================================================================== BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x753/0xa60 fs/jfs/jfs_txnmgr.c:2735 Read of size 4 at addr ffff888077de7494 by task jfsCommit/111 CPU: 0 PID: 111 Comm: jfsCommit Not tainted 6.6.94-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xac/0x230 mm/kasan/report.c:475 kasan_report+0x117/0x150 mm/kasan/report.c:588 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 9287: 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:3366 do_mount fs/namespace.c:3706 [inline] __do_sys_mount fs/namespace.c:3915 [inline] __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3892 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 7544: 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:1806 [inline] slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1832 slab_free mm/slub.c:3816 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3829 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+0xb1/0x140 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:3448 drop_sysctl_table+0x356/0x4b0 fs/proc/proc_sysctl.c:1511 drop_sysctl_table+0x36d/0x4b0 fs/proc/proc_sysctl.c:1514 unregister_sysctl_table+0x41/0x60 fs/proc/proc_sysctl.c:1532 neigh_sysctl_unregister+0x78/0xa0 net/core/neighbour.c:3885 addrconf_sysctl_unregister net/ipv6/addrconf.c:7246 [inline] addrconf_ifdown+0x1591/0x1880 net/ipv6/addrconf.c:3984 addrconf_notify+0x6c6/0x1010 net/ipv6/addrconf.c:-1 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:11074 unregister_netdevice_many net/core/dev.c:11130 [inline] default_device_exit_batch+0x9cb/0xa60 net/core/dev.c:11608 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 The buggy address belongs to the object at ffff888077de7400 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of freed 256-byte region [ffff888077de7400, ffff888077de7500) The buggy address belongs to the physical page: page:ffffea0001df7980 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x77de6 head:ffffea0001df7980 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017841b40 ffffea0000a16600 dead000000000002 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 5783, tgid 5783 (syz-executor), ts 85577565696, free_ts 85449590824 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:1876 allocate_slab mm/slub.c:2023 [inline] new_slab+0x87/0x2e0 mm/slub.c:2076 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230 __slab_alloc mm/slub.c:3329 [inline] __slab_alloc_node mm/slub.c:3382 [inline] slab_alloc_node mm/slub.c:3475 [inline] __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524 __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:965 [inline] get_subdir fs/proc/proc_sysctl.c:1009 [inline] sysctl_mkdir_p fs/proc/proc_sysctl.c:1304 [inline] __register_sysctl_table+0xac9/0x1240 fs/proc/proc_sysctl.c:1385 mpls_dev_sysctl_register+0x1ed/0x2e0 net/mpls/af_mpls.c:1406 mpls_add_dev net/mpls/af_mpls.c:1462 [inline] mpls_dev_notify+0x357/0x7a0 net/mpls/af_mpls.c:1602 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:10301 wg_newlink+0x48a/0x720 drivers/net/wireguard/device.c:373 rtnl_newlink_create net/core/rtnetlink.c:3517 [inline] __rtnl_newlink net/core/rtnetlink.c:3737 [inline] rtnl_newlink+0x14d0/0x2020 net/core/rtnetlink.c:3750 rtnetlink_rcv_msg+0x7c7/0xf10 net/core/rtnetlink.c:6475 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:3722 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:3485 [inline] __kmem_cache_alloc_node+0x13e/0x260 mm/slub.c:3524 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] ref_tracker_alloc+0x134/0x460 lib/ref_tracker.c:203 register_netdevice+0x149a/0x1ae0 net/core/dev.c:10288 veth_newlink+0x7bb/0xc30 drivers/net/veth.c:1902 rtnl_newlink_create net/core/rtnetlink.c:3517 [inline] __rtnl_newlink net/core/rtnetlink.c:3737 [inline] rtnl_newlink+0x14d0/0x2020 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:2537 netlink_unicast_kernel net/netlink/af_netlink.c:1323 [inline] netlink_unicast+0x750/0x8c0 net/netlink/af_netlink.c:1349 Memory state around the buggy address: ffff888077de7380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888077de7400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888077de7480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888077de7500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888077de7580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================