================================================================== BUG: KASAN: use-after-free in ext4_htree_fill_tree+0x1066/0x10d0 fs/ext4/namei.c:1246 Read of size 1 at addr ffff88813013b365 by task syz-executor/2540 CPU: 1 PID: 2540 Comm: syz-executor 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+0x71/0x200 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:420 kasan_report+0x122/0x150 mm/kasan/report.c:524 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:348 ext4_htree_fill_tree+0x1066/0x10d0 fs/ext4/namei.c:1246 ext4_dx_readdir fs/ext4/dir.c:608 [inline] ext4_readdir+0x2d8a/0x3c10 fs/ext4/dir.c:145 iterate_dir+0x271/0x610 fs/readdir.c:-1 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0xe5/0x240 fs/readdir.c:354 __x64_sys_getdents64+0x7b/0x90 fs/readdir.c:354 x64_sys_call+0x15c/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:218 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: 0033:0x7fa285dbf753 Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 52 3e f8 ff 66 90 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 a8 ff ff ff f7 d8 RSP: 002b:00007fffba669308 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 000055557b4c34e0 RCX: 00007fa285dbf753 RDX: 0000000000008000 RSI: 000055557b4c34e0 RDI: 0000000000000005 RBP: 000055557b4c34b4 R08: 0000000000028b61 R09: 0000000000000000 R10: 00007fa285f7cca0 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 000055557b4c34b0 R15: 00007fffba66b5c0 Allocated by task 2404: 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_slab_alloc+0x72/0x80 mm/kasan/common.c:333 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:3382 [inline] slab_alloc mm/slub.c:3392 [inline] __kmem_cache_alloc_lru mm/slub.c:3399 [inline] kmem_cache_alloc+0x16e/0x330 mm/slub.c:3408 kmem_cache_zalloc include/linux/slab.h:689 [inline] __kernfs_new_node+0xdb/0x680 fs/kernfs/dir.c:614 kernfs_new_node+0x150/0x260 fs/kernfs/dir.c:690 __kernfs_create_file+0x4e/0x270 fs/kernfs/file.c:1050 sysfs_add_file_mode_ns+0x1ce/0x270 fs/sysfs/file.c:294 create_files fs/sysfs/group.c:64 [inline] internal_create_group+0x495/0xd00 fs/sysfs/group.c:148 internal_create_groups fs/sysfs/group.c:188 [inline] sysfs_create_groups+0x58/0x120 fs/sysfs/group.c:214 device_add_groups drivers/base/core.c:2753 [inline] device_add_attrs+0xdb/0x810 drivers/base/core.c:2901 device_add+0x5f1/0xef0 drivers/base/core.c:3649 netdev_register_kobject+0x179/0x320 net/core/net-sysfs.c:2009 register_netdevice+0xe3d/0x14a0 net/core/dev.c:10168 veth_newlink+0x592/0xbe0 drivers/net/veth.c:1745 rtnl_newlink_create net/core/rtnetlink.c:3422 [inline] __rtnl_newlink net/core/rtnetlink.c:3642 [inline] rtnl_newlink+0x14b9/0x2030 net/core/rtnetlink.c:3655 rtnetlink_rcv_msg+0x9f4/0xcf0 net/core/rtnetlink.c:6153 netlink_rcv_skb+0x1f2/0x440 net/netlink/af_netlink.c:2521 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6171 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x8ab/0xa30 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x8aa/0xbc0 net/netlink/af_netlink.c:1873 sock_sendmsg_nosec net/socket.c:716 [inline] __sock_sendmsg net/socket.c:728 [inline] __sys_sendto+0x464/0x5e0 net/socket.c:2143 __do_sys_sendto net/socket.c:2155 [inline] __se_sys_sendto net/socket.c:2151 [inline] __x64_sys_sendto+0xe5/0x100 net/socket.c:2151 x64_sys_call+0x83/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:45 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 310: 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:1750 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776 slab_free mm/slub.c:3712 [inline] kmem_cache_free+0x12d/0x300 mm/slub.c:3737 kernfs_put+0x310/0x480 fs/kernfs/dir.c:568 kernfs_remove_by_name_ns+0xea/0x160 fs/kernfs/dir.c:1668 kernfs_remove_by_name include/linux/kernfs.h:635 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0x105/0x2a0 fs/sysfs/group.c:288 sysfs_remove_groups+0x56/0xb0 fs/sysfs/group.c:312 device_remove_groups drivers/base/core.c:2760 [inline] device_remove_attrs+0x205/0x250 drivers/base/core.c:2980 device_del+0x69c/0xeb0 drivers/base/core.c:3885 netdev_unregister_kobject+0x186/0x250 net/core/net-sysfs.c:1981 unregister_netdevice_many+0x135b/0x1820 net/core/dev.c:10994 default_device_exit_batch+0x9b9/0xa50 net/core/dev.c:11480 