================================================================== BUG: KASAN: use-after-free in jfs_lazycommit+0x74d/0xa70 fs/jfs/jfs_txnmgr.c:2736 Read of size 4 at addr ffff88802e9de894 by task jfsCommit/107 CPU: 0 PID: 107 Comm: jfsCommit Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 jfs_lazycommit+0x74d/0xa70 fs/jfs/jfs_txnmgr.c:2736 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 12420: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] jfs_fill_super+0xd8/0xad0 fs/jfs/super.c:495 mount_bdev+0x287/0x3c0 fs/super.c:1443 legacy_get_tree+0xe6/0x180 fs/fs_context.c:632 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x24a/0xa40 fs/namespace.c:3078 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 6420: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3700 generic_shutdown_super+0x130/0x340 fs/super.c:501 kill_block_super+0x7c/0xe0 fs/super.c:1470 deactivate_locked_super+0x93/0xf0 fs/super.c:332 cleanup_mnt+0x42c/0x4b0 fs/namespace.c:1191 task_work_run+0x1d0/0x260 kernel/task_work.c:203 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+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 kvfree_call_rcu+0x103/0x870 kernel/rcu/tree.c:3405 drop_sysctl_table+0x359/0x4e0 fs/proc/proc_sysctl.c:1731 drop_sysctl_table+0x348/0x4e0 fs/proc/proc_sysctl.c:1734 unregister_sysctl_table+0x85/0x130 fs/proc/proc_sysctl.c:1769 neigh_sysctl_unregister+0x74/0x90 net/core/neighbour.c:3877 devinet_sysctl_unregister net/ipv4/devinet.c:2664 [inline] inetdev_destroy net/ipv4/devinet.c:329 [inline] inetdev_event+0x731/0x1400 net/ipv4/devinet.c:1615 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] unregister_netdevice_many+0x1086/0x1930 net/core/dev.c:10990 unregister_netdevice_queue+0x324/0x370 net/core/dev.c:10921 bpq_device_event+0x352/0x8b0 drivers/net/hamradio/bpqether.c:552 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] unregister_netdevice_many+0x1086/0x1930 net/core/dev.c:10990 unregister_netdevice_queue+0x324/0x370 net/core/dev.c:10921 unregister_netdevice include/linux/netdevice.h:3075 [inline] nsim_destroy+0x49/0x150 drivers/net/netdevsim/netdev.c:382 __nsim_dev_port_del+0x155/0x1c0 drivers/net/netdevsim/dev.c:1433 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1445 [inline] nsim_dev_reload_destroy+0x283/0x480 drivers/net/netdevsim/dev.c:1662 nsim_drv_remove+0x5c/0x160 drivers/net/netdevsim/dev.c:1678 device_remove drivers/base/dd.c:548 [inline] __device_release_driver drivers/base/dd.c:1260 [inline] device_release_driver_internal+0x4be/0x850 drivers/base/dd.c:1286 bus_remove_device+0x2e2/0x400 drivers/base/bus.c:531 device_del+0x6af/0xaf0 drivers/base/core.c:3885 device_unregister+0x1c/0xc0 drivers/base/core.c:3928 nsim_bus_dev_del drivers/net/netdevsim/bus.c:310 [inline] del_device_store+0x2ad/0x360 drivers/net/netdevsim/bus.c:219 kernfs_fop_write_iter+0x3b2/0x520 fs/kernfs/file.c:352 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x4b1/0xa30 fs/read_write.c:584 ksys_write+0x14c/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 call_rcu+0x14f/0x990 kernel/rcu/tree.c:2849 free_fib_info net/ipv4/fib_semantics.c:257 [inline] fib_info_put include/net/ip_fib.h:583 [inline] fib_release_info+0x684/0x740 net/ipv4/fib_semantics.c:283 fib_table_delete+0xdd7/0xff0 net/ipv4/fib_trie.c:1757 fib_magic+0x301/0x3c0 net/ipv4/fib_frontend.c:1120 fib_del_ifaddr+0x107e/0x1480 net/ipv4/fib_frontend.c:1331 fib_inetaddr_event+0xb7/0x1c0 net/ipv4/fib_frontend.c:1462 notifier_call_chain kernel/notifier.c:87 [inline] blocking_notifier_call_chain+0x103/0x1b0 kernel/notifier.c:382 __inet_del_ifa+0x879/0x1020 net/ipv4/devinet.c:445 inet_del_ifa net/ipv4/devinet.c:482 [inline] inetdev_destroy net/ipv4/devinet.c:323 [inline] inetdev_event+0x5b6/0x1400 net/ipv4/devinet.c:1615 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] unregister_netdevice_many+0x1086/0x1930 net/core/dev.c:10990 default_device_exit_batch+0x9e6/0xa80 net/core/dev.c:11503 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x791/0xba0 net/core/net_namespace.c:640 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff88802e9de800 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of 256-byte region [ffff88802e9de800, ffff88802e9de900) The buggy address belongs to the physical page: page:ffffea0000ba7780 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2e9de head:ffffea0000ba7780 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea00005ddf00 dead000000000003 ffff888017441b40 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4266, tgid 4266 (syz-executor), ts 73105726513, free_ts 73024969938 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4328 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5614 alloc_slab_page+0x5d/0x160 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2c0 mm/slub.c:1997 ___slab_alloc+0xbc6/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc+0xa0/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] new_dir fs/proc/proc_sysctl.c:973 [inline] get_subdir fs/proc/proc_sysctl.c:1017 [inline] __register_sysctl_table+0x96c/0xe70 fs/proc/proc_sysctl.c:1379 __addrconf_sysctl_register+0x271/0x3e0 net/ipv6/addrconf.c:7150 addrconf_sysctl_register+0x15c/0x1b0 net/ipv6/addrconf.c:7197 ipv6_add_dev+0xbe0/0x1120 net/ipv6/addrconf.c:451 addrconf_notify+0x634/0xf40 net/ipv6/addrconf.c:3595 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] register_netdevice+0x1640/0x1ae0 net/core/dev.c:10237 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:317 [inline] nsim_create+0x35f/0x410 drivers/net/netdevsim/netdev.c:365 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc_lru+0x11a/0x2e0 mm/slub.c:3390 alloc_inode_sb include/linux/fs.h:3245 [inline] alloc_inode fs/inode.c:263 [inline] new_inode_pseudo+0x7e/0x1c0 fs/inode.c:1063 new_inode+0x25/0x1c0 fs/inode.c:1091 debugfs_get_inode fs/debugfs/inode.c:72 [inline] __debugfs_create_file+0x148/0x510 fs/debugfs/inode.c:432 nsim_bpf_init+0xe7/0x250 drivers/net/netdevsim/bpf.c:629 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:311 [inline] nsim_create+0x325/0x410 drivers/net/netdevsim/netdev.c:365 __nsim_dev_port_add+0x703/0xb70 drivers/net/netdevsim/dev.c:1396 nsim_dev_port_add_all+0x35/0xe0 drivers/net/netdevsim/dev.c:1454 nsim_drv_probe+0x841/0xb20 drivers/net/netdevsim/dev.c:1608 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2aa/0xc70 drivers/base/dd.c:639 Memory state around the buggy address: ffff88802e9de780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802e9de800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802e9de880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802e9de900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802e9de980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================