{"id":"AZL-63929","summary":"CVE-2025-38052 affecting package kernel for versions less than 6.6.96.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tipc: fix slab-use-after-free Read in tipc_aead_encrypt_done\n\nSyzbot reported a slab-use-after-free with the following call trace:\n\n  ==================================================================\n  BUG: KASAN: slab-use-after-free in tipc_aead_encrypt_done+0x4bd/0x510 net/tipc/crypto.c:840\n  Read of size 8 at addr ffff88807a733000 by task kworker/1:0/25\n\n  Call Trace:\n   kasan_report+0xd9/0x110 mm/kasan/report.c:601\n   tipc_aead_encrypt_done+0x4bd/0x510 net/tipc/crypto.c:840\n   crypto_request_complete include/crypto/algapi.h:266\n   aead_request_complete include/crypto/internal/aead.h:85\n   cryptd_aead_crypt+0x3b8/0x750 crypto/cryptd.c:772\n   crypto_request_complete include/crypto/algapi.h:266\n   cryptd_queue_worker+0x131/0x200 crypto/cryptd.c:181\n   process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231\n\n  Allocated by task 8355:\n   kzalloc_noprof include/linux/slab.h:778\n   tipc_crypto_start+0xcc/0x9e0 net/tipc/crypto.c:1466\n   tipc_init_net+0x2dd/0x430 net/tipc/core.c:72\n   ops_init+0xb9/0x650 net/core/net_namespace.c:139\n   setup_net+0x435/0xb40 net/core/net_namespace.c:343\n   copy_net_ns+0x2f0/0x670 net/core/net_namespace.c:508\n   create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110\n   unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:228\n   ksys_unshare+0x419/0x970 kernel/fork.c:3323\n   __do_sys_unshare kernel/fork.c:3394\n\n  Freed by task 63:\n   kfree+0x12a/0x3b0 mm/slub.c:4557\n   tipc_crypto_stop+0x23c/0x500 net/tipc/crypto.c:1539\n   tipc_exit_net+0x8c/0x110 net/tipc/core.c:119\n   ops_exit_list+0xb0/0x180 net/core/net_namespace.c:173\n   cleanup_net+0x5b7/0xbf0 net/core/net_namespace.c:640\n   process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231\n\nAfter freed the tipc_crypto tx by delete namespace, tipc_aead_encrypt_done\nmay still visit it in cryptd_queue_worker workqueue.\n\nI reproduce this issue by:\n  ip netns add ns1\n  ip link add veth1 type veth peer name veth2\n  ip link set veth1 netns ns1\n  ip netns exec ns1 tipc bearer enable media eth dev veth1\n  ip netns exec ns1 tipc node set key this_is_a_master_key master\n  ip netns exec ns1 tipc bearer disable media eth dev veth1\n  ip netns del ns1\n\nThe key of reproduction is that, simd_aead_encrypt is interrupted, leading\nto crypto_simd_usable() return false. Thus, the cryptd_queue_worker is\ntriggered, and the tipc_crypto tx will be visited.\n\n  tipc_disc_timeout\n    tipc_bearer_xmit_skb\n      tipc_crypto_xmit\n        tipc_aead_encrypt\n          crypto_aead_encrypt\n            // encrypt()\n            simd_aead_encrypt\n              // crypto_simd_usable() is false\n              child = &ctx-\u003ecryptd_tfm-\u003ebase;\n\n  simd_aead_encrypt\n    crypto_aead_encrypt\n      // encrypt()\n      cryptd_aead_encrypt_enqueue\n        cryptd_aead_enqueue\n          cryptd_enqueue_request\n            // trigger cryptd_queue_worker\n            queue_work_on(smp_processor_id(), cryptd_wq, &cpu_queue-\u003ework)\n\nFix this by holding net reference count before encrypt.","modified":"2026-04-01T05:20:13.560765Z","published":"2025-06-18T10:15:37Z","upstream":["CVE-2025-38052"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38052"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.96.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-63929.json"}}],"schema_version":"1.7.5"}