================================================================== BUG: KASAN: slab-use-after-free in JFS_SBI fs/jfs/jfs_incore.h:217 [inline] BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x12e/0xa10 fs/jfs/jfs_txnmgr.c:2715 Read of size 8 at addr ffff88802571e798 by task jfsCommit/122 CPU: 1 UID: 0 PID: 122 Comm: jfsCommit Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 JFS_SBI fs/jfs/jfs_incore.h:217 [inline] jfs_lazycommit+0x12e/0xa10 fs/jfs/jfs_txnmgr.c:2715 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 23902: 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+0x3a6/0x690 mm/slub.c:5339 kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1200 [inline] btrfs_opendir+0x183/0x200 fs/btrfs/inode.c:6228 do_dentry_open+0x83d/0x13e0 fs/open.c:949 vfs_open+0x3b/0x350 fs/open.c:1081 do_open fs/namei.c:4671 [inline] path_openat+0x2e43/0x38a0 fs/namei.c:4830 do_file_open+0x23e/0x4a0 fs/namei.c:4859 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 23902: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 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:2687 [inline] slab_free mm/slub.c:6124 [inline] kfree+0x1c1/0x6c0 mm/slub.c:6442 btrfs_release_file+0x6c/0x130 fs/btrfs/file.c:1486 __fput+0x461/0xa90 fs/file_table.c:469 fput_close_sync+0x11f/0x240 fs/file_table.c:574 __do_sys_close fs/open.c:1509 [inline] __se_sys_close fs/open.c:1494 [inline] __x64_sys_close+0x7e/0x110 fs/open.c:1494 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88802571e000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1944 bytes inside of freed 4096-byte region [ffff88802571e000, ffff88802571f000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25718 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813fe1c140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813fe1c140 dead000000000100 dead000000000122 head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 0080000000000003 ffffea000095c601 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 7815420555, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3255 [inline] allocate_slab+0x77/0x660 mm/slub.c:3444 new_slab mm/slub.c:3502 [inline] refill_objects+0x334/0x3c0 mm/slub.c:7134 refill_sheaf mm/slub.c:2804 [inline] __pcs_replace_empty_main+0x328/0x5f0 mm/slub.c:4578 alloc_from_pcs mm/slub.c:4681 [inline] slab_alloc_node mm/slub.c:4815 [inline] __kmalloc_cache_noprof+0x44e/0x690 mm/slub.c:5334 kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1200 [inline] kobject_uevent_env+0x28f/0x9e0 lib/kobject_uevent.c:540 device_add+0x557/0xb80 drivers/base/core.c:3670 device_create_groups_vargs drivers/base/core.c:4371 [inline] device_create+0x269/0x300 drivers/base/core.c:4410 bdi_register_va+0x9c/0x800 mm/backing-dev.c:1098 bdi_register+0xe2/0x140 mm/backing-dev.c:1130 __add_disk+0x747/0xd50 block/genhd.c:533 add_disk_fwnode+0x148/0x480 block/genhd.c:601 add_disk include/linux/blkdev.h:785 [inline] brd_alloc+0x5c9/0x7d0 drivers/block/brd.c:340 brd_init+0xc1/0x120 drivers/block/brd.c:420 page_owner free stack trace missing Memory state around the buggy address: ffff88802571e680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802571e700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802571e780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802571e800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802571e880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================