... Log Wrap ... Log Wrap ... Log Wrap ...
==================================================================
BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x771/0xac0 fs/jfs/jfs_txnmgr.c:2738
Read of size 4 at addr ffff888031ab7694 by task jfsCommit/121

CPU: 1 UID: 0 PID: 121 Comm: jfsCommit Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 jfs_lazycommit+0x771/0xac0 fs/jfs/jfs_txnmgr.c:2738
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 18245:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x321/0x600 mm/slub.c:5563
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 jfs_fill_super+0xc2/0xda0 fs/jfs/super.c:452
 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1887
 vfs_get_tree+0x92/0x2a0 fs/super.c:1947
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3772 [inline]
 do_new_mount+0x319/0xdc0 fs/namespace.c:3848
 do_mount fs/namespace.c:4181 [inline]
 __do_sys_mount fs/namespace.c:4397 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5614:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6499 [inline]
 kfree+0x1c5/0x650 mm/slub.c:6792
 generic_shutdown_super+0x13d/0x2d0 fs/super.c:769
 kill_block_super+0x44/0xa0 fs/super.c:1918
 deactivate_locked_super+0xbc/0x110 fs/super.c:603
 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
 do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888031ab7600
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 148 bytes inside of
 freed 256-byte region [ffff888031ab7600, ffff888031ab7700)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888031ab7200 pfn:0x31ab6
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88801b005b40 ffff88801b004708 ffffea0001ff6110
raw: ffff888031ab7200 000000000010000f 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801b005b40 ffff88801b004708 ffffea0001ff6110
head: ffff888031ab7200 000000000010000f 00000000f5000000 0000000000000000
head: 00fff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x10d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_NOLOCKDEP), pid 5857, tgid 5856 (syz.2.16), ts 84557645373
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab+0x7d/0x620 mm/slub.c:3462
 new_slab mm/slub.c:3513 [inline]
 refill_objects+0x2d5/0x350 mm/slub.c:7410
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __do_kmalloc_node mm/slub.c:5413 [inline]
 __kmalloc_flags_noprof+0x5c6/0x7a0 mm/slub.c:5602
 _kmalloc_flags_noprof mm/slab.h:55 [inline]
 __alloc_empty_sheaf+0x28/0x40 mm/slub.c:2822
 alloc_empty_sheaf mm/slub.c:2842 [inline]
 __pcs_replace_empty_main+0x43b/0x6c0 mm/slub.c:4769
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 kmem_cache_alloc_noprof+0x399/0x600 mm/slub.c:5010
 xfs_btree_alloc_cursor fs/xfs/libxfs/xfs_btree.h:683 [inline]
 xfs_inobt_init_cursor+0x79/0x230 fs/xfs/libxfs/xfs_ialloc_btree.c:485
 xfs_imap_lookup+0x16b/0x520 fs/xfs/libxfs/xfs_ialloc.c:2423
 xfs_imap+0x2de/0x8d0 fs/xfs/libxfs/xfs_ialloc.c:2541
 xfs_iget_cache_miss fs/xfs/xfs_icache.c:648 [inline]
 xfs_iget+0xb33/0x2f30 fs/xfs/xfs_icache.c:807
 xfs_mountfs+0x1165/0x2380 fs/xfs/xfs_mount.c:1070
 xfs_fs_fill_super+0x115a/0x15a0 fs/xfs/xfs_super.c:1987
page last free pid 24 tgid 24 ts 84394308070 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 __free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962
 rcu_do_batch kernel/rcu/tree.c:2650 [inline]
 rcu_core+0x926/0x1260 kernel/rcu/tree.c:2919
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1108
 smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff888031ab7580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888031ab7600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888031ab7680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff888031ab7700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888031ab7780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================