{"id":"CVE-2026-90198","summary":"ALSA: core: Fix use-after-free in snd_card_do_free()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: core: Fix use-after-free in snd_card_do_free()\n\nA use-after-free was detected in snd_card_do_free() when a sound card\nmanaged by devres is unbound while a user-space application still holds an\nopen file descriptor.\n\nFor managed cards, the memory is allocated using devres_alloc(), and its\nrelease function is set to __snd_card_release(), which calls\nsnd_card_free(). When the device is unbound, the unbind thread calls\nsnd_card_free(), which drops a reference to the card's device. If the user\nthread still has an open file descriptor, the reference count does not\nreach zero, and the unbind thread blocks on wait_for_completion(&released).\n\nWhen the user thread closes the file descriptor, it drops the final\nreference, invoking the device release callback release_card_device(),\nwhich calls snd_card_do_free(). snd_card_do_free() performs cleanup and\ncalls complete(card-\u003erelease_completion). This wakes up the unbind thread,\nwhich returns from snd_card_free() and __snd_card_release(). The devres\ncore then immediately frees the memory block containing the snd_card\nstructure.\n\nMeanwhile, the user thread continues execution in snd_card_do_free() and\nevaluates `if (!card-\u003emanaged)`. It reads the `managed` boolean from the\nsnd_card structure that was just freed by the unbind thread, triggering a\nKASAN use-after-free.\n\nFix this by caching the value of card-\u003emanaged in a local variable before\ncalling complete(). This ensures that the card pointer is not dereferenced\nafter the unbind thread has been woken up and potentially freed the card.\n\nBUG: KASAN: use-after-free in snd_card_do_free sound/core/init.c:604\n[inline]\nBUG: KASAN: use-after-free in release_card_device+0x1ab/0x1b0\nsound/core/init.c:153\nRead of size 1 at addr ffff8881912ec909 by task syz-executor130/5857\n\nCall Trace:\n \u003cTASK\u003e\n dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120\n print_address_description+0x55/0x1e0 mm/kasan/report.c:378\n print_report+0x58/0x70 mm/kasan/report.c:482\n kasan_report+0x117/0x150 mm/kasan/report.c:595\n snd_card_do_free sound/core/init.c:604 [inline]\n release_card_device+0x1ab/0x1b0 sound/core/init.c:153\n device_release+0xc4/0x1f0 drivers/base/core.c:-1\n kobject_cleanup lib/kobject.c:689 [inline]\n kobject_release lib/kobject.c:720 [inline]\n kref_put include/linux/kref.h:65 [inline]\n kobject_put+0x222/0x550 lib/kobject.c:737\n snd_card_file_remove+0x331/0x390 sound/core/init.c:1125\n snd_pcm_release+0x12c/0x160 sound/core/pcm_native.c:2986\n __fput+0x418/0xa50 fs/file_table.c:512\n fput_close_sync+0x11f/0x240 fs/file_table.c:617\n __do_sys_close fs/open.c:1511 [inline]\n __se_sys_close fs/open.c:1496 [inline]\n __x64_sys_close+0x7e/0x110 fs/open.c:1496\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n \u003c/TASK\u003e","modified":"2026-09-19T03:47:25.096336228Z","published":"2026-09-17T16:07:16.923Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90198.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/03c5dabc8f16bc212a5b26d2425c03a55e55a86d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/09b27dd01b98480334c10bf6fb8d41d5fb063a4b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5ae1a690c522fea2900ff56c8c2ace7b059f5e04"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6da22efb5cf490b06ffbca32b10fc8af7654fee0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7d9b5e86775fa97a487da08b9aa76e1674bf8868"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a561012868ae37c28f61fdf658bf6f251bc0e8e8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d3d67f680dbc23a5e5e3d3ecfdbf700465809877"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90198.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90198"},{"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":"e8ad415b7a55cb9a9fbfc04696518d5ea0b609b3"},{"fixed":"d3d67f680dbc23a5e5e3d3ecfdbf700465809877"},{"fixed":"09b27dd01b98480334c10bf6fb8d41d5fb063a4b"},{"fixed":"03c5dabc8f16bc212a5b26d2425c03a55e55a86d"},{"fixed":"6da22efb5cf490b06ffbca32b10fc8af7654fee0"},{"fixed":"a561012868ae37c28f61fdf658bf6f251bc0e8e8"},{"fixed":"7d9b5e86775fa97a487da08b9aa76e1674bf8868"},{"fixed":"5ae1a690c522fea2900ff56c8c2ace7b059f5e04"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90198.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.15.0"},{"fixed":"5.15.221"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.188"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90198.json"}}],"schema_version":"1.9.0"}