{"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"}}}}