================================================================== BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x77a/0xaa0 fs/jfs/jfs_txnmgr.c:2736 Read of size 4 at addr ffff888026af7494 by task jfsCommit/115 CPU: 0 PID: 115 Comm: jfsCommit Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xa8/0x210 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 jfs_lazycommit+0x77a/0xaa0 fs/jfs/jfs_txnmgr.c:2736 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 8503: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] jfs_fill_super+0xe0/0xb00 fs/jfs/super.c:495 mount_bdev+0x21c/0x2c0 fs/super.c:1654 legacy_get_tree+0xea/0x180 fs/fs_context.c:662 vfs_get_tree+0x8c/0x280 fs/super.c:1775 do_new_mount+0x24a/0xa60 fs/namespace.c:3412 do_mount fs/namespace.c:3780 [inline] __do_sys_mount fs/namespace.c:3989 [inline] __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3966 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 6414: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1833 [inline] slab_free_freelist_hook+0x154/0x240 mm/slub.c:1859 slab_free mm/slub.c:3853 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3866 generic_shutdown_super+0x134/0x2b0 fs/super.c:690 kill_block_super+0x44/0x90 fs/super.c:1671 deactivate_locked_super+0x9c/0x210 fs/super.c:479 cleanup_mnt+0x3d7/0x460 fs/namespace.c:1259 task_work_run+0x1d4/0x260 kernel/task_work.c:245 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:180 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213 __syscall_exit_to_user_mode_work kernel/entry/common.c:294 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:305 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2721 [inline] call_rcu+0x153/0x900 kernel/rcu/tree.c:2837 free_fib_info net/ipv4/fib_semantics.c:257 [inline] fib_info_put include/net/ip_fib.h:587 [inline] fib_release_info+0x686/0x740 net/ipv4/fib_semantics.c:283 fib_table_flush+0xc9a/0x12d0 net/ipv4/fib_trie.c:2075 fib_flush net/ipv4/fib_frontend.c:195 [inline] fib_disable_ip+0xf8/0x170 net/ipv4/fib_frontend.c:1440 fib_netdev_event+0x31f/0x490 net/ipv4/fib_frontend.c:-1 notifier_call_chain+0x18f/0x380 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2077 [inline] call_netdevice_notifiers net/core/dev.c:2091 [inline] dev_close_many+0x2a6/0x410 net/core/dev.c:1632 unregister_netdevice_many_notify+0x4bf/0x1910 net/core/dev.c:11198 unregister_netdevice_many net/core/dev.c:11281 [inline] default_device_exit_batch+0x5e3/0x670 net/core/dev.c:11872 ops_exit_list net/core/net_namespace.c:178 [inline] cleanup_net+0x785/0xb00 net/core/net_namespace.c:656 process_one_work kernel/workqueue.c:2657 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815 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 ffff888026af7400 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of freed 256-byte region [ffff888026af7400, ffff888026af7500) The buggy address belongs to the physical page: page:ffffea00009abd80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x26af6 head:ffffea00009abd80 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888018c41b40 ffffea00008a0c80 dead000000000005 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 5790, tgid 5790 (syz-executor), ts 88218612710, free_ts 88148205119 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582 prep_new_page mm/page_alloc.c:1589 [inline] get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501 alloc_slab_page+0x5d/0x180 mm/slub.c:1903 allocate_slab mm/slub.c:2050 [inline] new_slab+0x87/0x2d0 mm/slub.c:2103 ___slab_alloc+0xc5c/0x12f0 mm/slub.c:3275 __slab_alloc mm/slub.c:3361 [inline] __slab_alloc_node mm/slub.c:3414 [inline] slab_alloc_node mm/slub.c:3508 [inline] __kmem_cache_alloc_node+0x122/0x260 mm/slub.c:3557 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0xa7/0x240 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:721 [inline] fib_create_info+0xa8d/0x2390 net/ipv4/fib_semantics.c:1493 fib_table_insert+0xc6/0x1b00 net/ipv4/fib_trie.c:1215 fib_magic+0x2ce/0x3b0 net/ipv4/fib_frontend.c:1118 fib_add_ifaddr+0x376/0x5d0 net/ipv4/fib_frontend.c:1155 fib_netdev_event+0x389/0x490 net/ipv4/fib_frontend.c:1500 notifier_call_chain+0x18f/0x380 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2077 [inline] call_netdevice_notifiers net/core/dev.c:2091 [inline] __dev_notify_flags+0x1ab/0x310 net/core/dev.c:8826 dev_change_flags+0xde/0x1a0 net/core/dev.c:8864 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1182 [inline] free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2459 __slab_free+0x35a/0x400 mm/slub.c:3759 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6a/0x4d0 mm/slab.h:770 slab_alloc_node mm/slub.c:3518 [inline] __kmem_cache_alloc_node+0x197/0x260 mm/slub.c:3557 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node+0xa6/0x240 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] kvmalloc_node+0x70/0x180 mm/util.c:634 kvmalloc include/linux/slab.h:738 [inline] groups_alloc kernel/groups.c:18 [inline] __do_sys_setgroups kernel/groups.c:208 [inline] __se_sys_setgroups+0xec/0x410 kernel/groups.c:198 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff888026af7380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888026af7400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888026af7480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888026af7500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888026af7580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================