================================================================== BUG: KASAN: slab-out-of-bounds in ext4_htree_fill_tree+0x1066/0x10d0 fs/ext4/namei.c:1221 Read of size 1 at addr ffff888111a06a67 by task syz-executor/466 CPU: 0 PID: 466 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0xe2/0x130 mm/kasan/report.c:452 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306 ext4_htree_fill_tree+0x1066/0x10d0 fs/ext4/namei.c:1221 ext4_dx_readdir fs/ext4/dir.c:601 [inline] ext4_readdir+0x2b45/0x39b0 fs/ext4/dir.c:145 iterate_dir+0x260/0x570 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 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fb57f29d0d3 Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 52 43 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:00007fffa1db9108 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 000055557abc34e0 RCX: 00007fb57f29d0d3 RDX: 0000000000008000 RSI: 000055557abc34e0 RDI: 0000000000000005 RBP: 000055557abc34b4 R08: 0000000000028b61 R09: 0000000000000000 R10: 00007fb57f3f7ca0 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 000055557abc34b0 R15: 00007fffa1dbb3b0 Allocated by task 448: 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:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] __kmalloc+0x1a7/0x330 mm/slub.c:4038 kmalloc include/linux/slab.h:560 [inline] kzalloc include/linux/slab.h:667 [inline] ops_init+0x89/0x4a0 net/core/net_namespace.c:134 setup_net+0x36d/0xb50 net/core/net_namespace.c:345 copy_net_ns+0x314/0x520 net/core/net_namespace.c:486 create_new_namespaces+0x3a2/0x650 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x120/0x170 kernel/nsproxy.c:231 ksys_unshare+0x4ac/0x7d0 kernel/fork.c:3156 __do_sys_unshare kernel/fork.c:3224 [inline] __se_sys_unshare kernel/fork.c:3222 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3222 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 7: 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:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kfree+0xc0/0x270 mm/slub.c:4196 ops_free net/core/net_namespace.c:164 [inline] ops_free_list net/core/net_namespace.c:199 [inline] cleanup_net+0x786/0xb70 net/core/net_namespace.c:613 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13b0 kernel/workqueue.c:2447 kthread+0x346/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 The buggy address belongs to the object at ffff888111a06800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 103 bytes to the right of 512-byte region [ffff888111a06800, ffff888111a06a00) The buggy address belongs to the page: page:ffffea0004468100 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111a04 head:ffffea0004468100 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100043080 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 448, ts 42027620160, free_ts 41935444634 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5370 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc_track_caller+0x1ef/0x320 mm/slub.c:4541 __kmalloc_reserve net/core/skbuff.c:144 [inline] __alloc_skb+0xdc/0x520 net/core/skbuff.c:212 alloc_skb include/linux/skbuff.h:1126 [inline] nlmsg_new include/net/netlink.h:953 [inline] inet_netconf_notify_devconf+0x169/0x220 net/ipv4/devinet.c:2120 __devinet_sysctl_register+0x324/0x390 net/ipv4/devinet.c:2604 devinet_sysctl_register+0x169/0x1e0 net/ipv4/devinet.c:2638 inetdev_init+0x273/0x480 net/ipv4/devinet.c:277 inetdev_event+0x1f8/0x1030 net/ipv4/devinet.c:1544 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:410 call_netdevice_notifiers_info net/core/dev.c:2054 [inline] call_netdevice_notifiers_extack net/core/dev.c:2066 [inline] call_netdevice_notifiers+0x111/0x190 net/core/dev.c:2080 register_netdevice+0x1043/0x13c0 net/core/dev.c:10087 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] free_pcp_prepare mm/page_alloc.c:1421 [inline] free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336 free_unref_page mm/page_alloc.c:3391 [inline] free_the_page mm/page_alloc.c:5429 [inline] __free_pages+0x14b/0x380 mm/page_alloc.c:5440 __vunmap+0x84d/0x9d0 mm/vmalloc.c:2307 __vfree mm/vmalloc.c:2356 [inline] vfree+0x61/0x90 mm/vmalloc.c:2387 kcov_put kernel/kcov.c:408 [inline] kcov_close+0x2b/0x50 kernel/kcov.c:510 __fput+0x2fb/0x770 fs/file_table.c:281 ____fput+0x15/0x20 fs/file_table.c:314 task_work_run+0x127/0x190 kernel/task_work.c:189 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa4f/0x2480 kernel/exit.c:872 do_group_exit+0x141/0x310 kernel/exit.c:986 get_signal+0xf7d/0x12e0 kernel/signal.c:2793 arch_do_signal_or_restart+0xbf/0x10f0 arch/x86/kernel/signal.c:805 handle_signal_work kernel/entry/common.c:145 [inline] exit_to_user_mode_loop+0xa2/0xe0 kernel/entry/common.c:169 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 Memory state around the buggy address: ffff888111a06900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888111a06980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888111a06a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888111a06a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888111a06b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================