{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-53494","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-10-01T11:39:39.403Z","datePublished":"2025-10-01T11:45:45.773Z","dateUpdated":"2026-08-05T09:14:26.466Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T09:14:26.466Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: xts - Handle EBUSY correctly\n\nAs it is xts only handles the special return value of EINPROGRESS,\nwhich means that in all other cases it will free data related to the\nrequest.\n\nHowever, as the caller of xts may specify MAY_BACKLOG, we also need\nto expect EBUSY and treat it in the same way.  Otherwise backlogged\nrequests will trigger a use-after-free."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The only practical trigger for the XTS ciphertext-stealing path with CRYPTO_TFM_REQ_MAY_BACKLOG is the local AF_ALG socket interface (crypto/algif_skcipher.c), reached via socket()/bind()/sendmsg()/recvmsg(); no in-kernel network consumer uses XTS with unaligned lengths.\nAC:L - The attacker controls every precondition: they choose the async XTS instantiation by name, choose a cryptlen that is not a multiple of 16 to force the CTS path, and saturate the child driver's backlog queue themselves (crypto_engine default depth is 10, cryptd is per-CPU and can be filled with pinned threads) so the tail request reliably returns -EBUSY.\nPR:L - Opening an AF_ALG socket and binding an arbitrary skcipher template name requires no capabilities, only an unprivileged local account on a kernel with CONFIG_CRYPTO_USER_API_SKCIPHER (standard on distro and Android kernels).\nUI:N - The attacker performs the entire sequence from their own process; no victim action or cooperation is needed.\nS:U - The use-after-free corrupts kernel heap memory within the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - After the request is freed, xts_cts_done() dereferences rctx->tail — a scatterlist pointer read from reclaimed, attacker-sprayable memory — and copies 16 bytes out of it, yielding a controlled kernel-memory read that can be used to disclose arbitrary kernel data.\nI:H - The same forged scatterlist is written back through scatterwalk_map_and_copy(), giving a controlled kernel write, and skcipher_request_complete() then calls req->base.complete — a function pointer taken from freed memory — enabling control-flow hijack and full privilege escalation.\nA:H - Even without successful exploitation the double completion and use-after-free corrupt the crypto request and its owner's socket state, producing KASAN splats, oopses, or a kernel panic."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["crypto/xts.c"],"versions":[{"version":"8083b1bf8163e7ae7d8c90f221106d96450b8aa8","lessThan":"92a07ba4f0af2cccdc2aa5ee32679c9c9714db90","status":"affected","versionType":"git"},{"version":"8083b1bf8163e7ae7d8c90f221106d96450b8aa8","lessThan":"912eb10b65646ffd222256c78a1c566a3dac177d","status":"affected","versionType":"git"},{"version":"8083b1bf8163e7ae7d8c90f221106d96450b8aa8","lessThan":"57c3e1d63b63dc0841d41df729297cd7c1c35808","status":"affected","versionType":"git"},{"version":"8083b1bf8163e7ae7d8c90f221106d96450b8aa8","lessThan":"d5870848879291700fe6c5257dcb48aadd10425c","status":"affected","versionType":"git"},{"version":"8083b1bf8163e7ae7d8c90f221106d96450b8aa8","lessThan":"51c082514c2dedf2711c99d93c196cc4eedceb40","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["crypto/xts.c"],"versions":[{"version":"5.4","status":"affected"},{"version":"0","lessThan":"5.4","status":"unaffected","versionType":"semver"},{"version":"5.10.173","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.99","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.16","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.2.3","lessThanOrEqual":"6.2.*","status":"unaffected","versionType":"semver"},{"version":"6.3","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":"5.4","versionEndExcluding":"5.10.173"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4","versionEndExcluding":"5.15.99"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4","versionEndExcluding":"6.1.16"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4","versionEndExcluding":"6.2.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4","versionEndExcluding":"6.3"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/92a07ba4f0af2cccdc2aa5ee32679c9c9714db90"},{"url":"https://git.kernel.org/stable/c/912eb10b65646ffd222256c78a1c566a3dac177d"},{"url":"https://git.kernel.org/stable/c/57c3e1d63b63dc0841d41df729297cd7c1c35808"},{"url":"https://git.kernel.org/stable/c/d5870848879291700fe6c5257dcb48aadd10425c"},{"url":"https://git.kernel.org/stable/c/51c082514c2dedf2711c99d93c196cc4eedceb40"}],"title":"crypto: xts - Handle EBUSY correctly","x_generator":{"engine":"bippy-1.2.0"}}}}