{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2024-47691",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "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->gc_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->f2fs_gc_task)\n   : sbi->gc_thread = NULL;\n\nWe will call f2fs_do_shutdown() in two paths:\n- for f2fs_ioc_shutdown() path, we should grab sb->s_umount semaphore\nfor fixing.\n- for f2fs_shutdown() path, it's safe since caller has already grabbed\nsb->s_umount semaphore."
            }
        ]
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "n/a"
                    }
                ]
            }
        ]
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "vendor_name": "Linux",
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Linux",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_name": "7950e9ac638e",
                                            "version_value": "fc18e655b62a"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "4.16",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "4.16",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.6.54",
                                                        "lessThanOrEqual": "6.6.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.10.13",
                                                        "lessThanOrEqual": "6.10.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.11.2",
                                                        "lessThanOrEqual": "6.11.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.12-rc1",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
                                            }
                                        }
                                    ]
                                }
                            }
                        ]
                    }
                }
            ]
        }
    },
    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/fc18e655b62ac6bc9f12f5de0d749b4a3fe1e812",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/fc18e655b62ac6bc9f12f5de0d749b4a3fe1e812"
            },
            {
                "url": "https://git.kernel.org/stable/c/7c339dee7eb0f8e4cadc317c595f898ef04dae30",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/7c339dee7eb0f8e4cadc317c595f898ef04dae30"
            },
            {
                "url": "https://git.kernel.org/stable/c/d79343cd66343709e409d96b2abb139a0a55ce34",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/d79343cd66343709e409d96b2abb139a0a55ce34"
            },
            {
                "url": "https://git.kernel.org/stable/c/c7f114d864ac91515bb07ac271e9824a20f5ed95",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/c7f114d864ac91515bb07ac271e9824a20f5ed95"
            }
        ]
    },
    "generator": {
        "engine": "bippy-c9c4e1df01b2"
    }
}