ghsa-gc96-qrrv-3724
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid use-after-free in f2fs_stop_gc_thread()
syzbot reports a f2fs bug as below:
__dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_report+0xe8/0x550 mm/kasan/report.c:491 kasan_report+0x143/0x180 mm/kasan/report.c:601 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline] __refcount_add include/linux/refcount.h:184 [inline] __refcount_inc include/linux/refcount.h:241 [inline] refcount_inc include/linux/refcount.h:258 [inline] get_task_struct include/linux/sched/task.h:118 [inline] kthread_stop+0xca/0x630 kernel/kthread.c:704 f2fs_stop_gc_thread+0x65/0xb0 fs/f2fs/gc.c:210 f2fs_do_shutdown+0x192/0x540 fs/f2fs/file.c:2283 f2fs_ioc_shutdown fs/f2fs/file.c:2325 [inline] __f2fs_ioctl+0x443a/0xbe60 fs/f2fs/file.c:4325 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f
The root cause is below race condition, it may cause use-after-free issue in sbi->gc_th pointer.
- remount
- f2fs_remount
- f2fs_stop_gc_thread
- kfree(gc_th) - f2fs_ioc_shutdown - f2fs_do_shutdown - f2fs_stop_gc_thread - kthread_stop(gc_th->f2fs_gc_task) : sbi->gc_thread = NULL;
We will call f2fs_do_shutdown() in two paths: - for f2fs_ioc_shutdown() path, we should grab sb->s_umount semaphore for fixing. - for f2fs_shutdown() path, it's safe since caller has already grabbed sb->s_umount semaphore.
{
"affected": [],
"aliases": [
"CVE-2024-47691"
],
"database_specific": {
"cwe_ids": [
"CWE-416"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-10-21T12:15:05Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to avoid use-after-free in f2fs_stop_gc_thread()\n\nsyzbot reports a f2fs bug as below:\n\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114\n print_report+0xe8/0x550 mm/kasan/report.c:491\n kasan_report+0x143/0x180 mm/kasan/report.c:601\n kasan_check_range+0x282/0x290 mm/kasan/generic.c:189\n instrument_atomic_read_write include/linux/instrumented.h:96 [inline]\n atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]\n __refcount_add include/linux/refcount.h:184 [inline]\n __refcount_inc include/linux/refcount.h:241 [inline]\n refcount_inc include/linux/refcount.h:258 [inline]\n get_task_struct include/linux/sched/task.h:118 [inline]\n kthread_stop+0xca/0x630 kernel/kthread.c:704\n f2fs_stop_gc_thread+0x65/0xb0 fs/f2fs/gc.c:210\n f2fs_do_shutdown+0x192/0x540 fs/f2fs/file.c:2283\n f2fs_ioc_shutdown fs/f2fs/file.c:2325 [inline]\n __f2fs_ioctl+0x443a/0xbe60 fs/f2fs/file.c:4325\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:907 [inline]\n __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nThe root cause is below race condition, it may cause use-after-free\nissue in sbi-\u003egc_th pointer.\n\n- remount\n - f2fs_remount\n - f2fs_stop_gc_thread\n - kfree(gc_th)\n\t\t\t\t- f2fs_ioc_shutdown\n\t\t\t\t - f2fs_do_shutdown\n\t\t\t\t - f2fs_stop_gc_thread\n\t\t\t\t - kthread_stop(gc_th-\u003ef2fs_gc_task)\n : sbi-\u003egc_thread = NULL;\n\nWe will call f2fs_do_shutdown() in two paths:\n- for f2fs_ioc_shutdown() path, we should grab sb-\u003es_umount semaphore\nfor fixing.\n- for f2fs_shutdown() path, it\u0027s safe since caller has already grabbed\nsb-\u003es_umount semaphore.",
"id": "GHSA-gc96-qrrv-3724",
"modified": "2024-10-23T21:30:27Z",
"published": "2024-10-21T12:30:55Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-47691"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7c339dee7eb0f8e4cadc317c595f898ef04dae30"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c7f114d864ac91515bb07ac271e9824a20f5ed95"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d79343cd66343709e409d96b2abb139a0a55ce34"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/fc18e655b62ac6bc9f12f5de0d749b4a3fe1e812"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
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