{ "data_version": "4.0", "data_type": "CVE", "data_format": "MITRE", "CVE_data_meta": { "ID": "CVE-2024-49867", "ASSIGNER": "cve@kernel.org", "STATE": "PUBLIC" }, "description": { "description_data": [ { "lang": "eng", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: wait for fixup workers before stopping cleaner kthread during umount\n\nDuring unmount, at close_ctree(), we have the following steps in this order:\n\n1) Park the cleaner kthread - this doesn't destroy the kthread, it basically\n halts its execution (wake ups against it work but do nothing);\n\n2) We stop the cleaner kthread - this results in freeing the respective\n struct task_struct;\n\n3) We call btrfs_stop_all_workers() which waits for any jobs running in all\n the work queues and then free the work queues.\n\nSyzbot reported a case where a fixup worker resulted in a crash when doing\na delayed iput on its inode while attempting to wake up the cleaner at\nbtrfs_add_delayed_iput(), because the task_struct of the cleaner kthread\nwas already freed. This can happen during unmount because we don't wait\nfor any fixup workers still running before we call kthread_stop() against\nthe cleaner kthread, which stops and free all its resources.\n\nFix this by waiting for any fixup workers at close_ctree() before we call\nkthread_stop() against the cleaner and run pending delayed iputs.\n\nThe stack traces reported by syzbot were the following:\n\n BUG: KASAN: slab-use-after-free in __lock_acquire+0x77/0x2050 kernel/locking/lockdep.c:5065\n Read of size 8 at addr ffff8880272a8a18 by task kworker/u8:3/52\n\n CPU: 1 UID: 0 PID: 52 Comm: kworker/u8:3 Not tainted 6.12.0-rc1-syzkaller #0\n Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024\n Workqueue: btrfs-fixup btrfs_work_helper\n Call Trace:\n \n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:377 [inline]\n print_report+0x169/0x550 mm/kasan/report.c:488\n kasan_report+0x143/0x180 mm/kasan/report.c:601\n __lock_acquire+0x77/0x2050 kernel/locking/lockdep.c:5065\n lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825\n __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]\n _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162\n class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline]\n try_to_wake_up+0xb0/0x1480 kernel/sched/core.c:4154\n btrfs_writepage_fixup_worker+0xc16/0xdf0 fs/btrfs/inode.c:2842\n btrfs_work_helper+0x390/0xc50 fs/btrfs/async-thread.c:314\n process_one_work kernel/workqueue.c:3229 [inline]\n process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310\n worker_thread+0x870/0xd30 kernel/workqueue.c:3391\n kthread+0x2f0/0x390 kernel/kthread.c:389\n ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244\n \n\n Allocated by task 2:\n kasan_save_stack mm/kasan/common.c:47 [inline]\n kasan_save_track+0x3f/0x80 mm/kasan/common.c:68\n unpoison_slab_object mm/kasan/common.c:319 [inline]\n __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345\n kasan_slab_alloc include/linux/kasan.h:247 [inline]\n slab_post_alloc_hook mm/slub.c:4086 [inline]\n slab_alloc_node mm/slub.c:4135 [inline]\n kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4187\n alloc_task_struct_node kernel/fork.c:180 [inline]\n dup_task_struct+0x57/0x8c0 kernel/fork.c:1107\n copy_process+0x5d1/0x3d50 kernel/fork.c:2206\n kernel_clone+0x223/0x880 kernel/fork.c:2787\n kernel_thread+0x1bc/0x240 kernel/fork.c:2849\n create_kthread kernel/kthread.c:412 [inline]\n kthreadd+0x60d/0x810 kernel/kthread.c:765\n ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244\n\n Freed by task 61:\n kasan_save_stack mm/kasan/common.c:47 [inline]\n kasan_save_track+0x3f/0x80 mm/kasan/common.c:68\n kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579\n poison_slab_object mm/kasan/common.c:247 [inline]\n __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264\n kasan_slab_free include/linux/kasan.h:230 [inline]\n slab_free_h\n---truncated---" } ] }, "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": "1da177e4c3f4", "version_value": "70b60c8d9b42" }, { "version_value": "not down converted", "x_cve_json_5_version_data": { "versions": [ { "version": "5.10.227", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.15.168", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.1.113", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.6.55", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.10.14", "lessThanOrEqual": "6.10.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.11.3", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.12-rc2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ], "defaultStatus": "affected" } } ] } } ] } } ] } }, "references": { "reference_data": [ { "url": "https://git.kernel.org/stable/c/70b60c8d9b42763d6629e44f448aa5d8ae477d61", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/70b60c8d9b42763d6629e44f448aa5d8ae477d61" }, { "url": "https://git.kernel.org/stable/c/4c98fe0dfa2ae83c4631699695506d8941db4bfe", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/4c98fe0dfa2ae83c4631699695506d8941db4bfe" }, { "url": "https://git.kernel.org/stable/c/9da40aea63f8769f28afb91aea0fac4cf6fbbb65", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/9da40aea63f8769f28afb91aea0fac4cf6fbbb65" }, { "url": "https://git.kernel.org/stable/c/ed87190e9d9c80aad220fb6b0b03a84d22e2c95b", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/ed87190e9d9c80aad220fb6b0b03a84d22e2c95b" }, { "url": "https://git.kernel.org/stable/c/bf0de0f9a0544c11f96f93206da04ab87dcea1f4", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/bf0de0f9a0544c11f96f93206da04ab87dcea1f4" }, { "url": "https://git.kernel.org/stable/c/65d11eb276836d49003a8060cf31fa2284ad1047", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/65d11eb276836d49003a8060cf31fa2284ad1047" }, { "url": "https://git.kernel.org/stable/c/41fd1e94066a815a7ab0a7025359e9b40e4b3576", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/41fd1e94066a815a7ab0a7025359e9b40e4b3576" } ] }, "generator": { "engine": "bippy-c9c4e1df01b2" } }