ghsa-48mq-8mrg-r5qq
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to invalidate dcc->f2fs_issue_discard in error path
Syzbot reports a NULL pointer dereference issue as below:
__refcount_add include/linux/refcount.h:193 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] get_task_struct include/linux/sched/task.h:110 [inline] kthread_stop+0x34/0x1c0 kernel/kthread.c:703 f2fs_stop_discard_thread+0x3c/0x5c fs/f2fs/segment.c:1638 kill_f2fs_super+0x5c/0x194 fs/f2fs/super.c:4522 deactivate_locked_super+0x70/0xe8 fs/super.c:332 deactivate_super+0xd0/0xd4 fs/super.c:363 cleanup_mnt+0x1f8/0x234 fs/namespace.c:1186 __cleanup_mnt+0x20/0x30 fs/namespace.c:1193 task_work_run+0xc4/0x14c kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x26c/0xbe0 kernel/exit.c:795 do_group_exit+0x60/0xe8 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __wake_up_parent+0x0/0x40 kernel/exit.c:934 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581
The root cause of this issue is in error path of f2fs_start_discard_thread(), it missed to invalidate dcc->f2fs_issue_discard, later kthread_stop() may access invalid pointer.
{
"affected": [],
"aliases": [
"CVE-2022-50620"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-12-08T02:15:47Z",
"severity": null
},
"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.",
"id": "GHSA-48mq-8mrg-r5qq",
"modified": "2025-12-08T03:31:02Z",
"published": "2025-12-08T03:31:02Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-50620"
},
{
"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"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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