EXT4-fs error (device loop0): ext4_add_entry:2484: inode #2: comm syz.0.385: Directory hole found for htree leaf block 0 ================================================================== 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 ffff88811b1484c0 by task syz.0.385/1893 CPU: 1 PID: 1893 Comm: syz.0.385 Not tainted 6.1.112-syzkaller-00017-gdefe0024cfb0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 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:6066 ext4_commit_super+0xe3/0x4b0 fs/ext4/super.c:6085 ext4_handle_error+0x5e1/0x890 fs/ext4/super.c:678 __ext4_error_inode+0x327/0x5e0 fs/ext4/super.c:810 __ext4_read_dirblock+0x1a9/0x8e0 ext4_add_entry+0x743/0xed0 fs/ext4/namei.c:2484 ext4_add_nondir+0x97/0x290 fs/ext4/namei.c:2843 ext4_mknod+0x37d/0x560 fs/ext4/namei.c:2923 vfs_mknod+0x472/0x500 fs/namei.c:3986 do_mknodat+0x36b/0x5c0 __do_sys_mknodat fs/namei.c:4064 [inline] __se_sys_mknodat fs/namei.c:4061 [inline] __x64_sys_mknodat+0xa9/0xc0 fs/namei.c:4061 x64_sys_call+0x6cd/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:260 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 RIP: 0033:0x7fa9ccb7e719 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007fa9cc9ff038 EFLAGS: 00000246 ORIG_RAX: 0000000000000103 RAX: ffffffffffffffda RBX: 00007fa9ccd35f80 RCX: 00007fa9ccb7e719 RDX: b0a54e68b1cd2fdb RSI: 0000000020000040 RDI: ffffffffffffff9c RBP: 00007fa9ccbf175e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000103 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa9ccd35f80 R15: 00007ffd59cddb08 Allocated by task 1584: 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:1033 kmalloc include/linux/slab.h:557 [inline] kzalloc include/linux/slab.h:693 [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:1368 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5681 vfs_get_tree+0x88/0x290 fs/super.c:1575 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 1539: 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:990 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:1472 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:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0xbd5/0x2b80 kernel/exit.c:877 do_group_exit+0x21a/0x2d0 kernel/exit.c:1027 __do_sys_exit_group kernel/exit.c:1038 [inline] __se_sys_exit_group kernel/exit.c:1036 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036 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 ffff88811b148000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1216 bytes inside of 4096-byte region [ffff88811b148000, ffff88811b149000) The buggy address belongs to the physical page: page:ffffea00046c5200 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88811b14a000 pfn:0x11b148 head:ffffea00046c5200 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 ffffea000439e208 ffffea000439b408 ffff888100043380 raw: ffff88811b14a000 0000000000040002 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 884, tgid 884 (syz-executor), ts 60036910955, free_ts 56772224846 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+0x2980/0x2a10 mm/page_alloc.c:4439 __alloc_pages+0x234/0x610 mm/page_alloc.c:5728 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 __do_kmalloc_node mm/slab_common.c:937 [inline] __kmalloc_node_track_caller+0xa2/0x1e0 mm/slab_common.c:958 kmemdup+0x29/0x60 mm/util.c:134 _Z7kmemdupPKvU17pass_object_size0mj include/linux/fortify-string.h:585 [inline] __addrconf_sysctl_register+0xad/0x3e0 net/ipv6/addrconf.c:7132 addrconf_sysctl_register+0x141/0x1a0 net/ipv6/addrconf.c:7197 ipv6_add_dev+0xbd7/0x11a0 net/ipv6/addrconf.c:453 addrconf_notify+0x6d2/0xe10 net/ipv6/addrconf.c:3601 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0x8c/0xf0 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:1498 [inline] free_pcp_prepare mm/page_alloc.c:1572 [inline] free_unref_page_prepare+0x83d/0x850 mm/page_alloc.c:3511 free_unref_page+0xb2/0x5c0 mm/page_alloc.c:3607 free_the_page mm/page_alloc.c:798 [inline] __free_pages+0x61/0xf0 mm/page_alloc.c:5817 __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+0x18a/0x2d0 mm/slub.c:3466 __alloc_skb+0xcc/0x2d0 net/core/skbuff.c:505 alloc_skb include/linux/skbuff.h:1290 [inline] alloc_skb_with_frags+0xa6/0x680 net/core/skbuff.c:6162 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2753 Memory state around the buggy address: ffff88811b148380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811b148400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88811b148480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811b148500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811b148580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== EXT4-fs error (device loop0): ext4_add_entry:2484: inode #2: comm syz.0.385: Directory hole found for htree leaf block 0