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x62d/0xb00 net/core/net_namespace.c:604 process_one_work+0x71f/0xc40 kernel/workqueue.c:2302 worker_thread+0xa29/0x11f0 kernel/workqueue.c:2449 kthread+0x281/0x320 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff88813013b320 which belongs to the cache kernfs_node_cache of size 136 The buggy address is located 69 bytes inside of 136-byte region [ffff88813013b320, ffff88813013b3a8) The buggy address belongs to the physical page: page:ffffea0004c04ec0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88813013b898 pfn:0x13013b flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea0004649808 ffffea0004312988 ffff8881002aca80 raw: ffff88813013b898 000000000014000f 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 1430, tgid 1430 (syz-executor), ts 105002051891, free_ts 104102551158 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:1967 [inline] new_slab+0x98/0x3d0 mm/slub.c:2020 ___slab_alloc+0x6bd/0xb20 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] slab_alloc mm/slub.c:3392 [inline] __kmem_cache_alloc_lru mm/slub.c:3399 [inline] kmem_cache_alloc+0x1b0/0x330 mm/slub.c:3408 kmem_cache_zalloc include/linux/slab.h:689 [inline] __kernfs_new_node+0xdb/0x680 fs/kernfs/dir.c:614 kernfs_new_node+0x150/0x260 fs/kernfs/dir.c:690 __kernfs_create_file+0x4e/0x270 fs/kernfs/file.c:1050 sysfs_add_file_mode_ns+0x1ce/0x270 fs/sysfs/file.c:294 create_files fs/sysfs/group.c:64 [inline] internal_create_group+0x495/0xd00 fs/sysfs/group.c:148 internal_create_groups fs/sysfs/group.c:188 [inline] sysfs_create_groups+0x58/0x120 fs/sysfs/group.c:214 create_dir lib/kobject.c:68 [inline] kobject_add_internal+0x745/0xc20 lib/kobject.c:231 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:2044 free_slab mm/slub.c:2059 [inline] discard_slab mm/slub.c:2065 [inline] __unfreeze_partials+0x160/0x190 mm/slub.c:2614 put_cpu_partial+0xa9/0x100 mm/slub.c:2690 __slab_free+0x1c4/0x280 mm/slub.c:3589 do_slab_free mm/slub.c:3666 [inline] ___cache_free+0xbf/0xd0 mm/slub.c:3722 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:3382 [inline] __kmem_cache_alloc_node+0x192/0x2c0 mm/slub.c:3423 kmalloc_trace+0x29/0xb0 mm/slab_common.c:1028 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] kobject_uevent_env+0x287/0x730 lib/kobject_uevent.c:539 kobject_uevent+0x1d/0x30 lib/kobject_uevent.c:657 Memory state around the buggy address: ffff88813013b200: fb fb fb fc fc fc fc fc fc fc fc 00 00 00 00 00 ffff88813013b280: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc >ffff88813013b300: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb ^ ffff88813013b380: fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb ffff88813013b400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ================================================================== EXT4-fs error (device loop0): htree_dirblock_to_tree:1112: inode #2: block 20: comm syz-executor: bad entry in directory: inode out of bounds - offset=1024, inode=2033530174, rec_len=1012, size=1024 fake=0 EXT4-fs error (device loop0): htree_dirblock_to_tree:1112: inode #2: block 20: comm syz-executor: bad entry in directory: inode out of bounds - offset=1024, inode=2033530174, rec_len=1012, size=1024 fake=0 EXT4-fs error (device loop0): htree_dirblock_to_tree:1112: inode #2: block 20: comm syz-executor: bad entry in directory: inode out of bounds - offset=1024, inode=2033530174, rec_len=1012, size=1024 fake=0 EXT4-fs error (device loop0): htree_dirblock_to_tree:1112: inode #2: block 20: comm syz-executor: bad entry in directory: inode out of bounds - offset=1024, inode=2033530174, rec_len=1012, size=1024 fake=0 EXT4-fs error (device loop0): htree_dirblock_to_tree:1112: inode #2: block 20: comm syz-executor: bad entry in directory: inode out of bounds - offset=1024, inode=2033530174, rec_len=1012, size=1024 fake=0 EXT4-fs error (device loop0): htree_dirblock_to_tree:1112: inode #2: block 20: comm syz-executor: bad entry in directory: inode out of bounds - offset=1024, inode=2033530174, rec_len=1012, size=1024 fake=0 EXT4-fs error (device loop0): htree_dirblock_to_tree:1112: inode #2: block 20: comm syz-executor: bad entry in directory: inode out of bounds - offset=1024, inode=2033530174, rec_len=1012, size=1024 fake=0 EXT4-fs (loop0): unmounting filesystem.