From: Doruk Tan Ozturk <doruk@0sec.ai> stable inclusion from stable-v5.10.260 commit 171d31245d11bf84836fad3b394cb465a4d008ec category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16132 CVE: CVE-2026-63801 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit bda3348872a2ef0d19f2df6aa8cb5025adce2f20 upstream. 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). Fixes: fc1b6d6de220 ("tipc: introduce TIPC encryption & authentication") Cc: stable@vger.kernel.org Signed-off-by: Doruk Tan Ozturk <doruk@0sec.ai> Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com> Reviewed-by: Tung Nguyen <tung.quang.nguyen@est.tech> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20260617075818.37431-1-doruk@0sec.ai Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> --- net/tipc/crypto.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/net/tipc/crypto.c b/net/tipc/crypto.c index 86dbc4ddc1dc..5e8dd0693b8b 100644 --- a/net/tipc/crypto.c +++ b/net/tipc/crypto.c @@ -954,12 +954,20 @@ static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead, goto exit; } + /* Get net to avoid freed tipc_crypto when delete namespace */ + if (!maybe_get_net(net)) { + tipc_bearer_put(b); + rc = -ENODEV; + goto exit; + } + /* Now, do decrypt */ rc = crypto_aead_decrypt(req); if (rc == -EINPROGRESS || rc == -EBUSY) return rc; tipc_bearer_put(b); + put_net(net); exit: kfree(ctx); @@ -997,6 +1005,7 @@ static void tipc_aead_decrypt_done(struct crypto_async_request *base, int err) } tipc_bearer_put(b); + put_net(net); } static inline int tipc_ehdr_size(struct tipc_ehdr *ehdr) -- 2.43.0