================================================================== BUG: KASA[ 203.995475][ C1] BUG: KASAN: slab-use-after-free in lbmIODone+0x130e/0x16b0 fs/jfs/jfs_logmgr.c:2192 Read of size 4 at addr ffff888044f89008 by task ksoftirqd/1/30 CPU: 1 UID: 0 PID: 30 Comm: ksoftirqd/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: 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 lbmIODone+0x130e/0x16b0 fs/jfs/jfs_logmgr.c:2192 blk_update_request+0x57b/0xe50 block/blk-mq.c:1016 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1147 blk_complete_reqs block/blk-mq.c:1222 [inline] blk_done_softirq+0x10a/0x160 block/blk-mq.c:1227 handle_softirqs+0x1d9/0x6c0 kernel/softirq.c:622 run_ksoftirqd+0x52/0x180 kernel/softirq.c:1076 smpboot_thread_fn+0x57c/0xa80 kernel/smpboot.c:160 kthread+0x388/0x470 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 Allocated by task 6591: 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+0x3d2/0x6b0 mm/slub.c:5489 _kmalloc_noprof include/linux/slab.h:988 [inline] lbmLogInit fs/jfs/jfs_logmgr.c:1819 [inline] lmLogInit+0x3e5/0x1a20 fs/jfs/jfs_logmgr.c:1267 open_inline_log fs/jfs/jfs_logmgr.c:1173 [inline] lmLogOpen+0x4e3/0xf90 fs/jfs/jfs_logmgr.c:1067 jfs_mount_rw+0xf3/0x670 fs/jfs/jfs_mount.c:257 jfs_fill_super+0x769/0xda0 fs/jfs/super.c:533 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1640 vfs_get_tree+0x92/0x2a0 fs/super.c:1700 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3765 [inline] do_new_mount+0x319/0xdc0 fs/namespace.c:3841 do_mount fs/namespace.c:4174 [inline] __do_sys_mount fs/namespace.c:4390 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4367 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6591: 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:2677 [inline] slab_free mm/slub.c:6377 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6692 lbmLogShutdown fs/jfs/jfs_logmgr.c:1862 [inline] lmLogShutdown+0x456/0x850 fs/jfs/jfs_logmgr.c:1681 lmLogClose+0x28c/0x530 fs/jfs/jfs_logmgr.c:1457 jfs_umount+0x2da/0x3b0 fs/jfs/jfs_umount.c:124 jfs_fill_super+0x9e7/0xda0 fs/jfs/super.c:568 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1640 vfs_get_tree+0x92/0x2a0 fs/super.c:1700 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3765 [inline] do_new_mount+0x319/0xdc0 fs/namespace.c:3841 do_mount fs/namespace.c:4174 [inline] __do_sys_mount fs/namespace.c:4390 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4367 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888044f89000 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 8 bytes inside of freed 256-byte region [ffff888044f89000, ffff888044f89100) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x44f88 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813ffb1b40 dead000000000122 0000000000000000 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813ffb1b40 dead000000000122 0000000000000000 head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 0080000000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff head: 0000000000000000 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6591, tgid 6590 (syz.0.26), ts 203927190283, free_ts 203853648754 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x262a/0x26a0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3266 [inline] allocate_slab+0x79/0x5e0 mm/slub.c:3380 new_slab mm/slub.c:3426 [inline] refill_objects+0x2d8/0x350 mm/slub.c:7310 refill_sheaf mm/slub.c:2804 [inline] __pcs_replace_empty_main+0x330/0x690 mm/slub.c:4675 alloc_from_pcs mm/slub.c:4773 [inline] slab_alloc_node mm/slub.c:4905 [inline] __kmalloc_cache_noprof+0x468/0x6b0 mm/slub.c:5485 _kmalloc_noprof include/linux/slab.h:988 [inline] lbmLogInit fs/jfs/jfs_logmgr.c:1819 [inline] lmLogInit+0x3e5/0x1a20 fs/jfs/jfs_logmgr.c:1267 open_inline_log fs/jfs/jfs_logmgr.c:1173 [inline] lmLogOpen+0x4e3/0xf90 fs/jfs/jfs_logmgr.c:1067 jfs_mount_rw+0xf3/0x670 fs/jfs/jfs_mount.c:257 jfs_fill_super+0x769/0xda0 fs/jfs/super.c:533 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1640 vfs_get_tree+0x92/0x2a0 fs/super.c:1700 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3765 [inline] do_new_mount+0x319/0xdc0 fs/namespace.c:3841 do_mount fs/namespace.c:4174 [inline] __do_sys_mount fs/namespace.c:4390 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4367 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 page last free pid 6592 tgid 6592 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x10e7/0x11c0 mm/page_alloc.c:2950 mm_free_pgd kernel/fork.c:590 [inline] __mmdrop+0xf3/0x480 kernel/fork.c:733 exit_mm+0x186/0x240 kernel/exit.c:615 do_exit+0x6cd/0x2360 kernel/exit.c:997 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152 __do_sys_exit_group kernel/exit.c:1163 [inline] __se_sys_exit_group kernel/exit.c:1161 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1161 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888044f88f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888044f88f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888044f89000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888044f89080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888044f89100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================