================================================================== BUG: KASAN: slab-use-after-free in __mutex_lock_common+0x170/0x28f4 kernel/locking/mutex.c:564 Read of size 8 at addr ffff0000c480a130 by task jffs2_gcd_mtd0/6729 CPU: 0 UID: 0 PID: 6729 Comm: jffs2_gcd_mtd0 Not tainted 6.13.0-rc2-syzkaller-00031-g2e7aff49b5da #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:484 (C) __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x198/0x538 mm/kasan/report.c:489 kasan_report+0xd8/0x138 mm/kasan/report.c:602 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 __mutex_lock_common+0x170/0x28f4 kernel/locking/mutex.c:564 __mutex_lock kernel/locking/mutex.c:735 [inline] mutex_lock_interruptible_nested+0x2c/0x38 kernel/locking/mutex.c:809 jffs2_garbage_collect_pass+0xa4/0x1a50 fs/jffs2/gc.c:134 jffs2_garbage_collect_thread+0x410/0x488 fs/jffs2/background.c:155 kthread+0x288/0x310 kernel/kthread.c:389 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862 Allocated by task 6726: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:568 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x2cc/0x428 mm/slub.c:4314 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] jffs2_init_fs_context+0x58/0xc8 fs/jffs2/super.c:314 alloc_fs_context+0x514/0x7a4 fs/fs_context.c:318 fs_context_for_mount+0x34/0x44 fs/fs_context.c:332 do_new_mount+0x14c/0x900 fs/namespace.c:3486 path_mount+0x590/0xe04 fs/namespace.c:3834 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4057 [inline] __se_sys_mount fs/namespace.c:4034 [inline] __arm64_sys_mount+0x4d4/0x5ac fs/namespace.c:4034 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 Freed by task 6619: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_free_info+0x54/0x6c mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x64/0x8c mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2338 [inline] slab_free mm/slub.c:4598 [inline] kfree+0x180/0x478 mm/slub.c:4746 jffs2_kill_sb+0x9c/0xb0 fs/jffs2/super.c:351 deactivate_locked_super+0xc4/0x12c fs/super.c:473 deactivate_super+0xe0/0x100 fs/super.c:506 cleanup_mnt+0x34c/0x3dc fs/namespace.c:1373 __cleanup_mnt+0x20/0x30 fs/namespace.c:1380 task_work_run+0x230/0x2e0 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] do_notify_resume+0x178/0x1f4 arch/arm64/kernel/entry-common.c:151 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline] el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:745 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 The buggy address belongs to the object at ffff0000c480a000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 304 bytes inside of freed 4096-byte region [ffff0000c480a000, ffff0000c480b000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x104808 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x5ffc00000000040(head|node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 05ffc00000000040 ffff0000c0002140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000001f5000000 0000000000000000 head: 05ffc00000000040 ffff0000c0002140 dead000000000100 dead000000000122 head: 0000000000000000 0000000000040004 00000001f5000000 0000000000000000 head: 05ffc00000000003 fffffdffc3120201 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000c480a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000c480a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000c480a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000c480a180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000c480a200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== jffs2: Erase at 0x0001e000 failed immediately: errno -524 jffs2: Erase at 0x0001d000 failed immediately: errno -524 jffs2: Erase at 0x0001c000 failed immediately: errno -524 jffs2: Erase at 0x0001b000 failed immediately: errno -524 jffs2: Erase at 0x0001a000 failed immediately: errno -524 jffs2: Erase at 0x00019000 failed immediately: errno -524 jffs2: Erase at 0x00018000 failed immediately: errno -524 jffs2: Erase at 0x00017000 failed immediately: errno -524 jffs2: Erase at 0x00016000 failed immediately: errno -524 jffs2: Erase at 0x00015000 failed immediately: errno -524 jffs2: Erase at 0x00014000 failed immediately: errno -524 jffs2: Erase at 0x00013000 failed immediately: errno -524 jffs2: Erase at 0x00012000 failed immediately: errno -524 jffs2: Erase at 0x00011000 failed immediately: errno -524 jffs2: Erase at 0x00010000 failed immediately: errno -524 jffs2: Erase at 0x0000f000 failed immediately: errno -524 jffs2: Erase at 0x0000e000 failed immediately: errno -524 jffs2: Erase at 0x0000d000 failed immediately: errno -524 jffs2: Erase at 0x0000c000 failed immediately: errno -524 jffs2: Erase at 0x0000b000 failed immediately: errno -524 jffs2: Erase at 0x0000a000 failed immediately: errno -524 jffs2: Erase at 0x00009000 failed immediately: errno -524 jffs2: Erase at 0x00008000 failed immediately: errno -524 jffs2: Erase at 0x00007000 failed immediately: errno -524 jffs2: Erase at 0x00006000 failed immediately: errno -524 jffs2: Erase at 0x00005000 failed immediately: errno -524