loop3: detected capacity change from 0 to 1024 EXT4-fs error (device loop3): ext4_validate_block_bitmap:438: comm syz.3.3648: bg 0: block 10: 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+0xae/0x480 kernel/time/timer.c:611 Write of size 8 at addr ffff8881135884c0 by task syz.3.3648/14354 CPU: 1 PID: 14354 Comm: syz.3.3648 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x71/0x1e0 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:418 kasan_report+0x122/0x150 mm/kasan/report.c:522 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report_generic.c:356 hlist_add_head include/linux/list.h:930 [inline] enqueue_timer+0xae/0x480 kernel/time/timer.c:611 __mod_timer+0x79f/0xb30 kernel/time/timer.c:-1 mod_timer+0x1f/0x30 kernel/time/timer.c:1172 ext4_update_super+0xa54/0xe40 fs/ext4/super.c:6068 ext4_commit_super+0xe3/0x4b0 fs/ext4/super.c:6087 ext4_handle_error+0x5c8/0x860 fs/ext4/super.c:678 __ext4_error+0x214/0x400 fs/ext4/super.c:779 ext4_validate_block_bitmap+0x79e/0x870 fs/ext4/balloc.c:-1 ext4_read_block_bitmap_nowait+0x5dd/0x970 fs/ext4/balloc.c:548 ext4_mb_prefetch+0x440/0x620 fs/ext4/mballoc.c:2587 ext4_mb_regular_allocator+0x94c/0x3570 fs/ext4/mballoc.c:2741 ext4_mb_new_blocks+0xc76/0x4210 fs/ext4/mballoc.c:5765 ext4_new_meta_blocks+0x151/0x3a0 fs/ext4/balloc.c:739 ext4_ext_grow_indepth fs/ext4/extents.c:1331 [inline] ext4_ext_create_new_leaf fs/ext4/extents.c:1437 [inline] ext4_ext_insert_extent+0x1048/0x4700 fs/ext4/extents.c:2105 ext4_ext_map_blocks+0x144d/0x6060 fs/ext4/extents.c:4361 ext4_map_blocks+0x9cb/0x1b60 fs/ext4/inode.c:679 ext4_getblk+0x1c1/0x6d0 fs/ext4/inode.c:890 ext4_bread+0x2b/0x170 fs/ext4/inode.c:946 ext4_quota_write+0x230/0x550 fs/ext4/super.c:7188 write_blk fs/quota/quota_tree.c:70 [inline] find_free_dqentry+0x6a3/0xc70 fs/quota/quota_tree.c:318 do_insert_tree+0x757/0x1060 fs/quota/quota_tree.c:400 do_insert_tree+0xa3f/0x1060 fs/quota/quota_tree.c:402 do_insert_tree+0xa3f/0x1060 fs/quota/quota_tree.c:402 do_insert_tree+0xa3f/0x1060 fs/quota/quota_tree.c:402 dq_insert_tree fs/quota/quota_tree.c:432 [inline] qtree_write_dquot+0x4a6/0x5c0 fs/quota/quota_tree.c:451 v2_write_dquot+0x130/0x1a0 fs/quota/quota_v2.c:361 dquot_acquire+0x30c/0x560 fs/quota/dquot.c:472 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6797 dqget+0xad0/0xf60 fs/quota/dquot.c:988 __dquot_initialize+0x3c7/0xc20 fs/quota/dquot.c:1517 dquot_initialize+0x1a/0x20 fs/quota/dquot.c:1579 ext4_process_orphan+0x59/0x320 fs/ext4/orphan.c:329 ext4_orphan_cleanup+0xb02/0x1210 fs/ext4/orphan.c:474 __ext4_fill_super fs/ext4/super.c:5522 [inline] ext4_fill_super+0x73e6/0x7930 fs/ext4/super.c:5653 get_tree_bdev+0x444/0x680 fs/super.c:1368 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5683 vfs_get_tree+0x9a/0x270 fs/super.c:1575 do_new_mount+0x25a/0xa20 fs/namespace.c:3063 path_mount+0x675/0x1010 fs/namespace.c:3393 do_mount fs/namespace.c:3406 [inline] __do_sys_mount fs/namespace.c:3614 [inline] __se_sys_mount+0x318/0x380 fs/namespace.c:3591 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3591 x64_sys_call+0x65d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc80cf903ca Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc80dd98e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fc80dd98ef0 RCX: 00007fc80cf903ca RDX: 0000200000000140 RSI: 0000200000000040 RDI: 00007fc80dd98eb0 RBP: 0000200000000140 R08: 00007fc80dd98ef0 R09: 0000000001018e58 R10: 0000000001018e58 R11: 0000000000000246 R12: 0000200000000040 R13: 00007fc80dd98eb0 R14: 00000000000005fe R15: 0000200000000000 Allocated by task 13821: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:379 [inline] __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:388 kasan_kmalloc include/linux/kasan.h:212 [inline] kmalloc_trace+0x40/0xb0 mm/slab_common.c:1033 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] ext4_alloc_sbi fs/ext4/super.c:4260 [inline] ext4_fill_super+0x107/0x7930 fs/ext4/super.c:5640 get_tree_bdev+0x444/0x680 fs/super.c:1368 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5683 vfs_get_tree+0x9a/0x270 fs/super.c:1575 do_new_mount+0x25a/0xa20 fs/namespace.c:3063 path_mount+0x675/0x1010 fs/namespace.c:3393 do_mount fs/namespace.c:3406 [inline] __do_sys_mount fs/namespace.c:3614 [inline] __se_sys_mount+0x318/0x380 fs/namespace.c:3591 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3591 x64_sys_call+0x65d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 6230: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x31/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x132/0x180 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+0xc2/0x190 