================================================================== BUG: KASAN: use-after-free in ext4_htree_fill_tree+0x106b/0x10d0 fs/ext4/namei.c:1246 Read of size 1 at addr ffff88811ccf6365 by task syz-executor/2478 CPU: 0 PID: 2478 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0xf1/0x140 mm/kasan/report.c:444 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306 ext4_htree_fill_tree+0x106b/0x10d0 fs/ext4/namei.c:1246 ext4_dx_readdir fs/ext4/dir.c:609 [inline] ext4_readdir+0x2bfd/0x3a40 fs/ext4/dir.c:145 iterate_dir+0x260/0x600 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+0x592/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:218 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f3605890ad3 Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 72 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:00007ffe8b989ae8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 0000555578c5a4e0 RCX: 00007f3605890ad3 RDX: 0000000000008000 RSI: 0000555578c5a4e0 RDI: 0000000000000005 RBP: 0000555578c5a4b4 R08: 0000000000028b61 R09: 0000000000000000 R10: 00007f3605a4dca0 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 0000555578c5a4b0 R15: 00007ffe8b98bda0 Allocated by task 2165: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:433 [inline] __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:466 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550 slab_alloc_node mm/slub.c:3240 [inline] slab_alloc mm/slub.c:3250 [inline] kmem_cache_alloc+0xf7/0x260 mm/slub.c:3255 kmem_cache_zalloc include/linux/slab.h:737 [inline] __kernfs_new_node+0xdb/0x680 fs/kernfs/dir.c:593 kernfs_new_node+0x150/0x260 fs/kernfs/dir.c:669 __kernfs_create_file+0x4e/0x270 fs/kernfs/file.c:987 sysfs_add_file_mode_ns+0x29a/0x350 fs/sysfs/file.c:317 create_files fs/sysfs/group.c:64 [inline] internal_create_group+0x489/0xcf0 fs/sysfs/group.c:149 internal_create_groups fs/sysfs/group.c:189 [inline] sysfs_create_groups+0x58/0x120 fs/sysfs/group.c:215 device_add_groups drivers/base/core.c:2501 [inline] device_add_attrs+0x8c/0x700 drivers/base/core.c:2649 device_add+0x5e3/0xed0 drivers/base/core.c:3373 netdev_register_kobject+0x179/0x320 net/core/net-sysfs.c:2014 register_netdevice+0xdfa/0x13a0 net/core/dev.c:10405 macsec_newlink+0x594/0xcb0 drivers/net/macsec.c:4069 __rtnl_newlink net/core/rtnetlink.c:3524 [inline] rtnl_newlink+0x112d/0x17b0 net/core/rtnetlink.c:3572 rtnetlink_rcv_msg+0x9e4/0xb90 net/core/rtnetlink.c:5650 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2511 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5668 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x86a/0xb70 net/netlink/af_netlink.c:1922 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] __sys_sendto+0x423/0x580 net/socket.c:2063 __do_sys_sendto net/socket.c:2075 [inline] __se_sys_sendto net/socket.c:2071 [inline] __x64_sys_sendto+0xe5/0x100 net/socket.c:2071 x64_sys_call+0x178/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 319: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:365 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1749 slab_free mm/slub.c:3521 [inline] kmem_cache_free+0x100/0x320 mm/slub.c:3539 kernfs_put+0x310/0x480 fs/kernfs/dir.c:547 kernfs_remove_by_name_ns+0xea/0x160 fs/kernfs/dir.c:1595 kernfs_remove_by_name include/linux/kernfs.h:619 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0x105/0x2a0 fs/sysfs/group.c:289 sysfs_remove_groups+0x56/0xb0 fs/sysfs/group.c:313 device_remove_groups drivers/base/core.c:2508 [inline] device_remove_attrs+0x124/0x140 