BUG: KASAN: slab-out-of-bounds in ext4_htree_fill_tree+0x10f0/0x1160 fs/ext4/namei.c:1246 Read of size 1 at addr ffff88811b192d1b by task syz-executor/464 CPU: 0 PID: 464 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 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+0x10f0/0x1160 fs/ext4/namei.c:1246 ext4_dx_readdir fs/ext4/dir.c:608 [inline] ext4_readdir+0x2f80/0x3e10 fs/ext4/dir.c:145 iterate_dir+0x271/0x610 fs/readdir.c:-1 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0xf2/0x250 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:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3e4d9bfd73 Code: c7 c0 e8 ff ff ff 64 c7 00 16 00 00 00 31 c0 eb 9e e8 81 9b fd ff 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 e8 ff ff ff f7 d8 RSP: 002b:00007ffcb4c22068 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 0000555566293910 RCX: 00007f3e4d9bfd73 RDX: 0000000000008000 RSI: 0000555566293940 RDI: 0000000000000005 RBP: 0000555566293940 R08: 0000000000028701 R09: 0000000000000001 R10: 00007f3e4db93ca0 R11: 0000000000000293 R12: 0000555566293914 R13: ffffffffffffffe8 R14: 0000000000000010 R15: 0000000000000001 Allocated by task 464: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:380 [inline] __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389 kasan_kmalloc include/linux/kasan.h:212 [inline] __do_kmalloc_node mm/slab_common.c:938 [inline] __kmalloc_node_track_caller+0xb1/0x1e0 mm/slab_common.c:958 kmalloc_reserve net/core/skbuff.c:449 [inline] pskb_expand_head+0x1b0/0x1210 net/core/skbuff.c:1851 netlink_trim+0x193/0x230 net/netlink/af_netlink.c:1300 netlink_broadcast+0x6e/0x1180 net/netlink/af_netlink.c:1501 nlmsg_multicast include/net/netlink.h:1071 [inline] nlmsg_notify+0xe6/0x1a0 net/netlink/af_netlink.c:2564 rtnl_notify net/core/rtnetlink.c:796 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:3990 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4005 [inline] rtmsg_ifinfo+0xea/0x130 net/core/rtnetlink.c:4011 register_netdevice+0x1273/0x1530 net/core/dev.c:10215 register_netdev+0x3e/0x50 net/core/dev.c:10294 loopback_net_init+0x74/0x150 drivers/net/loopback.c:220 ops_init+0x1c8/0x4a0 net/core/net_namespace.c:138 setup_net+0x4b4/0xcc0 net/core/net_namespace.c:335 copy_net_ns+0x355/0x5c0 net/core/net_namespace.c:481 create_new_namespaces+0x3a2/0x660 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x120/0x170 kernel/nsproxy.c:226 ksys_unshare+0x4ba/0x7c0 kernel/fork.c:3415 __do_sys_unshare kernel/fork.c:3486 [inline] __se_sys_unshare kernel/fork.c:3484 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3484 x64_sys_call+0x767/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:273 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 464: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x31/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:242 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:250 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+0xb7/0x1b0 mm/slub.c:3728 kfree+0x6f/0xf0 mm/slab_common.c:990 skb_free_head net/core/skbuff.c:765 [inline] skb_release_data+0x63f/0x890 net/core/skbuff.c:794 skb_release_all net/core/skbuff.c:859 [inline] __kfree_skb net/core/skbuff.c:873 [inline] consume_skb+0xab/0x1f0 net/core/skbuff.c:1038 netlink_broadcast+0x1084/0x1180 net/netlink/af_netlink.c:1522 nlmsg_multicast include/net/netlink.h:1071 [inline] nlmsg_notify+0xe6/0x1a0 net/netlink/af_netlink.c:2564 rtnl_notify net/core/rtnetlink.c:796 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:3990 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4005 [inline] rtmsg_ifinfo+0xea/0x130 net/core/rtnetlink.c:4011 register_netdevice+0x1273/0x1530 net/core/dev.c:10215 register_netdev+0x3e/0x50 net/core/dev.c:10294 loopback_net_init+0x74/0x150 drivers/net/loopback.c:220 ops_init+0x1c8/0x4a0 net/core/net_namespace.c:138 setup_net+0x4b4/0xcc0 net/core/net_namespace.c:335 copy_net_ns+0x355/0x5c0 net/core/net_namespace.c:481 create_new_namespaces+0x3a2/0x660 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x120/0x170 kernel/nsproxy.c:226 ksys_unshare+0x4ba/0x7c0 kernel/fork.c:3415 __do_sys_unshare kernel/fork.c:3486 [inline] __se_sys_unshare kernel/fork.c:3484 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3484 x64_sys_call+0x767/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:273 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88811b192000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1307 bytes to the right of 2048-byte region [ffff88811b192000, ffff88811b192800) The buggy address belongs to the physical page: page:ffffea00046c6400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11b190 head:ffffea00046c6400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 dead000000000122 ffff888100043200 raw: 0000000000000000 0000000000080008 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 464, tgid 464 (syz-executor), ts 46878920928, free_ts 46773039619 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+0x2d12/0x2d80 mm/page_alloc.c:4554 __alloc_pages+0x1d9/0x480 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] __kmem_cache_alloc_node+0x203/0x2c0 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] ipv6_add_dev+0x10e/0x1230 net/ipv6/addrconf.c:383 addrconf_notify+0x6d5/0xe40 net/ipv6/addrconf.c:3621 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xa1/0x110 kernel/notifier.c:455 call_netdevice_notifiers_info net/core/dev.c:2009 [inline] call_netdevice_notifiers_extack net/core/dev.c:2047 [inline] call_netdevice_notifiers+0x119/0x190 net/core/dev.c:2061 register_netdevice+0x1173/0x1530 net/core/dev.c:10201 register_netdev+0x3e/0x50 net/core/dev.c:10294 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+0x95/0x540 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:311 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 __do_kmalloc_node mm/slab_common.c:937 [inline] __kmalloc+0xa1/0x1e0 mm/slab_common.c:951 kmalloc include/linux/slab.h:568 [inline] inotify_handle_inode_event+0x18f/0x4e0 fs/notify/inotify/inotify_fsnotify.c:96 fsnotify_handle_inode_event fs/notify/fsnotify.c:282 [inline] fsnotify_handle_event fs/notify/fsnotify.c:337 [inline] send_to_group fs/notify/fsnotify.c:385 [inline] fsnotify+0x1ba1/0x1f10 fs/notify/fsnotify.c:591 Memory state around the buggy address: ffff88811b192c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811b192c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88811b192d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88811b192d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811b192e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== EXT4-fs error (device loop2): __ext4_get_inode_loc:4515: comm syz-executor: Invalid inode table block 14875662660405297151 in block_group 0 EXT4-fs error (device loop2) in ext4_reserve_inode_write:5930: Corrupt filesystem EXT4-fs error (device loop2): ext4_dirty_inode:6134: inode #2: comm syz-executor: mark_inode_dirty error EXT4-fs (loop2): unmounting filesystem.