GHSA-XQWJ-PHVH-5PP9
Vulnerability from github – Published: 2026-07-19 12:30 – Updated: 2026-07-20 15:31In the Linux kernel, the following vulnerability has been resolved:
tipc: fix slab-use-after-free Read in tipc_aead_decrypt_done
tipc_aead_decrypt() goes straight from tipc_bearer_hold(b) to crypto_aead_decrypt(req) without taking a reference on the netns, unlike the encrypt path. When crypto_aead_decrypt() is offloaded asynchronously (e.g. the SIMD aead wrapper queuing to cryptd), the cryptd worker runs tipc_aead_decrypt_done() later. If the bearer's netns is torn down in the meantime, cleanup_net() -> tipc_exit_net() -> tipc_crypto_stop() frees the per-netns tipc_crypto, and the completion then reads it: tipc_aead_decrypt_done() dereferences aead->crypto->stats and aead->crypto->net, and tipc_crypto_rcv_complete() dereferences aead->crypto->aead[] and the node table -- reading freed memory.
Decoded KASAN splat (v7.1-rc7, CONFIG_KASAN_INLINE + TIPC + TIPC_CRYPTO):
BUG: KASAN: slab-use-after-free in tipc_aead_decrypt_done (net/tipc/crypto.c:999) Read of size 8 at addr ffff8881056258a8 by task kworker/u16:2/51 Workqueue: events_unbound Call Trace: tipc_aead_decrypt_done (net/tipc/crypto.c:999) process_one_work (kernel/workqueue.c:3314) worker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:158) ret_from_fork_asm (arch/x86/entry/entry_64.S:245)
Allocated by task 169: __kasan_kmalloc (mm/kasan/common.c:398 mm/kasan/common.c:415) tipc_crypto_start (net/tipc/crypto.c:1502) tipc_init_net (net/tipc/core.c:72) ops_init (net/core/net_namespace.c:137) setup_net (net/core/net_namespace.c:446) copy_net_ns (net/core/net_namespace.c:579) create_new_namespaces (kernel/nsproxy.c:132) __x64_sys_unshare (kernel/fork.c:3316) do_syscall_64 (arch/x86/entry/syscall_64.c:63) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
Freed by task 8: kfree (mm/slub.c:6566) tipc_exit_net (net/tipc/core.c:119) cleanup_net (net/core/net_namespace.c:704) process_one_work (kernel/workqueue.c:3314) kthread (kernel/kthread.c:436)
This is the same class of bug that commit e279024617134 ("net/tipc: fix slab-use-after-free Read in tipc_aead_encrypt_done") fixed for the encrypt side. The encrypt path takes maybe_get_net(aead->crypto->net) before crypto_aead_encrypt() and drops it with put_net() on the synchronous return paths and in tipc_aead_encrypt_done(); the -EINPROGRESS/-EBUSY return keeps the reference for the async callback to release. The decrypt path was left without the equivalent guard.
Mirror the encrypt-side fix on the decrypt path: take a net reference before crypto_aead_decrypt() (failing with -ENODEV and the matching bearer put if it cannot be acquired), keep it across the -EINPROGRESS/-EBUSY async return, and drop it with put_net() on the synchronous success/error return and at the end of tipc_aead_decrypt_done().
Reproduced under KASAN on v7.1-rc7: a UDP bearer with a cluster key is flooded with crafted encrypted frames from an unknown peer (driving the cluster-key decrypt path) while the bearer's netns is repeatedly torn down. The completion must run asynchronously to outlive tipc_crypto_stop(); on x86 the stock aesni gcm(aes) now decrypts synchronously, so the async path was exercised via cryptd offload. The unguarded aead->crypto dereference in tipc_aead_decrypt_done() is the unpatched upstream path; tipc_aead_decrypt() still lacks maybe_get_net(aead->crypto->net), so the completion can outlive the free on any config where crypto_aead_decrypt() goes async.
Found by 0sec automated security-research tooling (https://0sec.ai).
{
"affected": [],
"aliases": [
"CVE-2026-63801"
],
"database_specific": {
"cwe_ids": [
"CWE-416"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-19T12:16:52Z",
"severity": "HIGH"
},
"details": "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\u0027s netns is torn down in the\nmeantime, cleanup_net() -\u003e tipc_exit_net() -\u003e tipc_crypto_stop() frees the\nper-netns tipc_crypto, and the completion then reads it:\ntipc_aead_decrypt_done() dereferences aead-\u003ecrypto-\u003estats and\naead-\u003ecrypto-\u003enet, and tipc_crypto_rcv_complete() dereferences\naead-\u003ecrypto-\u003eaead[] 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-\u003ecrypto-\u003enet) 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\u0027s 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-\u003ecrypto dereference in tipc_aead_decrypt_done() is the\nunpatched upstream path; tipc_aead_decrypt() still lacks\nmaybe_get_net(aead-\u003ecrypto-\u003enet), 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).",
"id": "GHSA-xqwj-phvh-5pp9",
"modified": "2026-07-20T15:31:47Z",
"published": "2026-07-19T12:30:23Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63801"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0a780653b2a7569a7af9be7d0b00b1251baca63a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/171d31245d11bf84836fad3b394cb465a4d008ec"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1eea5e1820a2f5164d706bd1277bc97ff31ce32d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2d1f21419ec121232c916d3a3fc9b6766473a0e7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bda3348872a2ef0d19f2df6aa8cb5025adce2f20"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dca7713fe044a2067387948557ea099056e1679e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e18769616fd5a90ec1e12aabbba544c488284292"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/eaca7dae02fab70c8d223cffe03cec1b93249ce2"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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