================================================================== BUG: KASAN: use-after-free in ext4_htree_fill_tree+0x106b/0x10d0 fs/ext4/namei.c:1246 Read of size 1 at addr ffff88812040fa67 by task syz-executor/444 CPU: 1 PID: 444 Comm: syz-executor Not tainted 5.15.185-syzkaller-1080615-g0d918fa8e88d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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: 0033:0x7fcbd47cf693 Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 82 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:00007fff62024c78 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 000055557d71e4e0 RCX: 00007fcbd47cf693 RDX: 0000000000008000 RSI: 000055557d71e4e0 RDI: 0000000000000005 RBP: 000055557d71e4b4 R08: 0000000000028b61 R09: 0000000000000000 R10: 00007fcbd4962ca0 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 000055557d71e4b0 R15: 0000000000000001 Allocated by task 361: 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_kmalloc mm/kasan/common.c:512 [inline] __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:521 kasan_kmalloc include/linux/kasan.h:227 [inline] __kmalloc_track_caller+0x13c/0x2c0 mm/slub.c:4954 kmalloc_reserve net/core/skbuff.c:357 [inline] __alloc_skb+0x21a/0x740 net/core/skbuff.c:428 alloc_skb_fclone include/linux/skbuff.h:1233 [inline] sk_stream_alloc_skb+0x21a/0xb60 net/ipv4/tcp.c:889 tcp_sendmsg_locked+0xc3e/0x3590 net/ipv4/tcp.c:1314 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1457 inet_sendmsg+0xa5/0xc0 net/ipv4/af_inet.c:830 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] sock_write_iter+0x29c/0x380 net/socket.c:1079 call_write_iter include/linux/fs.h:2212 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x802/0xf70 fs/read_write.c:594 ksys_write+0x140/0x240 fs/read_write.c:647 __do_sys_write fs/read_write.c:659 [inline] __se_sys_write fs/read_write.c:656 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:656 x64_sys_call+0x8ef/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2 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 362: 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] kfree+0xc4/0x270 mm/slub.c:4583 skb_free_head net/core/skbuff.c:656 [inline] skb_release_data+0x814/0xa10 net/core/skbuff.c:678 skb_release_all net/core/skbuff.c:743 [inline] __kfree_skb+0x50/0x70 net/core/skbuff.c:757 sk_wmem_free_skb include/net/sock.h:1652 [inline] tcp_rtx_queue_unlink_and_free+0x205/0x720 include/net/tcp.h:1908 tcp_clean_rtx_queue net/ipv4/tcp_input.c:3401 [inline] tcp_ack+0x2145/0x6000 net/ipv4/tcp_input.c:3958 tcp_rcv_established+0x100f/0x1940 net/ipv4/tcp_input.c:6019 tcp_v4_do_rcv+0x597/0x9f0 net/ipv4/tcp_ipv4.c:1725 tcp_v4_rcv+0x21cd/0x2810 net/ipv4/tcp_ipv4.c:2137 ip_protocol_deliver_rcu+0x314/0x6c0 net/ipv4/ip_input.c:204 ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] ip_local_deliver+0x2de/0x530 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:463 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:577 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:628 [inline] ip_sublist_rcv+0x747/0x850 net/ipv4/ip_input.c:636 ip_list_rcv+0x3da/0x420 net/ipv4/ip_input.c:671 __netif_receive_skb_list_ptype net/core/dev.c:5576 [inline] __netif_receive_skb_list_core+0x574/0x740 net/core/dev.c:5624 __netif_receive_skb_list net/core/dev.c:5676 [inline] netif_receive_skb_list_internal+0x7d2/0xa60 net/core/dev.c:5767 gro_normal_list net/core/dev.c:5921 [inline] napi_complete_done+0x36f/0x790 net/core/dev.c:6659 virtqueue_napi_complete drivers/net/virtio_net.c:357 [inline] virtnet_poll+0x911/0xef0 drivers/net/virtio_net.c:1592 __napi_poll+0xbe/0x590 net/core/dev.c:7083 napi_poll net/core/dev.c:7150 [inline] net_rx_action+0x371/0x8e0 net/core/dev.c:7240 handle_softirqs+0x250/0x560 kernel/softirq.c:583 __do_softirq kernel/softirq.c:621 [inline] invoke_softirq kernel/softirq.c:443 [inline] __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:670 irq_exit_rcu+0x9/0x10 kernel/softirq.c:682 common_interrupt+0xbe/0xe0 arch/x86/kernel/irq.c:242 asm_common_interrupt+0x27/0x40 arch/x86/include/asm/idtentry.h:667 The buggy address belongs to the object at ffff88812040f800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 615 bytes inside of 1024-byte region [ffff88812040f800, ffff88812040fc00) The buggy address belongs to the page: page:ffffea0004810200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x120408 head:ffffea0004810200 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 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 3, migratetype Unmovable, gfp_mask 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 361, ts 41389404556, free_ts 41389373054 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] __kmalloc_track_caller+0x169/0x2c0 mm/slub.c:4949 kmalloc_reserve net/core/skbuff.c:357 [inline] __alloc_skb+0x21a/0x740 net/core/skbuff.c:428 alloc_skb include/linux/skbuff.h:1183 [inline] __tcp_send_ack+0x9b/0x6d0 net/ipv4/tcp_output.c:3986 tcp_send_ack+0x3b/0x60 net/ipv4/tcp_output.c:4018 tcp_cleanup_rbuf+0x319/0x5f0 net/ipv4/tcp.c:1597 tcp_recvmsg_locked+0x1e03/0x2640 net/ipv4/tcp.c:2533 tcp_recvmsg+0x21b/0x720 net/ipv4/tcp.c:2563 inet_recvmsg+0x134/0x470 net/ipv4/af_inet.c:861 sock_recvmsg_nosec net/socket.c:966 [inline] sock_recvmsg net/socket.c:984 [inline] sock_read_iter+0x2a2/0x340 net/socket.c:1057 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_compound_page+0x78/0xa0 mm/page_alloc.c:828 destroy_compound_page include/linux/mm.h:989 [inline] __put_compound_page+0x77/0xb0 mm/swap.c:111 __put_page+0xbc/0xe0 mm/swap.c:127 put_page include/linux/mm.h:1295 [inline] __skb_frag_unref include/linux/skbuff.h:3252 [inline] skb_release_data+0x3d3/0xa10 net/core/skbuff.c:673 skb_release_all net/core/skbuff.c:743 [inline] __kfree_skb+0x50/0x70 net/core/skbuff.c:757 sk_eat_skb include/net/sock.h:2750 [inline] tcp_recvmsg_locked+0x14ac/0x2640 net/ipv4/tcp.c:2517 tcp_recvmsg+0x21b/0x720 net/ipv4/tcp.c:2563 inet_recvmsg+0x134/0x470 net/ipv4/af_inet.c:861 sock_recvmsg_nosec net/socket.c:966 [inline] sock_recvmsg net/socket.c:984 [inline] sock_read_iter+0x2a2/0x340 net/socket.c:1057 call_read_iter include/linux/fs.h:2206 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x68b/0xbe0 fs/read_write.c:485 ksys_read+0x140/0x240 fs/read_write.c:623 __do_sys_read fs/read_write.c:633 [inline] __se_sys_read fs/read_write.c:631 [inline] __x64_sys_read+0x7b/0x90 fs/read_write.c:631 x64_sys_call+0x96d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:1 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 Memory state around the buggy address: ffff88812040f900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88812040f980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88812040fa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88812040fa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88812040fb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================