================================================================== BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x6d7/0xa10 fs/jfs/jfs_txnmgr.c:2738 Read of size 4 at addr ffff888039820894 by task jfsCommit/127 CPU: 0 UID: 0 PID: 127 Comm: jfsCommit Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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 jfs_lazycommit+0x6d7/0xa10 fs/jfs/jfs_txnmgr.c:2738 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 11415: 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:5420 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] jfs_fill_super+0xc2/0xd80 fs/jfs/super.c:452 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 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 6879: 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:2689 [inline] slab_free mm/slub.c:6251 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6566 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1725 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 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:67 [inline] exit_to_user_mode_loop+0x193/0x680 kernel/entry/common.c:98 __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:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888039820800 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of freed 256-byte region [ffff888039820800, ffff888039820900) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x39820 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 ffff88801a00ab40 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88801a00ab40 dead000000000100 dead000000000122 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 0x10d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_NOLOCKDEP), pid 5802, tgid 5801 (syz.1.2), ts 95312338523, free_ts 94998766055 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1853 prep_new_page mm/page_alloc.c:1861 [inline] get_page_from_freelist+0x28b2/0x2930 mm/page_alloc.c:3941 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5221 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7272 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4652 alloc_from_pcs mm/slub.c:4750 [inline] slab_alloc_node mm/slub.c:4884 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kmalloc_noprof+0x530/0x7b0 mm/slub.c:5308 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] __alloc_empty_sheaf mm/slub.c:2768 [inline] alloc_empty_sheaf mm/slub.c:2783 [inline] __pcs_replace_empty_main+0x331/0x720 mm/slub.c:4647 alloc_from_pcs mm/slub.c:4750 [inline] slab_alloc_node mm/slub.c:4884 [inline] kmem_cache_alloc_noprof+0x433/0x680 mm/slub.c:4906 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+0x47e/0xe40 fs/xfs/libxfs/xfs_ialloc.c:2515 xfs_iget_cache_miss fs/xfs/xfs_icache.c:649 [inline] xfs_iget+0xb24/0x2d70 fs/xfs/xfs_icache.c:808 xfs_mountfs+0x110c/0x22e0 fs/xfs/xfs_mount.c:1070 xfs_fs_fill_super+0x11b5/0x1600 fs/xfs/xfs_super.c:1938 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 page last free pid 5605 tgid 5605 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1397 [inline] __free_frozen_pages+0xfe5/0x10d0 mm/page_alloc.c:2938 __slab_free+0x252/0x2a0 mm/slub.c:5613 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4570 [inline] slab_alloc_node mm/slub.c:4899 [inline] kmem_cache_alloc_lru_noprof+0x33c/0x680 mm/slub.c:4918 alloc_inode+0x6a/0x1b0 fs/inode.c:345 new_inode+0x22/0x170 fs/inode.c:1179 debugfs_get_inode fs/debugfs/inode.c:72 [inline] __debugfs_create_file+0xb8/0x400 fs/debugfs/inode.c:433 debugfs_create_file_short+0x3f/0x60 fs/debugfs/inode.c:471 add_files net/mac80211/debugfs_netdev.c:942 [inline] ieee80211_debugfs_add_netdev net/mac80211/debugfs_netdev.c:1010 [inline] ieee80211_debugfs_recreate_netdev+0x276/0x1460 net/mac80211/debugfs_netdev.c:1034 ieee80211_if_add+0xc65/0x13d0 net/mac80211/iface.c:2391 ieee80211_register_hw+0x3ebc/0x4a70 net/mac80211/main.c:1641 mac80211_hwsim_new_radio+0x3051/0x54f0 drivers/net/wireless/virtual/mac80211_hwsim.c:6019 hwsim_new_radio_nl+0xf6a/0x1c00 drivers/net/wireless/virtual/mac80211_hwsim.c:6726 genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114 Memory state around the buggy address: ffff888039820780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888039820800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888039820880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888039820900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888039820980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================