drivers/base/core.c:2714 device_del+0x68e/0xe90 drivers/base/core.c:3609 netdev_unregister_kobject+0x186/0x250 net/core/net-sysfs.c:1980 unregister_netdevice_many+0x1486/0x1990 net/core/dev.c:11177 default_device_exit_batch+0x330/0x390 net/core/dev.c:11683 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x602/0xad0 net/core/net_namespace.c:599 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff88811ccf6320 which belongs to the cache kernfs_node_cache of size 136 The buggy address is located 69 bytes inside of 136-byte region [ffff88811ccf6320, ffff88811ccf63a8) The buggy address belongs to the page: page:ffffea0004733d80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11ccf6 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea00046e9900 0000000900000003 ffff8881001c5e00 raw: 0000000000000000 0000000000140014 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 543, ts 62226326554, free_ts 60992916127 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605 prep_new_page+0x1c/0x110 mm/page_alloc.c:2611 get_page_from_freelist+0x2cc5/0x2d50 mm/page_alloc.c:4485 __alloc_pages+0x18f/0x440 mm/page_alloc.c:5795 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1932 [inline] new_slab+0xa1/0x4d0 mm/slub.c:1995 ___slab_alloc+0x381/0x810 mm/slub.c:3028 __slab_alloc+0x49/0x90 mm/slub.c:3115 slab_alloc_node mm/slub.c:3206 [inline] slab_alloc mm/slub.c:3250 [inline] kmem_cache_alloc+0x138/0x260 mm/slub.c:3255 kmem_cache_zalloc include/linux/slab.h:737 [inline] __kernfs_new_node+0xdb/0x680 fs/kernfs/dir.c:593 kernfs_new_node+0x150/0x260 fs/kernfs/dir.c:669 __kernfs_create_file+0x4e/0x270 fs/kernfs/file.c:987 sysfs_add_file_mode_ns+0x29a/0x350 fs/sysfs/file.c:317 create_files fs/sysfs/group.c:64 [inline] internal_create_group+0x489/0xcf0 fs/sysfs/group.c:149 internal_create_groups fs/sysfs/group.c:189 [inline] sysfs_create_groups+0x58/0x120 fs/sysfs/group.c:215 device_add_groups drivers/base/core.c:2501 [inline] device_add_attrs+0x155/0x700 drivers/base/core.c:2660 device_add+0x5e3/0xed0 drivers/base/core.c:3373 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1472 [inline] free_pcp_prepare mm/page_alloc.c:1544 [inline] free_unref_page_prepare+0x542/0x550 mm/page_alloc.c:3534 free_unref_page+0xa2/0x550 mm/page_alloc.c:3616 free_the_page mm/page_alloc.c:805 [inline] __free_pages+0x6c/0x100 mm/page_alloc.c:5871 __free_slab+0xe8/0x1e0 mm/slub.c:2020 free_slab mm/slub.c:2035 [inline] discard_slab mm/slub.c:2041 [inline] __unfreeze_partials+0x160/0x190 mm/slub.c:2527 put_cpu_partial+0xc6/0x120 mm/slub.c:2607 __slab_free+0x1d4/0x290 mm/slub.c:3390 do_slab_free mm/slub.c:3509 [inline] ___cache_free+0x104/0x120 mm/slub.c:3530 qlink_free+0x4d/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xf0 mm/kasan/common.c:443 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550 slab_alloc_node mm/slub.c:3240 [inline] slab_alloc mm/slub.c:3250 [inline] kmem_cache_alloc+0xf7/0x260 mm/slub.c:3255 kmem_cache_alloc_node include/linux/slab.h:489 [inline] __alloc_skb+0xe0/0x740 net/core/skbuff.c:416 alloc_skb include/linux/skbuff.h:1183 [inline] mld_newpack+0x13a/0x9d0 net/ipv6/mcast.c:1746 Memory state around the buggy address: ffff88811ccf6200: fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb ffff88811ccf6280: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff88811ccf6300: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811ccf6380: fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb ffff88811ccf6400: 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