================================================================== BUG: KASAN: use-after-free in jfs_lazycommit+0x786/0xb60 fs/jfs/jfs_txnmgr.c:2770 Read of size 4 at addr ffff88801b7a4294 by task jfsCommit/277 CPU: 1 PID: 277 Comm: jfsCommit Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 jfs_lazycommit+0x786/0xb60 fs/jfs/jfs_txnmgr.c:2770 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 5340: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] jfs_fill_super+0xdc/0xad0 fs/jfs/super.c:500 mount_bdev+0x28a/0x3c0 fs/super.c:1411 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1541 do_new_mount+0x247/0xa40 fs/namespace.c:3034 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 4187: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 generic_shutdown_super+0x130/0x300 fs/super.c:475 kill_block_super+0x7c/0xe0 fs/super.c:1438 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x426/0x4d0 fs/namespace.c:1148 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:184 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:217 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:310 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 kvfree_call_rcu+0x105/0x7f0 kernel/rcu/tree.c:3600 tcf_chain_destroy net/sched/cls_api.c:419 [inline] __tcf_chain_put+0x600/0x7c0 net/sched/cls_api.c:576 tcf_chain_put net/sched/cls_api.c:582 [inline] tcf_get_next_chain net/sched/cls_api.c:947 [inline] tcf_block_flush_all_chains net/sched/cls_api.c:1015 [inline] __tcf_block_put+0x384/0x490 net/sched/cls_api.c:1179 ingress_destroy+0x75/0xb0 net/sched/sch_ingress.c:110 qdisc_destroy+0x115/0x390 net/sched/sch_generic.c:1029 qdisc_put net/sched/sch_generic.c:1048 [inline] shutdown_scheduler_queue net/sched/sch_generic.c:1101 [inline] dev_shutdown+0x494/0x700 net/sched/sch_generic.c:1411 unregister_netdevice_many+0xa59/0x1a40 net/core/dev.c:11153 unregister_netdevice_queue+0x2e1/0x320 net/core/dev.c:11093 unregister_netdevice include/linux/netdevice.h:3047 [inline] __tun_detach+0xdb7/0x1580 drivers/net/tun.c:686 tun_detach drivers/net/tun.c:702 [inline] tun_chr_close+0x109/0x1b0 drivers/net/tun.c:3454 __fput+0x212/0x8c0 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:184 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:217 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:310 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Second to last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 kvfree_call_rcu+0x105/0x7f0 kernel/rcu/tree.c:3600 drop_sysctl_table+0x359/0x4e0 fs/proc/proc_sysctl.c:1685 drop_sysctl_table+0x348/0x4e0 fs/proc/proc_sysctl.c:1688 unregister_sysctl_table+0x87/0x130 fs/proc/proc_sysctl.c:1723 __devinet_sysctl_unregister net/ipv4/devinet.c:2626 [inline] devinet_sysctl_unregister net/ipv4/devinet.c:2654 [inline] inetdev_event+0xce3/0x1350 net/ipv4/devinet.c:1619 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2074 [inline] call_netdevice_notifiers net/core/dev.c:2088 [inline] dev_change_name+0x676/0xc10 net/core/dev.c:1345 do_setlink+0x9e7/0x29d0 net/core/rtnetlink.c:2773 __rtnl_newlink net/core/rtnetlink.c:3464 [inline] rtnl_newlink+0x15bb/0x1920 net/core/rtnetlink.c:3586 rtnetlink_rcv_msg+0x7f1/0xf10 net/core/rtnetlink.c:5698 netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2519 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x78f/0x940 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] __sys_sendto+0x46d/0x620 net/socket.c:2073 __do_sys_sendto net/socket.c:2085 [inline] __se_sys_sendto net/socket.c:2081 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2081 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff88801b7a4200 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of 256-byte region [ffff88801b7a4200, ffff88801b7a4300) The buggy address belongs to the page: page:ffffea00006de900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1b7a4 head:ffffea00006de900 order:1 compound_mapcount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888016c41b40 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 4186, ts 54812535064, free_ts 21914701814 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x807/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] __kmalloc+0x11d/0x340 mm/slub.c:4408 kmalloc include/linux/slab.h:612 [inline] kzalloc include/linux/slab.h:738 [inline] new_dir fs/proc/proc_sysctl.c:959 [inline] get_subdir fs/proc/proc_sysctl.c:1004 [inline] __register_sysctl_table+0xa32/0x1240 fs/proc/proc_sysctl.c:1353 neigh_sysctl_register+0x9b2/0xa90 net/core/neighbour.c:3718 devinet_sysctl_register+0xa8/0x1f0 net/ipv4/devinet.c:2640 inetdev_init+0x28c/0x4d0 net/ipv4/devinet.c:277 inetdev_event+0x26f/0x1350 net/ipv4/devinet.c:1543 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2074 [inline] call_netdevice_notifiers net/core/dev.c:2088 [inline] register_netdevice+0x12a8/0x1720 net/core/dev.c:10454 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:317 [inline] nsim_create+0x32d/0x3e0 drivers/net/netdevsim/netdev.c:365 __nsim_dev_port_add+0x66e/0xa80 drivers/net/netdevsim/dev.c:1312 nsim_dev_port_add_all+0x37/0x100 drivers/net/netdevsim/dev.c:1372 nsim_dev_probe+0x75e/0x9d0 drivers/net/netdevsim/dev.c:1513 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] __kmalloc+0x189/0x340 mm/slub.c:4408 kmalloc include/linux/slab.h:612 [inline] tomoyo_realpath_from_path+0xed/0x5e0 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x23f/0x5d0 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x120 security/security.c:1398 vfs_getattr+0x26/0x3a0 fs/stat.c:157 vfs_statx+0x146/0x4c0 fs/stat.c:225 vfs_fstatat fs/stat.c:243 [inline] __do_sys_newfstatat fs/stat.c:411 [inline] __se_sys_newfstatat fs/stat.c:405 [inline] __x64_sys_newfstatat+0x15f/0x200 fs/stat.c:405 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff88801b7a4180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801b7a4200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801b7a4280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801b7a4300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801b7a4380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================