{"id":"CVE-2025-22030","state":"PUBLISHED","title":"mm: zswap: fix crypto_free_acomp() deadlock in zswap_cpu_comp_dead()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm: zswap: fix crypto_free_acomp() deadlock in zswap_cpu_comp_dead()\n\nCurrently, zswap_cpu_comp_dead() calls crypto_free_acomp() while holding\nthe per-CPU acomp_ctx mutex.  crypto_free_acomp() then holds scomp_lock\n(through crypto_exit_scomp_ops_async()).\n\nOn the other hand, crypto_alloc_acomp_node() holds the scomp_lock (through\ncrypto_scomp_init_tfm()), and then allocates memory.  If the allocation\nresults in reclaim, we may attempt to hold the per-CPU acomp_ctx mutex.\n\nThe above dependencies can cause an ABBA deadlock.  For example in the\nfollowing scenario:\n\n(1) Task A running on CPU #1:\n    crypto_alloc_acomp_node()\n      Holds scomp_lock\n      Enters reclaim\n      Reads per_cpu_ptr(pool->acomp_ctx, 1)\n\n(2) Task A is descheduled\n\n(3) CPU #1 goes offline\n    zswap_cpu_comp_dead(CPU #1)\n      Holds per_cpu_ptr(pool->acomp_ctx, 1))\n      Calls crypto_free_acomp()\n      Waits for scomp_lock\n\n(4) Task A running on CPU #2:\n      Waits for per_cpu_ptr(pool->acomp_ctx, 1) // Read on CPU #1\n      DEADLOCK\n\nSince there is no requirement to call crypto_free_acomp() with the per-CPU\nacomp_ctx mutex held in zswap_cpu_comp_dead(), move it after the mutex is\nunlocked.  Also move the acomp_request_free() and kfree() calls for\nconsistency and to avoid any potential sublte locking dependencies in the\nfuture.\n\nWith this, only setting acomp_ctx fields to NULL occurs with the mutex\nheld.  This is similar to how zswap_cpu_comp_prepare() only initializes\nacomp_ctx fields with the mutex held, after performing all allocations\nbefore holding the mutex.\n\nOpportunistically, move the NULL check on acomp_ctx so that it takes place\nbefore the mutex dereference.","publishedAt":"2025-04-16T14:11:50.625Z","updatedAt":"2026-05-23T15:57:40.079Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8d29ff5d50304daa41dc3cfdda4a9d1e46cf5be1","status":"affected","lessThan":"747e3eec1d7d124ea90ed3d7b85369df8b4e36d2","versionType":"git"},{"version":"12dcb0ef540629a281533f9dedc1b6b8e14cfb65","status":"affected","lessThan":"a8d18000e9d2d97aaf105f5f9b3b0e8a6fbf8b96","versionType":"git"},{"version":"12dcb0ef540629a281533f9dedc1b6b8e14cfb65","status":"affected","lessThan":"717d9c35deff6c33235693171bacbb03e9643fa4","versionType":"git"},{"version":"12dcb0ef540629a281533f9dedc1b6b8e14cfb65","status":"affected","lessThan":"c11bcbc0a517acf69282c8225059b2a8ac5fe628","versionType":"git"},{"version":"6.12.12","status":"affected","lessThan":"6.12.23","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/zswap.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.13","versionType":"semver"},{"version":"6.12.23","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.13.11","status":"unaffected","lessThanOrEqual":"6.13.*","versionType":"semver"},{"version":"6.14.2","status":"unaffected","lessThanOrEqual":"6.14.*","versionType":"semver"},{"version":"6.15","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/zswap.c"]}],"references":["https://git.kernel.org/stable/c/747e3eec1d7d124ea90ed3d7b85369df8b4e36d2","https://git.kernel.org/stable/c/a8d18000e9d2d97aaf105f5f9b3b0e8a6fbf8b96","https://git.kernel.org/stable/c/717d9c35deff6c33235693171bacbb03e9643fa4","https://git.kernel.org/stable/c/c11bcbc0a517acf69282c8225059b2a8ac5fe628"],"weaknesses":[],"ingestedAt":"2026-10-29T20:08:39.238Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/22xxx/CVE-2025-22030.