{"id":"CVE-2026-31533","title":"net/tls: fix use-after-free in -EBUSY error path of tls_do_encryption","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tls: fix use-after-free in -EBUSY error path of tls_do_encryption\n\nThe -EBUSY handling in tls_do_encryption(), introduced by commit\n859054147318 (\"net: tls: handle …","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 3ade391adc584f17b5570fd205de3ad029090368 < 414fc5e5a5aff776c150f1b86770e0a25a35df3a","Linux >= cd1bbca03f3c1d845ce274c0d0a66de8e5929f72 < 02f3ecadb23558bbe068e6504118f1b712d4ece0","Linux >= 13eca403876bbea3716e82cdfe6f1e6febb38754 < 0e43e0a3c94044acc74b8e0927c27972eb5a59e8","Linux >= 8590541473188741055d27b955db0777569438e3 < aa9facde6c5005205874c37db3fd25799d741baf","Linux >= 8590541473188741055d27b955db0777569438e3 < 5d70eb25b41e9b010828cd12818b06a0c3b04412","Linux >= 8590541473188741055d27b955db0777569438e3 < 2694d408b0e595024e0fc1d64ff9db0358580f74","Linux >= 8590541473188741055d27b955db0777569438e3 < a9b8b18364fffce4c451e6f6fd218fa4ab646705","Linux ab6397f072e5097f267abf5cb08a8004e6b17694","Linux >= 5.15.160 < 5.15.203","Linux >= 6.1.84 < 6.1.169","Linux >= 6.6.18 < 6.6.135","Linux >= 6.7.6 < 6.8","Linux 6.8"],"published":"2026-04-23","updated":"2026-09-08","sourceUpdated":"2026-09-08T08:47:40.390Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31533","references":[{"url":"https://git.kernel.org/stable/c/414fc5e5a5aff776c150f1b86770e0a25a35df3a"},{"url":"https://git.kernel.org/stable/c/02f3ecadb23558bbe068e6504118f1b712d4ece0"},{"url":"https://git.kernel.org/stable/c/0e43e0a3c94044acc74b8e0927c27972eb5a59e8"},{"url":"https://git.kernel.org/stable/c/aa9facde6c5005205874c37db3fd25799d741baf"},{"url":"https://git.kernel.org/stable/c/5d70eb25b41e9b010828cd12818b06a0c3b04412"},{"url":"https://git.kernel.org/stable/c/2694d408b0e595024e0fc1d64ff9db0358580f74"},{"url":"https://git.kernel.org/stable/c/a9b8b18364fffce4c451e6f6fd218fa4ab646705"}],"tags":["cve.org"],"epss":0.00388,"epssPercentile":0.32798,"ingestedAt":"2026-09-08T15:33:26.990Z","slug":"CVE-2026-31533","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/tls: fix use-after-free in -EBUSY error path of tls_do_encryption\n\nThe -EBUSY handling in tls_do_encryption(), introduced by commit\n859054147318 (\"net: tls: handle backlogging of crypto requests\"), has\na use-after-free due to double cleanup of encrypt_pending and the\nscatterlist entry.\n\nWhen crypto_aead_encrypt() returns -EBUSY, the request is enqueued to\nthe cryptd backlog and the async callback tls_encrypt_done() will be\ninvoked upon completion. That callback unconditionally restores the\nscatterlist entry (sge->offset, sge->length) and decrements\nctx->encrypt_pending. However, if tls_encrypt_async_wait() returns an\nerror, the synchronous error path in tls_do_encryption() performs the\nsame cleanup again, double-decrementing encrypt_pending and\ndouble-restoring the scatterlist.\n\nThe double-decrement corrupts the encrypt_pending sentinel (initialized\nto 1), making tls_encrypt_async_wait() permanently skip the wait for\npending async callbacks. A subsequent sendmsg can then free the\ntls_rec via bpf_exec_tx_verdict() while a cryptd callback is still\npending, resulting in a use-after-free when the callback fires on the\nfreed record.\n\nFix this by skipping the synchronous cleanup when the -EBUSY async\nwait returns an error, since the callback has already handled\nencrypt_pending and sge restoration.\n\n## Affected\n\n- `Linux >= 3ade391adc584f17b5570fd205de3ad029090368 < 414fc5e5a5aff776c150f1b86770e0a25a35df3a`\n- `Linux >= cd1bbca03f3c1d845ce274c0d0a66de8e5929f72 < 02f3ecadb23558bbe068e6504118f1b712d4ece0`\n- `Linux >= 13eca403876bbea3716e82cdfe6f1e6febb38754 < 0e43e0a3c94044acc74b8e0927c27972eb5a59e8`\n- `Linux >= 8590541473188741055d27b955db0777569438e3 < aa9facde6c5005205874c37db3fd25799d741baf`\n- `Linux >= 8590541473188741055d27b955db0777569438e3 < 5d70eb25b41e9b010828cd12818b06a0c3b04412`\n- `Linux >= 8590541473188741055d27b955db0777569438e3 < 2694d408b0e595024e0fc1d64ff9db0358580f74`\n- `Linux >= 8590541473188741055d27b955db0777569438e3 < a9b8b18364fffce4c451e6f6fd218fa4ab646705`\n- `Linux ab6397f072e5097f267abf5cb08a8004e6b17694`\n- `Linux >= 5.15.160 < 5.15.203`\n- `Linux >= 6.1.84 < 6.1.169`\n- `Linux >= 6.6.18 < 6.6.135`\n- `Linux >= 6.7.6 < 6.8`\n- `Linux 6.8`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}