n\nEmpirical verification: applied this patch on top of v6.12.47, rebuilt,\nand re-ran the same syzkaller harness for 1h16m on a previously-crashy\nconfiguration that produced ~100 hits each of slab-use-after-free\nRead in xfrm_alloc_spi / Read in __xfrm_state_lookup / Write in\n__xfrm_state_delete. After the patch, 7.1M execs across 32 VMs at\n~1550 exec/sec produced zero xfrm_state UAF/OOB hits. /proc/slabinfo\nconfirms the xfrm_state slab is actively allocated and freed during\nthe run (~143 KiB resident), so the fuzzer is still exercising those\ncode paths -- they just no longer crash.\n\nReproduction:\n\n - Linux 6.12.47 x86_64 + KASAN_GENERIC + KASAN_INLINE + KCOV\n - syzkaller @ 746545b8b1e4c3a128db8652b340d3df90ce61db\n - 32 QEMU/KVM VMs x 2 vCPU on AWS c5.metal bare metal\n - 9 unique signatures collected in ~9h, all within xfrm_state\n lifecycle"}], "id": "CVE-2026-46116", "lastModified": "2026-05-28T13:44:01.663", "metrics": {}, "published": "2026-05-28T10:16:27.080", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/14acf9652e5690de3c7486c6db5fb8dafd0a32a3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/26edb0a3c99f9d958c212be68b21f1221614dcf0"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4980162de555cb838f1a189ce7d2cbf5d2e7b050"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a2e2d08fb070fab4947447171f1c4e3ca5a188e5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b4a53add2fa8f1b5aa17d4c5686c320785fab182"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7b4dc3600e4877178ba94c7fbf7e520421378aa6,b4a53add2fa8f1b5aa17d4c5686c320785fab182)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7b4dc3600e4877178ba94c7fbf7e520421378aa6,26edb0a3c99f9d958c212be68b21f1221614dcf0)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7b4dc3600e4877178ba94c7fbf7e520421378aa6,4980162de555cb838f1a189ce7d2cbf5d2e7b050)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7b4dc3600e4877178ba94c7fbf7e520421378aa6,a2e2d08fb070fab4947447171f1c4e3ca5a188e5)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7b4dc3600e4877178ba94c7fbf7e520421378aa6,14acf9652e5690de3c7486c6db5fb8dafd0a32a3)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "2.6.19"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,2.6.19)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.140,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.88,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.30,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.0.7,7.1.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1-rc3,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-05-28T11:30:15.486309+00:00", "updated": "2026-05-28T12:15:19.719560+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-416"]}