================================================================== BUG: KASAN: use-after-free in write_special_inodes fs/jfs/jfs_logmgr.c:207 [inline] BUG: KASAN: use-after-free in lmLogSync+0x1f4/0x894 fs/jfs/jfs_logmgr.c:937 Read of size 8 at addr ffff0000f57b2020 by task syz-executor/4320 CPU: 1 PID: 4320 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106 print_address_description+0x88/0x218 mm/kasan/report.c:316 print_report+0x50/0x68 mm/kasan/report.c:420 kasan_report+0xa8/0x100 mm/kasan/report.c:524 __asan_report_load8_noabort+0x2c/0x38 mm/kasan/report_generic.c:351 write_special_inodes fs/jfs/jfs_logmgr.c:207 [inline] lmLogSync+0x1f4/0x894 fs/jfs/jfs_logmgr.c:937 jfs_syncpt+0x70/0x94 fs/jfs/jfs_logmgr.c:1041 jfs_sync_fs+0x8c/0xac fs/jfs/super.c:685 sync_filesystem+0xe8/0x218 fs/sync.c:56 generic_shutdown_super+0x70/0x324 fs/super.c:474 kill_block_super+0x70/0xdc fs/super.c:1470 deactivate_locked_super+0xac/0x124 fs/super.c:332 deactivate_super+0xe8/0x108 fs/super.c:363 cleanup_mnt+0x37c/0x404 fs/namespace.c:1191 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198 task_work_run+0x1ec/0x270 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x2038/0x2b28 arch/arm64/kernel/signal.c:1137 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x138 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Allocated by task 5501: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:52 kasan_save_alloc_info+0x28/0x34 mm/kasan/generic.c:505 __kasan_slab_alloc+0x70/0x88 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x74/0x43c mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc_lru+0x1b0/0x298 mm/slub.c:3390 alloc_inode_sb include/linux/fs.h:3245 [inline] jfs_alloc_inode+0x2c/0x68 fs/jfs/super.c:105 alloc_inode fs/inode.c:261 [inline] new_inode_pseudo+0x68/0x1cc fs/inode.c:1063 new_inode+0x38/0x174 fs/inode.c:1091 diReadSpecial+0x58/0x5e0 fs/jfs/jfs_imap.c:426 jfs_mount+0x158/0x750 fs/jfs/jfs_mount.c:108 jfs_fill_super+0x3fc/0x948 fs/jfs/super.c:556 mount_bdev+0x264/0x358 fs/super.c:1443 jfs_do_mount+0x44/0x58 fs/jfs/super.c:670 legacy_get_tree+0xd4/0x16c fs/fs_context.c:632 vfs_get_tree+0x90/0x274 fs/super.c:1573 do_new_mount+0x228/0x810 fs/namespace.c:3078 path_mount+0x5b4/0xe78 fs/namespace.c:3408 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount fs/namespace.c:3606 [inline] __arm64_sys_mount+0x49c/0x584 fs/namespace.c:3606 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Freed by task 21: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:52 kasan_save_free_info+0x3c/0x60 mm/kasan/generic.c:516 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:236 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x16c/0x1ec mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free+0x11c/0x324 mm/slub.c:3709 jfs_free_inode+0x28/0x38 fs/jfs/super.c:116 i_callback+0x50/0x78 fs/inode.c:250 rcu_do_batch kernel/rcu/tree.c:2297 [inline] rcu_core+0x81c/0x18ac kernel/rcu/tree.c:2557 rcu_core_si+0x10/0x1c kernel/rcu/tree.c:2574 handle_softirqs+0x318/0xc6c kernel/softirq.c:596 run_ksoftirqd+0x7c/0x2a0 kernel/softirq.c:963 smpboot_thread_fn+0x4b0/0x964 kernel/smpboot.c:164 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 Last potentially related work creation: kasan_save_stack+0x40/0x70 mm/kasan/common.c:45 __kasan_record_aux_stack+0xc0/0xdc mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:496 call_rcu+0x100/0x954 kernel/rcu/tree.c:2849 destroy_inode fs/inode.c:316 [inline] evict+0x748/0x810 fs/inode.c:720 iput_final fs/inode.c:1834 [inline] iput+0x764/0x7f4 fs/inode.c:1860 diFreeSpecial+0x78/0x100 fs/jfs/jfs_imap.c:552 jfs_umount+0x1cc/0x328 fs/jfs/jfs_umount.c:91 jfs_put_super+0x90/0x188 fs/jfs/super.c:194 generic_shutdown_super+0x130/0x324 fs/super.c:501 kill_block_super+0x70/0xdc fs/super.c:1470 deactivate_locked_super+0xac/0x124 fs/super.c:332 deactivate_super+0xe8/0x108 fs/super.c:363 cleanup_mnt+0x37c/0x404 fs/namespace.c:1191 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198 task_work_run+0x1ec/0x270 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x2038/0x2b28 arch/arm64/kernel/signal.c:1137 