================================================================== BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x753/0xa60 fs/jfs/jfs_txnmgr.c:2735 Read of size 4 at addr ffff888078ac0e94 by task jfsCommit/111 CPU: 1 PID: 111 Comm: jfsCommit Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xac/0x220 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 jfs_lazycommit+0x753/0xa60 fs/jfs/jfs_txnmgr.c:2735 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Allocated by task 19859: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] jfs_fill_super+0xd6/0xac0 fs/jfs/super.c:495 mount_bdev+0x22b/0x2d0 fs/super.c:1643 legacy_get_tree+0xea/0x180 fs/fs_context.c:662 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24b/0xa40 fs/namespace.c:3377 do_mount fs/namespace.c:3717 [inline] __do_sys_mount fs/namespace.c:3926 [inline] __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3903 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 8275: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843 generic_shutdown_super+0x134/0x2b0 fs/super.c:693 kill_block_super+0x44/0x90 fs/super.c:1660 deactivate_locked_super+0x97/0x100 fs/super.c:481 cleanup_mnt+0x429/0x4c0 fs/namespace.c:1250 task_work_run+0x1ce/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3452 drop_sysctl_table+0x356/0x4b0 fs/proc/proc_sysctl.c:1515 drop_sysctl_table+0x36d/0x4b0 fs/proc/proc_sysctl.c:1518 unregister_sysctl_table+0x41/0x60 fs/proc/proc_sysctl.c:1536 neigh_sysctl_unregister+0x78/0xa0 net/core/neighbour.c:3891 devinet_sysctl_unregister net/ipv4/devinet.c:2685 [inline] inetdev_destroy net/ipv4/devinet.c:330 [inline] inetdev_event+0x7b8/0x15c0 net/ipv4/devinet.c:1636 notifier_call_chain+0x197/0x390 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline] call_netdevice_notifiers net/core/dev.c:2078 [inline] unregister_netdevice_many_notify+0xf36/0x1810 net/core/dev.c:11086 sit_exit_batch_net+0x49c/0x4e0 net/ipv6/sit.c:1888 ops_exit_list net/core/net_namespace.c:178 [inline] cleanup_net+0x77f/0xb90 net/core/net_namespace.c:652 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Second to last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2721 [inline] call_rcu+0x158/0x930 kernel/rcu/tree.c:2837 fib_create_info+0x1845/0x2460 net/ipv4/fib_semantics.c:1590 fib_table_insert+0xc7/0x1b50 net/ipv4/fib_trie.c:1217 fib_magic+0x2c5/0x390 net/ipv4/fib_frontend.c:1118 fib_add_ifaddr+0x144/0x5e0 net/ipv4/fib_frontend.c:1140 fib_netdev_event+0x389/0x490 net/ipv4/fib_frontend.c:1500 notifier_call_chain+0x197/0x390 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline] call_netdevice_notifiers net/core/dev.c:2078 [inline] __dev_notify_flags+0x18e/0x2e0 net/core/dev.c:-1 dev_change_flags+0xe8/0x1a0 net/core/dev.c:8762 do_setlink+0xc74/0x3fb0 net/core/rtnetlink.c:2905 __rtnl_newlink net/core/rtnetlink.c:3703 [inline] rtnl_newlink+0x175b/0x2020 net/core/rtnetlink.c:3750 rtnetlink_rcv_msg+0x7c7/0xf10 net/core/rtnetlink.c:6475 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x46a/0x620 net/socket.c:2201 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xde/0xf0 net/socket.c:2209 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888078ac0e00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of freed 256-byte region [ffff888078ac0e00, ffff888078ac0f00) The buggy address belongs to the physical page: page:ffffea0001e2b000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x78ac0 head:ffffea0001e2b000 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0 ksm flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017841b40 ffffea0000a84280 dead000000000003 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5791, tgid 5791 (syz-executor), ts 84708524414, free_ts 84611379744 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 alloc_slab_page+0x5d/0x170 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2e0 mm/slub.c:2081 ___slab_alloc+0xc6d/0x1300 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0xa4/0x240 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:721 [inline] new_dir fs/proc/proc_sysctl.c:969 [inline] get_subdir fs/proc/proc_sysctl.c:1013 [inline] sysctl_mkdir_p fs/proc/proc_sysctl.c:1308 [inline] __register_sysctl_table+0xac9/0x1240 fs/proc/proc_sysctl.c:1389 neigh_sysctl_register+0x9cc/0xab0 net/core/neighbour.c:3870 devinet_sysctl_register+0xa8/0x1f0 net/ipv4/devinet.c:2670 inetdev_init+0x2b4/0x4f0 net/ipv4/devinet.c:287 inetdev_event+0x308/0x15c0 net/ipv4/devinet.c:1568 notifier_call_chain+0x197/0x390 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline] call_netdevice_notifiers net/core/dev.c:2078 [inline] register_netdevice+0x160c/0x1ae0 net/core/dev.c:10313 cfg80211_register_netdevice+0x159/0x2f0 net/wireless/core.c:1457 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1154 [inline] free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429 __slab_free+0x35e/0x410 mm/slub.c:3736 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] __kmem_cache_alloc_node+0x13e/0x260 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0xa4/0x240 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:721 [inline] fib_create_info+0xa61/0x2460 net/ipv4/fib_semantics.c:1459 fib_table_insert+0xc7/0x1b50 net/ipv4/fib_trie.c:1217 fib_magic+0x2c5/0x390 net/ipv4/fib_frontend.c:1118 fib_add_ifaddr+0x38d/0x5e0 net/ipv4/fib_frontend.c:1155 fib_netdev_event+0x389/0x490 net/ipv4/fib_frontend.c:1500 notifier_call_chain+0x197/0x390 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline] call_netdevice_notifiers net/core/dev.c:2078 [inline] __dev_notify_flags+0x18e/0x2e0 net/core/dev.c:-1 Memory state around the buggy address: ffff888078ac0d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888078ac0e00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888078ac0e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888078ac0f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888078ac0f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================