EXT4-fs error (device loop4): ext4_validate_block_bitmap:438: comm ext4lazyinit: bg 0: block 234: padding at end of block bitmap is not set ================================================================== BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:930 [inline] BUG: KASAN: use-after-free in enqueue_timer+0xa6/0x480 kernel/time/timer.c:611 Write of size 8 at addr ffff88811749e4c0 by task ext4lazyinit/4885 CPU: 0 PID: 4885 Comm: ext4lazyinit Not tainted 6.1.90-syzkaller-00129-g37391192a93a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x158/0x4e0 mm/kasan/report.c:427 kasan_report+0x13c/0x170 mm/kasan/report.c:531 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report_generic.c:356 hlist_add_head include/linux/list.h:930 [inline] enqueue_timer+0xa6/0x480 kernel/time/timer.c:611 internal_add_timer kernel/time/timer.c:640 [inline] __mod_timer+0x8d3/0xcf0 kernel/time/timer.c:1121 mod_timer+0x1f/0x30 kernel/time/timer.c:1172 ext4_update_super+0xa41/0xe50 fs/ext4/super.c:6043 ext4_commit_super+0xe3/0x4b0 fs/ext4/super.c:6062 ext4_handle_error+0x5e1/0x890 fs/ext4/super.c:678 __ext4_error+0x260/0x480 fs/ext4/super.c:778 ext4_validate_block_bitmap+0x106d/0x1400 ext4_read_block_bitmap_nowait+0x593/0x970 fs/ext4/balloc.c:548 ext4_mb_prefetch+0x46d/0x640 fs/ext4/mballoc.c:2588 ext4_run_li_request fs/ext4/super.c:3647 [inline] ext4_lazyinit_thread+0x5df/0x1650 fs/ext4/super.c:3773 kthread+0x26d/0x300 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Allocated by task 4821: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:379 [inline] __kasan_kmalloc+0x9c/0xb0 mm/kasan/common.c:388 kasan_kmalloc include/linux/kasan.h:212 [inline] kmalloc_trace+0x44/0xa0 mm/slab_common.c:1052 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:692 [inline] ext4_alloc_sbi fs/ext4/super.c:4264 [inline] ext4_fill_super+0x102/0x8460 fs/ext4/super.c:5638 get_tree_bdev+0x440/0x680 fs/super.c:1357 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5681 vfs_get_tree+0x88/0x290 fs/super.c:1564 do_new_mount+0x2ba/0xb30 fs/namespace.c:3051 path_mount+0x671/0x1070 fs/namespace.c:3381 do_mount fs/namespace.c:3394 [inline] __do_sys_mount fs/namespace.c:3602 [inline] __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3579 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3579 x64_sys_call+0x49d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 4792: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1745 [inline] slab_free_freelist_hook mm/slub.c:1771 [inline] slab_free mm/slub.c:3684 [inline] __kmem_cache_free+0x218/0x3b0 mm/slub.c:3697 kfree+0x7a/0xf0 mm/slab_common.c:1009 ext4_put_super+0x9e5/0xd60 fs/ext4/super.c:1312 generic_shutdown_super+0x14f/0x370 fs/super.c:503 kill_block_super+0x7e/0xe0 fs/super.c:1461 deactivate_locked_super+0xad/0x110 fs/super.c:334 deactivate_super+0xbe/0xf0 fs/super.c:365 cleanup_mnt+0x485/0x510 fs/namespace.c:1186 __cleanup_mnt+0x19/0x20 fs/namespace.c:1193 task_work_run+0x24d/0x2e0 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xbd5/0x2b80 kernel/exit.c:875 do_group_exit+0x21a/0x2d0 kernel/exit.c:1025 __do_sys_exit_group kernel/exit.c:1036 [inline] __se_sys_exit_group kernel/exit.c:1034 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1034 x64_sys_call+0x610/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88811749e000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1216 bytes inside of 4096-byte region [ffff88811749e000, ffff88811749f000) The buggy address belongs to the physical page: page:ffffea00045d2600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x117498 head:ffffea00045d2600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100043380 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 1821, tgid 1821 (syz-executor), ts 101280615620, free_ts 101208467380 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x213/0x220 mm/page_alloc.c:2590 prep_new_page+0x1b/0x110 mm/page_alloc.c:2597 get_page_from_freelist+0x27ea/0x2870 mm/page_alloc.c:4425 __alloc_pages+0x3a1/0x780 mm/page_alloc.c:5714 alloc_slab_page+0x6c/0xf0 allocate_slab mm/slub.c:1962 [inline] new_slab+0x90/0x3e0 mm/slub.c:2015 ___slab_alloc+0x6f9/0xb80 mm/slub.c:3203 __slab_alloc+0x5d/0xa0 mm/slub.c:3302 slab_alloc_node mm/slub.c:3387 [inline] __kmem_cache_alloc_node+0x1af/0x250 mm/slub.c:3460 kmalloc_trace+0x2a/0xa0 mm/slab_common.c:1047 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:692 [inline] snmp6_alloc_dev net/ipv6/addrconf.c:356 [inline] ipv6_add_dev+0x5dd/0x11a0 net/ipv6/addrconf.c:406 ipv6_find_idev net/ipv6/addrconf.c:491 [inline] inet6_rtm_newaddr+0x6b0/0x2780 net/ipv6/addrconf.c:4961 rtnetlink_rcv_msg+0x9a5/0xca0 net/core/rtnetlink.c:6121 netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2518 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6139 netlink_unicast_kernel net/netlink/af_netlink.c:1327 [inline] netlink_unicast+0x906/0xab0 net/netlink/af_netlink.c:1353 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1498 [inline] free_pcp_prepare mm/page_alloc.c:1572 [inline] free_unref_page_prepare+0x83d/0x850 mm/page_alloc.c:3498 free_unref_page+0xb2/0x5c0 mm/page_alloc.c:3594 free_the_page mm/page_alloc.c:798 [inline] __free_pages+0x61/0xf0 mm/page_alloc.c:5803 __free_slab+0xce/0x1a0 mm/slub.c:2039 free_slab mm/slub.c:2054 [inline] discard_slab mm/slub.c:2060 [inline] __unfreeze_partials+0x165/0x1a0 mm/slub.c:2609 put_cpu_partial+0xa9/0x100 mm/slub.c:2685 __slab_free+0x1c8/0x280 mm/slub.c:3561 do_slab_free mm/slub.c:3638 [inline] ___cache_free+0xc6/0xd0 mm/slub.c:3691 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0xc5/0x140 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x15a/0x180 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x24/0x80 mm/kasan/common.c:310 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:768 slab_alloc_node mm/slub.c:3421 [inline] __kmem_cache_alloc_node+0x191/0x250 mm/slub.c:3460 kmalloc_trace+0x2a/0xa0 mm/slab_common.c:1047 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:692 [inline] ref_tracker_alloc+0x138/0x450 lib/ref_tracker.c:85 __netdev_tracker_alloc include/linux/netdevice.h:4063 [inline] netdev_hold include/linux/netdevice.h:4092 [inline] netdev_queue_add_kobject net/core/net-sysfs.c:1659 [inline] netdev_queue_update_kobjects+0x18a/0x4a0 net/core/net-sysfs.c:1714 Memory state around the buggy address: ffff88811749e380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811749e400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88811749e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811749e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811749e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== EXT4-fs (loop4): Remounting filesystem read-only