================================================================== BUG: KASAN: use-after-free in ext4_htree_fill_tree+0x1066/0x10d0 fs/ext4/namei.c:1246 Read of size 1 at addr ffff88811cc79535 by task syz-executor/463 CPU: 0 PID: 463 Comm: syz-executor Not tainted 6.1.145-syzkaller-1169987-gc750dc582629 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x71/0x210 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:427 kasan_report+0x122/0x150 mm/kasan/report.c:531 __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: 0033:0x7fdd77bbfad3 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:00007ffd672918c8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 000055558b7584e0 RCX: 00007fdd77bbfad3 RDX: 0000000000008000 RSI: 000055558b7584e0 RDI: 0000000000000005 RBP: 000055558b7584b4 R08: 0000000000028b61 R09: 0000000000000000 R10: 00007fdd77d7cca0 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 000055558b7584b0 R15: 00007ffd67293b80 Allocated by task 463: 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:3421 [inline] kmem_cache_alloc_node+0x181/0x340 mm/slub.c:3468 __alloc_skb+0xea/0x4b0 net/core/skbuff.c:508 alloc_skb include/linux/skbuff.h:1290 [inline] alloc_uevent_skb+0x85/0x240 lib/kobject_uevent.c:290 uevent_net_broadcast_tagged lib/kobject_uevent.c:351 [inline] kobject_uevent_net_broadcast+0x1b4/0x5b0 lib/kobject_uevent.c:412 kobject_uevent_env+0x54f/0x730 lib/kobject_uevent.c:608 kobject_uevent+0x1d/0x30 lib/kobject_uevent.c:657 __kobject_del+0xd7/0x2f0 lib/kobject.c:593 kobject_cleanup lib/kobject.c:672 [inline] kobject_release lib/kobject.c:712 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1ee/0x280 lib/kobject.c:729 netdev_queue_update_kobjects+0x3db/0x470 net/core/net-sysfs.c:1727 netif_set_real_num_tx_queues+0x17f/0x7f0 net/core/dev.c:2959 veth_init_queues drivers/net/veth.c:1670 [inline] veth_newlink+0x874/0xbe0 drivers/net/veth.c:1787 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:2503 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6171 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x8b1/0xa30 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x8aa/0xbc0 net/netlink/af_netlink.c:1860 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 463: 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:1745 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1771 slab_free mm/slub.c:3686 [inline] kmem_cache_free+0x12d/0x300 mm/slub.c:3711 kfree_skbmem+0x10c/0x180 net/core/skbuff.c:-1 __kfree_skb net/core/skbuff.c:874 [inline] consume_skb+0xb3/0x1f0 net/core/skbuff.c:1038 netlink_broadcast+0x10a2/0x11a0 net/netlink/af_netlink.c:1509 uevent_net_broadcast_tagged lib/kobject_uevent.c:372 [inline] kobject_uevent_net_broadcast+0x511/0x5b0 lib/kobject_uevent.c:412 kobject_uevent_env+0x54f/0x730 lib/kobject_uevent.c:608 kobject_uevent+0x1d/0x30 lib/kobject_uevent.c:657 __kobject_del+0xd7/0x2f0 lib/kobject.c:593 kobject_cleanup lib/kobject.c:672 [inline] kobject_release lib/kobject.c:712 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1ee/0x280 lib/kobject.c:729 netdev_queue_update_kobjects+0x3db/0x470 net/core/net-sysfs.c:1727 netif_set_real_num_tx_queues+0x17f/0x7f0 net/core/dev.c:2959 veth_init_queues drivers/net/veth.c:1670 [inline] veth_newlink+0x874/0xbe0 drivers/net/veth.c:1787 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:2503 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6171 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x8b1/0xa30 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x8aa/0xbc0 net/netlink/af_netlink.c:1860 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 The buggy address belongs to the object at ffff88811cc79500 which belongs to the cache skbuff_head_cache of size 256 The buggy address is located 53 bytes inside of 256-byte region [ffff88811cc79500, ffff88811cc79600) The buggy address belongs to the physical page: page:ffffea0004731e40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11cc79 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea0004731d00 dead000000000002 ffff888100ba5080 raw: 0000000000000000 00000000000c000c 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 109, tgid 109 (udevd), ts 6899797086, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2637 prep_new_page+0x1c/0x110 mm/page_alloc.c:2644 get_page_from_freelist+0x2c7b/0x2cf0 mm/page_alloc.c:4544 __alloc_pages+0x1c3/0x450 mm/page_alloc.c:5858 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1962 [inline] new_slab+0x98/0x3d0 mm/slub.c:2015 ___slab_alloc+0x6f6/0xb50 mm/slub.c:3203 __slab_alloc+0x5e/0xa0 mm/slub.c:3302 slab_alloc_node mm/slub.c:3387 [inline] kmem_cache_alloc_node+0x1c2/0x340 mm/slub.c:3468 __alloc_skb+0xea/0x4b0 net/core/skbuff.c:508 alloc_skb include/linux/skbuff.h:1290 [inline] alloc_skb_with_frags+0xa8/0x620 net/core/skbuff.c:6165 sock_alloc_send_pskb+0x853/0x980 net/core/sock.c:2756 unix_dgram_sendmsg+0x592/0x16d0 net/unix/af_unix.c:1947 sock_sendmsg_nosec net/socket.c:716 [inline] __sock_sendmsg net/socket.c:728 [inline] sock_write_iter+0x2ca/0x3b0 net/socket.c:1133 call_write_iter include/linux/fs.h:2282 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x5db/0xca0 fs/read_write.c:584 ksys_write+0x140/0x240 fs/read_write.c:637 page_owner free stack trace missing Memory state around the buggy address: ffff88811cc79400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811cc79480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff88811cc79500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811cc79580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811cc79600: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ================================================================== EXT4-fs (loop2): unmounting filesystem.