================================================================== BUG: KASAN: use-after-free in instrument_atomic_write include/linux/instrumented.h:86 [inline] BUG: KASAN: use-after-free in clear_bit include/asm-generic/bitops/instrumented-atomic.h:41 [inline] BUG: KASAN: use-after-free in txEnd+0x2c4/0x510 fs/jfs/jfs_txnmgr.c:554 Write of size 8 at addr ffff0000dd83c040 by task jfsCommit/248 CPU: 1 PID: 248 Comm: jfsCommit Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 Call trace: dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106 print_address_description+0x78/0x30c mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xec/0x15c mm/kasan/report.c:451 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x270/0x2b0 mm/kasan/generic.c:189 __kasan_check_write+0x44/0x54 mm/kasan/shadow.c:37 instrument_atomic_write include/linux/instrumented.h:86 [inline] clear_bit include/asm-generic/bitops/instrumented-atomic.h:41 [inline] txEnd+0x2c4/0x510 fs/jfs/jfs_txnmgr.c:554 txLazyCommit fs/jfs/jfs_txnmgr.c:2718 [inline] jfs_lazycommit+0x4a4/0x9bc fs/jfs/jfs_txnmgr.c:2766 kthread+0x374/0x454 kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:856 Allocated by task 5746: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb0/0xf0 mm/kasan/common.c:522 kasan_kmalloc include/linux/kasan.h:264 [inline] kmem_cache_alloc_trace+0x274/0x3fc mm/slub.c:3252 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] open_inline_log fs/jfs/jfs_logmgr.c:1167 [inline] lmLogOpen+0x288/0xd68 fs/jfs/jfs_logmgr.c:1077 jfs_mount_rw+0xe4/0x50c fs/jfs/jfs_mount.c:253 jfs_fill_super+0x49c/0x960 fs/jfs/super.c:570 mount_bdev+0x264/0x358 fs/super.c:1400 jfs_do_mount+0x44/0x58 fs/jfs/super.c:675 legacy_get_tree+0xd4/0x16c fs/fs_context.c:611 vfs_get_tree+0x90/0x274 fs/super.c:1530 do_new_mount+0x228/0x810 fs/namespace.c:3034 path_mount+0x5b4/0x1000 fs/namespace.c:3364 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount fs/namespace.c:3562 [inline] __arm64_sys_mount+0x514/0x5e4 fs/namespace.c:3562 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 Freed by task 4925: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4c/0x84 mm/kasan/common.c:46 kasan_set_free_info+0x28/0x4c mm/kasan/generic.c:360 ____kasan_slab_free+0x118/0x164 mm/kasan/common.c:366 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0x128/0x1e8 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0x170/0x40c mm/slub.c:4564 lmLogClose+0x250/0x4c8 fs/jfs/jfs_logmgr.c:-1 jfs_umount+0x244/0x328 fs/jfs/jfs_umount.c:116 jfs_put_super+0x90/0x188 fs/jfs/super.c:194 generic_shutdown_super+0x130/0x2f0 fs/super.c:475 kill_block_super+0x70/0xdc fs/super.c:1427 deactivate_locked_super+0xb8/0x13c fs/super.c:335 deactivate_super+0xf8/0x118 fs/super.c:366 cleanup_mnt+0x3a4/0x458 fs/namespace.c:1148 __cleanup_mnt+0x20/0x30 fs/namespace.c:1155 task_work_run+0x12c/0x1e0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] do_notify_resume+0x24b4/0x3128 arch/arm64/kernel/signal.c:949 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline] el0_svc+0xf0/0x1e0 arch/arm64/kernel/entry-common.c:609 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 The buggy address belongs to the object at ffff0000dd83c000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 64 bytes inside of 1024-byte region [ffff0000dd83c000, ffff0000dd83c400) The buggy address belongs to the page: page:0000000064b30b8f refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11d838 head:0000000064b30b8f order:3 compound_mapcount:0 compound_pincount:0 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 0000000000000000 0000000a00000001 ffff0000c0002780 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000dd83bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000dd83bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff0000dd83c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000dd83c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000dd83c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ... 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Unable to handle kernel paging request at virtual address dfff800000000006 Mem abort info: ESR = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 [dfff800000000006] address between user and kernel address ranges Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 248 Comm: jfsCommit Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) pc : write_special_inodes fs/jfs/jfs_logmgr.c:208 [inline] pc : lmLogSync+0x124/0x88c fs/jfs/jfs_logmgr.c:943 lr : write_special_inodes fs/jfs/jfs_logmgr.c:207 [inline] lr : lmLogSync+0x100/0x88c fs/jfs/jfs_logmgr.c:943 sp : ffff80001efa7b40 x29: ffff80001efa7c10 x28: 1ffff00003d1b244 x27: dfff800000000000 x26: 1ffff000028de248 x25: dfff800000000000 x24: ffff80001efa7b60 x23: 0000000000000003 x22: ffff700003df4f6c x21: 0000000000000030 x20: ffff0000ecbf0838 x19: ffff0000d59fd000 x18: 1fffe00034214596 x17: 1fffe00034214596 x16: ffff8000082d6484 x15: ffff80001422ef00 x14: ffff0001a10a2cc0 x13: ffff0001a10a2cbc x12: 0000000000ff0100 x11: 0000000000000000 x10: 0000000000000000 x9 : e1db328dde2b4400 x8 : 0000000000000006 x7 : 0000000000000000 x6 : ffff80001129a838 x5 : 0000000000000000 x4 : 000000000000000c x3 : 0000000000000030 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: write_special_inodes fs/jfs/jfs_logmgr.c:208 [inline] lmLogSync+0x124/0x88c fs/jfs/jfs_logmgr.c:943 jfs_syncpt+0x70/0x94 fs/jfs/jfs_logmgr.c:1049 txEnd+0x294/0x510 fs/jfs/jfs_txnmgr.c:549 txLazyCommit fs/jfs/jfs_txnmgr.c:2718 [inline] jfs_lazycommit+0x4a4/0x9bc fs/jfs/jfs_txnmgr.c:2766 kthread+0x374/0x454 kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:856 Code: 97c1e949 f94002a8 9100c115 d343fea8 (387b6908) ---[ end trace 71c36beaeb634c08 ]--- ---------------- Code disassembly (best guess): 0: 97c1e949 bl 0xffffffffff07a524 4: f94002a8 ldr x8, [x21] 8: 9100c115 add x21, x8, #0x30 c: d343fea8 lsr x8, x21, #3 * 10: 387b6908 ldrb w8, [x8, x27] <-- trapping instruction