================================================================== BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x749/0xaa0 fs/jfs/jfs_txnmgr.c:2737 Read of size 4 at addr ffff88807dfa7494 by task jfsCommit/118 CPU: 1 UID: 0 PID: 118 Comm: jfsCommit Not tainted syzkaller #0 PREEMPT(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_lazycommit+0x749/0xaa0 fs/jfs/jfs_txnmgr.c:2737 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 6145: 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+0x31c/0x660 mm/slub.c:5339 kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1204 [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:3764 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3840 do_mount fs/namespace.c:4173 [inline] __do_sys_mount fs/namespace.c:4362 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4339 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 5948: 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+0x1c1/0x630 mm/slub.c:6442 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+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807dfa7400 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of freed 256-byte region [ffff88807dfa7400, ffff88807dfa7500) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807dfa6400 pfn:0x7dfa6 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 ffff88801b041b40 ffff88801b040708 ffffea000083fd90 raw: ffff88807dfa6400 000000000010000a 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b041b40 ffff88801b040708 ffffea000083fd90 head: ffff88807dfa6400 000000000010000a 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffea0001f7e981 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5883, tgid 5883 (syz-executor), ts 87607284622, free_ts 86979329750 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+0x24dc/0x2580 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+0x331/0x3c0 mm/slub.c:7134 refill_sheaf mm/slub.c:2804 [inline] __pcs_replace_empty_main+0x2b9/0x620 mm/slub.c:4578 alloc_from_pcs mm/slub.c:4681 [inline] slab_alloc_node mm/slub.c:4815 [inline] __do_kmalloc_node mm/slub.c:5218 [inline] __kmalloc_node_track_caller_noprof+0x572/0x7b0 mm/slub.c:5327 kmemdup_noprof mm/util.c:138 [inline] kmemdup_noprof include/linux/fortify-string.h:763 [inline] kmemdup_array+0x3f/0x80 mm/util.c:158 ipt_register_table+0x295/0x7f0 net/ipv4/netfilter/ip_tables.c:1770 iptable_security_table_init+0x41/0x70 net/ipv4/netfilter/iptable_security.c:46 xt_find_table_lock+0x30c/0x3e0 net/netfilter/x_tables.c:1260 xt_request_find_table_lock+0x26/0x100 net/netfilter/x_tables.c:1285 get_info net/ipv4/netfilter/ip_tables.c:963 [inline] do_ipt_get_ctl+0x716/0x1240 net/ipv4/netfilter/ip_tables.c:1659 nf_getsockopt+0x26e/0x290 net/netfilter/nf_sockopt.c:116 ip_getsockopt+0x19e/0x230 net/ipv4/ip_sockglue.c:1777 do_sock_getsockopt+0x2d3/0x3f0 net/socket.c:2398 page last free pid 5855 tgid 5855 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 __slab_free+0x263/0x2b0 mm/slub.c:5532 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 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:4501 [inline] slab_alloc_node mm/slub.c:4830 [inline] __do_kmalloc_node mm/slub.c:5218 [inline] __kmalloc_noprof+0x316/0x760 mm/slub.c:5231 kmalloc_noprof include/linux/slab.h:966 [inline] kzalloc_noprof include/linux/slab.h:1204 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x28b/0x550 security/tomoyo/realpath.c:80 tomoyo_path_perm+0x318/0x560 security/tomoyo/file.c:836 tomoyo_path_symlink+0xab/0xf0 security/tomoyo/tomoyo.c:212 security_path_symlink+0x16f/0x360 security/security.c:1476 filename_symlinkat+0x134/0x410 fs/namei.c:5638 __do_sys_symlink fs/namei.c:5667 [inline] __se_sys_symlink+0x4d/0x2b0 fs/namei.c:5663 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 Memory state around the buggy address: ffff88807dfa7380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807dfa7400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807dfa7480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807dfa7500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807dfa7580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================