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-22030","state":"PUBLISHED","datePublished":"2025-04-16T14:11:50.625Z","dateUpdated":"2026-05-23T15:57:40.079Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-12-29T08:45:45.808Z"},"containers":{"cna":{"title":"mm: zswap: fix crypto_free_acomp() deadlock in zswap_cpu_comp_dead()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm: zswap: fix crypto_free_acomp() deadlock in zswap_cpu_comp_dead()\n\nCurrently, zswap_cpu_comp_dead() calls crypto_free_acomp() while holding\nthe per-CPU acomp_ctx mutex.  crypto_free_acomp() then holds scomp_lock\n(through crypto_exit_scomp_ops_async()).\n\nOn the other hand, crypto_alloc_acomp_node() holds the scomp_lock (through\ncrypto_scomp_init_tfm()), and then allocates memory.  If the allocation\nresults in reclaim, we may attempt to hold the per-CPU acomp_ctx mutex.\n\nThe above dependencies can cause an ABBA deadlock.  For example in the\nfollowing scenario:\n\n(1) Task A running on CPU #1:\n    crypto_alloc_acomp_node()\n      Holds scomp_lock\n      Enters reclaim\n      Reads per_cpu_ptr(pool->acomp_ctx, 1)\n\n(2) Task A is descheduled\n\n(3) CPU #1 goes offline\n    zswap_cpu_comp_dead(CPU #1)\n      Holds per_cpu_ptr(pool->acomp_ctx, 1))\n      Calls crypto_free_acomp()\n      Waits for scomp_lock\n\n(4) Task A running on CPU #2:\n      Waits for per_cpu_ptr(pool->acomp_ctx, 1) // Read on CPU #1\n      DEADLOCK\n\nSince there is no requirement to call crypto_free_acomp() with the per-CPU\nacomp_ctx mutex held in zswap_cpu_comp_dead(), move it after the mutex is\nunlocked.  Also move the acomp_request_free() and kfree() calls for\nconsistency and to avoid any potential sublte locking dependencies in the\nfuture.\n\nWith this, only setting acomp_ctx fields to NULL occurs with the mutex\nheld.  This is similar to how zswap_cpu_comp_prepare() only initializes\nacomp_ctx fields with the mutex held, after performing all allocations\nbefore holding the mutex.\n\nOpportunistically, move the NULL check on acomp_ctx so that it takes place\nbefore the mutex dereference."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8d29ff5d50304daa41dc3cfdda4a9d1e46cf5be1","status":"affected","lessThan":"747e3eec1d7d124ea90ed3d7b85369df8b4e36d2","versionType":"git"},{"version":"12dcb0ef540629a281533f9dedc1b6b8e14cfb65","status":"affected","lessThan":"a8d18000e9d2d97aaf105f5f9b3b0e8a6fbf8b96","versionType":"git"},{"version":"12dcb0ef540629a281533f9dedc1b6b8e14cfb65","status":"affected","lessThan":"717d9c35deff6c33235693171bacbb03e9643fa4","versionType":"git"},{"version":"12dcb0ef540629a281533f9dedc1b6b8e14cfb65","status":"affected","lessThan":"c11bcbc0a517acf69282c8225059b2a8ac5fe628","versionType":"git"},{"version":"6.12.12","status":"affected","lessThan":"6.12.23","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/zswap.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.13","versionType":"semver"},{"version":"6.12.23","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.13.11","status":"unaffected","lessThanOrEqual":"6.13.*","versionType":"semver"},{"version":"6.14.2","status":"unaffected","lessThanOrEqual":"6.14.*","versionType":"semver"},{"version":"6.15","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/zswap.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/747e3eec1d7d124ea90ed3d7b85369df8b4e36d2"},{"url":"https://git.kernel.org/stable/c/a8d18000e9d2d97aaf105f5f9b3b0e8a6fbf8b96"},{"url":"https://git.kernel.org/stable/c/717d9c35deff6c33235693171bacbb03e9643fa4"},{"url":"https://git.kernel.org/stable/c/c11bcbc0a517acf69282c8225059b2a8ac5fe628"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-23T15:57:40.079Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.12","versionEndExcluding":"6.12.23"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.13.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.14.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.15"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}