{"id":"CVE-2022-50620","summary":"f2fs: fix to invalidate dcc-\u003ef2fs_issue_discard in error path","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to invalidate dcc-\u003ef2fs_issue_discard in error path\n\nSyzbot reports a NULL pointer dereference issue as below:\n\n __refcount_add include/linux/refcount.h:193 [inline]\n __refcount_inc include/linux/refcount.h:250 [inline]\n refcount_inc include/linux/refcount.h:267 [inline]\n get_task_struct include/linux/sched/task.h:110 [inline]\n kthread_stop+0x34/0x1c0 kernel/kthread.c:703\n f2fs_stop_discard_thread+0x3c/0x5c fs/f2fs/segment.c:1638\n kill_f2fs_super+0x5c/0x194 fs/f2fs/super.c:4522\n deactivate_locked_super+0x70/0xe8 fs/super.c:332\n deactivate_super+0xd0/0xd4 fs/super.c:363\n cleanup_mnt+0x1f8/0x234 fs/namespace.c:1186\n __cleanup_mnt+0x20/0x30 fs/namespace.c:1193\n task_work_run+0xc4/0x14c kernel/task_work.c:177\n exit_task_work include/linux/task_work.h:38 [inline]\n do_exit+0x26c/0xbe0 kernel/exit.c:795\n do_group_exit+0x60/0xe8 kernel/exit.c:925\n __do_sys_exit_group kernel/exit.c:936 [inline]\n __se_sys_exit_group kernel/exit.c:934 [inline]\n __wake_up_parent+0x0/0x40 kernel/exit.c:934\n __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]\n invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]\n el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142\n do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206\n el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636\n el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654\n el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581\n\nThe root cause of this issue is in error path of f2fs_start_discard_thread(),\nit missed to invalidate dcc-\u003ef2fs_issue_discard, later kthread_stop() may\naccess invalid pointer.","modified":"2026-04-02T08:28:39.210800Z","published":"2025-12-08T01:16:33.771Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/50xxx/CVE-2022-50620.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/865bb7b5a7deeb0e5afbd82381d52d38825dc64d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/91586ce0d39a05f88795aa8814fb99b1387236b3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a3e517a6ba695d683ee63615e1ea6e6b4c7d2732"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ae6c960a82c52c3bda5adc82d90643d6c12d308e"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/50xxx/CVE-2022-50620.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-50620"},{"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":"4d67490498acb4ffcef5ba7bc44990d46e66a44c"},{"fixed":"865bb7b5a7deeb0e5afbd82381d52d38825dc64d"},{"fixed":"a3e517a6ba695d683ee63615e1ea6e6b4c7d2732"},{"fixed":"ae6c960a82c52c3bda5adc82d90643d6c12d308e"},{"fixed":"91586ce0d39a05f88795aa8814fb99b1387236b3"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-50620.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.15.0"},{"fixed":"5.15.86"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.0.16"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.1.0"},{"fixed":"6.1.2"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-50620.json"}}],"schema_version":"1.7.5"}