{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-63801", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.013Z", "datePublished": "2026-07-19T12:02:07.457Z", "dateUpdated": "2026-08-17T04:51:06.693Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:51:06.693Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: fix slab-use-after-free Read in tipc_aead_decrypt_done\n\ntipc_aead_decrypt() goes straight from tipc_bearer_hold(b) to\ncrypto_aead_decrypt(req) without taking a reference on the netns, unlike\nthe encrypt path. When crypto_aead_decrypt() is offloaded asynchronously\n(e.g. the SIMD aead wrapper queuing to cryptd), the cryptd worker runs\ntipc_aead_decrypt_done() later. If the bearer's netns is torn down in the\nmeantime, cleanup_net() -> tipc_exit_net() -> tipc_crypto_stop() frees the\nper-netns tipc_crypto, and the completion then reads it:\ntipc_aead_decrypt_done() dereferences aead->crypto->stats and\naead->crypto->net, and tipc_crypto_rcv_complete() dereferences\naead->crypto->aead[] and the node table -- reading freed memory.\n\nDecoded KASAN splat (v7.1-rc7, CONFIG_KASAN_INLINE + TIPC + TIPC_CRYPTO):\n\n BUG: KASAN: slab-use-after-free in tipc_aead_decrypt_done (net/tipc/crypto.c:999)\n Read of size 8 at addr ffff8881056258a8 by task kworker/u16:2/51\n Workqueue: events_unbound\n Call Trace:\n tipc_aead_decrypt_done (net/tipc/crypto.c:999)\n process_one_work (kernel/workqueue.c:3314)\n worker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478)\n kthread (kernel/kthread.c:436)\n ret_from_fork (arch/x86/kernel/process.c:158)\n ret_from_fork_asm (arch/x86/entry/entry_64.S:245)\n\n Allocated by task 169:\n __kasan_kmalloc (mm/kasan/common.c:398 mm/kasan/common.c:415)\n tipc_crypto_start (net/tipc/crypto.c:1502)\n tipc_init_net (net/tipc/core.c:72)\n ops_init (net/core/net_namespace.c:137)\n setup_net (net/core/net_namespace.c:446)\n copy_net_ns (net/core/net_namespace.c:579)\n create_new_namespaces (kernel/nsproxy.c:132)\n __x64_sys_unshare (kernel/fork.c:3316)\n do_syscall_64 (arch/x86/entry/syscall_64.c:63)\n entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n\n Freed by task 8:\n kfree (mm/slub.c:6566)\n tipc_exit_net (net/tipc/core.c:119)\n cleanup_net (net/core/net_namespace.c:704)\n process_one_work (kernel/workqueue.c:3314)\n kthread (kernel/kthread.c:436)\n\nThis is the same class of bug that commit e279024617134 (\"net/tipc: fix\nslab-use-after-free Read in tipc_aead_encrypt_done\") fixed for the encrypt\nside. The encrypt path takes maybe_get_net(aead->crypto->net) before\ncrypto_aead_encrypt() and drops it with put_net() on the synchronous\nreturn paths and in tipc_aead_encrypt_done(); the -EINPROGRESS/-EBUSY\nreturn keeps the reference for the async callback to release. The decrypt\npath was left without the equivalent guard.\n\nMirror the encrypt-side fix on the decrypt path: take a net reference\nbefore crypto_aead_decrypt() (failing with -ENODEV and the matching\nbearer put if it cannot be acquired), keep it across the\n-EINPROGRESS/-EBUSY async return, and drop it with put_net() on the\nsynchronous success/error return and at the end of\ntipc_aead_decrypt_done().\n\nReproduced under KASAN on v7.1-rc7: a UDP bearer with a cluster key is\nflooded with crafted encrypted frames from an unknown peer (driving the\ncluster-key decrypt path) while the bearer's netns is repeatedly torn\ndown. The completion must run asynchronously to outlive\ntipc_crypto_stop(); on x86 the stock aesni gcm(aes) now decrypts\nsynchronously, so the async path was exercised via cryptd offload. The\nunguarded aead->crypto dereference in tipc_aead_decrypt_done() is the\nunpatched upstream path; tipc_aead_decrypt() still lacks\nmaybe_get_net(aead->crypto->net), so the completion can outlive the free\non any config where crypto_aead_decrypt() goes async.\n\nFound by 0sec automated security-research tooling (https://0sec.ai)." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable code is reached from the TIPC packet receive path (UDP bearer on port 6118 or L2 bearer) when encrypted frames arrive from a remote peer; no local syscall is required to enter tipc_aead_decrypt().\nAC:L - The attacker can reliably win the race by flooding packets to queue async decrypt completions while repeatedly destroying the network namespace; the repro demonstrates full control of both sides of the timing window.