{"id":"CVE-2025-22030","summary":"mm: zswap: fix crypto_free_acomp() deadlock in zswap_cpu_comp_dead()","details":"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-\u003eacomp_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-\u003eacomp_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-\u003eacomp_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.","modified":"2026-04-02T12:45:19.826570Z","published":"2025-04-16T14:11:50.625Z","related":["SUSE-SU-2025:01919-1","SUSE-SU-2025:01951-1","SUSE-SU-2025:01964-1","SUSE-SU-2025:01965-1","SUSE-SU-2025:01967-1","SUSE-SU-2025:01972-1","SUSE-SU-2025:02000-1","SUSE-SU-2025:20408-1","SUSE-SU-2025:20413-1","SUSE-SU-2025:20419-1","SUSE-SU-2025:20421-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/22xxx/CVE-2025-22030.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/717d9c35deff6c33235693171bacbb03e9643fa4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/747e3eec1d7d124ea90ed3d7b85369df8b4e36d2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a8d18000e9d2d97aaf105f5f9b3b0e8a6fbf8b96"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c11bcbc0a517acf69282c8225059b2a8ac5fe628"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/22xxx/CVE-2025-22030.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-22030"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"8d29ff5d50304daa41dc3cfdda4a9d1e46cf5be1"},{"fixed":"747e3eec1d7d124ea90ed3d7b85369df8b4e36d2"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"12dcb0ef540629a281533f9dedc1b6b8e14cfb65"},{"fixed":"a8d18000e9d2d97aaf105f5f9b3b0e8a6fbf8b96"},{"fixed":"717d9c35deff6c33235693171bacbb03e9643fa4"},{"fixed":"c11bcbc0a517acf69282c8225059b2a8ac5fe628"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-22030.json"}}],"schema_version":"1.7.5"}