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x138 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Second to last potentially related work creation: kasan_save_stack+0x40/0x70 mm/kasan/common.c:45 __kasan_record_aux_stack+0xc0/0xdc mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:496 call_rcu+0x100/0x954 kernel/rcu/tree.c:2849 destroy_inode fs/inode.c:316 [inline] evict+0x748/0x810 fs/inode.c:720 iput_final fs/inode.c:1834 [inline] iput+0x764/0x7f4 fs/inode.c:1860 diFreeSpecial+0x78/0x100 fs/jfs/jfs_imap.c:552 jfs_umount+0x1cc/0x328 fs/jfs/jfs_umount.c:91 jfs_put_super+0x90/0x188 fs/jfs/super.c:194 generic_shutdown_super+0x130/0x324 fs/super.c:501 kill_block_super+0x70/0xdc fs/super.c:1470 deactivate_locked_super+0xac/0x124 fs/super.c:332 deactivate_super+0xe8/0x108 fs/super.c:363 cleanup_mnt+0x37c/0x404 fs/namespace.c:1191 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198 task_work_run+0x1ec/0x270 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x2038/0x2b28 arch/arm64/kernel/signal.c:1137 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x138 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 The buggy address belongs to the object at ffff0000f57b1bc0 which belongs to the cache jfs_ip of size 2240 The buggy address is located 1120 bytes inside of 2240-byte region [ffff0000f57b1bc0, ffff0000f57b2480) The buggy address belongs to the physical page: page:000000008a769876 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1357b0 head:000000008a769876 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff0000f5fb9101 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 0000000000000000 dead000000000122 ffff0000c4f70900 raw: 0000000000000000 00000000000d000d 00000001ffffffff ffff0000f5fb9101 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f57b1f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000f57b1f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000f57b2000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000f57b2080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000f57b2100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Unable to handle kernel paging request at virtual address dfff800000000006 KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] 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: 4320 Comm: syz-executor 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+0x220/0x894 fs/jfs/jfs_logmgr.c:937 lr : write_special_inodes fs/jfs/jfs_logmgr.c:207 [inline] lr : lmLogSync+0x1fc/0x894 fs/jfs/jfs_logmgr.c:937 sp : ffff800020ce77c0 x29: ffff800020ce7890 x28: 1ffff00002a17aa8 x27: dfff800000000000 x26: 0000000000000002 x25: 0000000000000002 x24: ffff800020ce77e0 x23: dfff800000000000 x22: ffff70000419cefc x21: 0000000000000030 x20: ffff0000d1e76438 x19: ffff0000f648a000 x18: ffff800011abbcc0 x17: 0000000000000000 x16: ffff800008042d90 x15: 0000000000000000 x14: 00000000ffffffff x13: 0000000000000001 x12: 0000000000ff0100 x11: ff008000086d0d3c x10: 0000000000000000 x9 : 3e8c2d5d797dd800 x8 : 0000000000000006 x7 : 0000000000000000 x6 : 0000000000000001 x5 : ffff800020ce7198 x4 : 0000000000000000 x3 : ffff8000086d0dfc x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: write_special_inodes fs/jfs/jfs_logmgr.c:208 [inline] lmLogSync+0x220/0x894 fs/jfs/jfs_logmgr.c:937 jfs_syncpt+0x70/0x94 fs/jfs/jfs_logmgr.c:1041 jfs_sync_fs+0x8c/0xac fs/jfs/super.c:685 sync_filesystem+0xe8/0x218 fs/sync.c:56 generic_shutdown_super+0x70/0x324 fs/super.c:474 kill_block_super+0x70/0xdc fs/super.c:1470 deactivate_locked_super+0xac/0x124 fs/super.c:332 deactivate_super+0xe8/0x108 fs/super.c:363 cleanup_mnt+0x37c/0x404 fs/namespace.c:1191 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198 task_work_run+0x1ec/0x270 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x2038/0x2b28 arch/arm64/kernel/signal.c:1137 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x138 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Code: 97c0f73b f94002a8 9100c115 d343fea8 (387b6908) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: 97c0f73b bl 0xffffffffff03dcec 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