\nPR:L - Reliable exploitation is demonstrated via unshare-created user/network namespaces where the attacker gains CAP_NET_ADMIN-equivalent control to configure TIPC crypto and cycle namespace teardown, which per kernel CNA guidance maps to Low rather than High.\nUI:N - Exploitation requires only sending network packets and namespace lifecycle manipulation; no victim user action such as opening a file or mounting a filesystem is needed.\nS:U - Impact is confined to kernel memory within the same security authority; this is a standard kernel UAF/privilege-escalation class bug, not a VM escape or cross-authority boundary bypass.\nC:H - The UAF reads freed slab memory including aead->crypto->stats, aead->crypto->net, and aead[] pointers in tipc_crypto_rcv_complete, enabling arbitrary kernel memory disclosure via controlled reuse of the freed tipc_crypto object.\nI:H - Use-after-free of tipc_crypto structures can be leveraged for heap spraying and arbitrary write primitives, and tipc_crypto_rcv_complete continues processing with freed pointers including key attachment and node table operations.\nA:H - KASAN confirmed slab-use-after-free in tipc_aead_decrypt_done on a workqueue thread; UAF on this path causes kernel oops/panic even when not fully exploited for code execution." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/tipc/crypto.c" ], "versions": [ { "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0", "lessThan": "171d31245d11bf84836fad3b394cb465a4d008ec", "status": "affected", "versionType": "git" }, { "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0", "lessThan": "2d1f21419ec121232c916d3a3fc9b6766473a0e7", "status": "affected", "versionType": "git" }, { "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0", "lessThan": "0a780653b2a7569a7af9be7d0b00b1251baca63a", "status": "affected", "versionType": "git" }, { "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0", "lessThan": "eaca7dae02fab70c8d223cffe03cec1b93249ce2", "status": "affected", "versionType": "git" }, { "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0", "lessThan": "dca7713fe044a2067387948557ea099056e1679e", "status": "affected", "versionType": "git" }, { "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0", "lessThan": "e18769616fd5a90ec1e12aabbba544c488284292", "status": "affected", "versionType": "git" }, { "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0", "lessThan": "1eea5e1820a2f5164d706bd1277bc97ff31ce32d", "status": "affected", "versionType": "git" }, { "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0", "lessThan": "bda3348872a2ef0d19f2df6aa8cb5025adce2f20", "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/tipc/crypto.c" ], "versions": [ { "version": "5.5", "status": "affected" }, { "version": "0", "lessThan": "5.5", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.260", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.211", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.177", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.144", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.95", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.38", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.3", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "5.5", "versionEndExcluding": "5.10.260" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "5.15.211" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.1.177" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.6.144" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.12.95" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.18.38" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "7.1.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/171d31245d11bf84836fad3b394cb465a4d008ec" }, { "url": "https://git.kernel.org/stable/c/2d1f21419ec121232c916d3a3fc9b6766473a0e7" }, { "url": "https://git.kernel.org/stable/c/0a780653b2a7569a7af9be7d0b00b1251baca63a" }, { "url": "https://git.kernel.org/stable/c/eaca7dae02fab70c8d223cffe03cec1b93249ce2" }, { "url": "https://git.kernel.org/stable/c/dca7713fe044a2067387948557ea099056e1679e" }, { "url": "https://git.kernel.org/stable/c/e18769616fd5a90ec1e12aabbba544c488284292" }, { "url": "https://git.kernel.org/stable/c/1eea5e1820a2f5164d706bd1277bc97ff31ce32d" }, { "url": "https://git.kernel.org/stable/c/bda3348872a2ef0d19f2df6aa8cb5025adce2f20" } ], "title": "tipc: fix slab-use-after-free Read in tipc_aead_decrypt_done", "x_generator": { "engine": "bippy-1.2.0" } } } }