mm/slub.c:1771 slab_free mm/slub.c:3686 [inline] __kmem_cache_free+0xb7/0x1b0 mm/slub.c:3702 kfree+0x6f/0xf0 mm/slab_common.c:990 ext4_put_super+0x9b6/0xac0 fs/ext4/super.c:1313 generic_shutdown_super+0x15f/0x370 fs/super.c:503 kill_block_super+0x7f/0xf0 fs/super.c:1472 deactivate_locked_super+0xb5/0x120 fs/super.c:334 deactivate_super+0xaf/0xe0 fs/super.c:365 cleanup_mnt+0x45f/0x4e0 fs/namespace.c:1182 __cleanup_mnt+0x19/0x20 fs/namespace.c:1189 task_work_run+0x1db/0x240 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0xa25/0x2650 kernel/exit.c:886 do_group_exit+0x210/0x2d0 kernel/exit.c:1028 __do_sys_exit_group kernel/exit.c:1039 [inline] __se_sys_exit_group kernel/exit.c:1037 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1037 x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888113588000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1216 bytes inside of 4096-byte region [ffff888113588000, ffff888113589000) The buggy address belongs to the physical page: page:ffffea00044d6200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x113588 head:ffffea00044d6200 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 ffffea0004c85800 dead000000000002 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 285, tgid 285 (syz-executor), ts 27600522838, free_ts 27598175524 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2643 prep_new_page+0x1c/0x110 mm/page_alloc.c:2650 get_page_from_freelist+0x2c7b/0x2cf0 mm/page_alloc.c:4554 __alloc_pages+0x1c3/0x450 mm/page_alloc.c:5868 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1962 [inline] new_slab+0x98/0x3d0 mm/slub.c:2015 ___slab_alloc+0x6f6/0xb50 mm/slub.c:3203 __slab_alloc+0x5e/0xa0 mm/slub.c:3302 slab_alloc_node mm/slub.c:3387 [inline] __kmem_cache_alloc_node+0x203/0x2c0 mm/slub.c:3462 __do_kmalloc_node mm/slab_common.c:937 [inline] __kmalloc_node_track_caller+0xa0/0x1e0 mm/slab_common.c:958 kmemdup+0x2b/0x60 mm/util.c:134 kmemdup include/linux/fortify-string.h:585 [inline] __devinet_sysctl_register+0xad/0x320 net/ipv4/devinet.c:2601 devinet_sysctl_register+0x169/0x1e0 net/ipv4/devinet.c:2653 inetdev_init+0x2d1/0x510 net/ipv4/devinet.c:280 inetdev_event+0x1f8/0x10e0 net/ipv4/devinet.c:1548 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xa1/0x110 kernel/notifier.c:455 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1551 [inline] free_pcp_prepare mm/page_alloc.c:1625 [inline] free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3589 free_unref_page+0x8f/0x530 mm/page_alloc.c:3687 free_the_page mm/page_alloc.c:836 [inline] __free_pages+0x67/0x100 mm/page_alloc.c:5957 __free_slab+0xca/0x1a0 mm/slub.c:2039 free_slab mm/slub.c:2054 [inline] discard_slab mm/slub.c:2060 [inline] __unfreeze_partials+0x160/0x190 mm/slub.c:2609 put_cpu_partial+0xa9/0x100 mm/slub.c:2685 __slab_free+0x1c4/0x280 mm/slub.c:3563 do_slab_free mm/slub.c:3640 [inline] ___cache_free+0xbf/0xd0 mm/slub.c:3696 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0xc6/0x140 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x14a/0x170 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+0x4f/0x2d0 mm/slab.h:768 slab_alloc_node mm/slub.c:3421 [inline] __kmem_cache_alloc_node+0x192/0x2c0 mm/slub.c:3462 kmalloc_trace+0x29/0xb0 mm/slab_common.c:1028 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] ref_tracker_alloc+0x139/0x430 lib/ref_tracker.c:85 __netdev_tracker_alloc include/linux/netdevice.h:4085 [inline] netdev_hold include/linux/netdevice.h:4114 [inline] netdev_queue_add_kobject net/core/net-sysfs.c:1657 [inline] netdev_queue_update_kobjects+0x185/0x470 net/core/net-sysfs.c:1712 Memory state around the buggy address: ffff888113588380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888113588400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888113588480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888113588500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888113588580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== EXT4-fs error (device loop3): ext4_acquire_dquot:6801: comm syz.3.3648: Failed to acquire dquot type 0 EXT4-fs error (device loop3): ext4_acquire_dquot:6801: comm syz.3.3648: Failed to acquire dquot type 0 EXT4-fs error (device loop3): ext4_free_blocks:6210: comm syz.3.3648: Freeing blocks not in datazone - block = 0, count = 4096 EXT4-fs error (device loop3): ext4_acquire_dquot:6801: comm syz.3.3648: Failed to acquire dquot type 0 EXT4-fs (loop3): 1 orphan inode deleted EXT4-fs (loop3): mounted filesystem without journal. Quota mode: writeback. syz.3.3648 (14354) used greatest stack depth: 19376 bytes left