================================================================== BUG: KASAN: slab-out-of-bounds in ext4_htree_fill_tree+0x1066/0x10d0 fs/ext4/namei.c:1221 Read of size 1 at addr ffff888118c64a67 by task syz-executor/476 CPU: 1 PID: 476 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025 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: 0033:0x7f0f1222abf3 Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 f2 44 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:00007ffc52a514e8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 000055557d7574e0 RCX: 00007f0f1222abf3 RDX: 0000000000008000 RSI: 000055557d7574e0 RDI: 0000000000000005 RBP: 000055557d7574b4 R08: 0000000000028b61 R09: 0000000000000000 R10: 00007f0f12357ca0 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 000055557d7574b0 R15: 000000000000b78f Allocated by task 0: (stack is not available) Freed by task 386: 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:1595 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1621 slab_free mm/slub.c:3203 [inline] kfree+0xc0/0x270 mm/slub.c:4191 skb_free_head net/core/skbuff.c:606 [inline] skb_release_data+0x532/0x670 net/core/skbuff.c:626 skb_release_all net/core/skbuff.c:680 [inline] __kfree_skb net/core/skbuff.c:694 [inline] kfree_skb+0xb9/0x2f0 net/core/skbuff.c:713 ip6_mc_input+0x235/0x2a0 net/ipv6/ip6_input.c:574 dst_input include/net/dst.h:461 [inline] ip6_rcv_finish+0x18c/0x360 net/ipv6/ip6_input.c:80 NF_HOOK include/linux/netfilter.h:299 [inline] ipv6_rcv+0xec/0x210 net/ipv6/ip6_input.c:301 __netif_receive_skb_one_core net/core/dev.c:5402 [inline] __netif_receive_skb+0xc8/0x280 net/core/dev.c:5516 process_backlog+0x368/0x600 net/core/dev.c:6423 napi_poll net/core/dev.c:6874 [inline] net_rx_action+0x432/0xdd0 net/core/dev.c:6944 __do_softirq+0x255/0x563 kernel/softirq.c:309 The buggy address belongs to the object at ffff888118c64800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 103 bytes to the right of 512-byte region [ffff888118c64800, ffff888118c64a00) The buggy address belongs to the page: page:ffffea0004631900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x118c64 head:ffffea0004631900 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea000463a400 0000000200000002 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 96, ts 4580851660, free_ts 0 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:5357 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1808 [inline] new_slab+0x84/0x3f0 mm/slub.c:1869 new_slab_objects mm/slub.c:2627 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2791 __slab_alloc+0x63/0xa0 mm/slub.c:2831 slab_alloc_node mm/slub.c:2913 [inline] slab_alloc mm/slub.c:2955 [inline] __kmalloc_track_caller+0x1ef/0x320 mm/slub.c:4536 __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] alloc_skb_with_frags+0xa2/0x560 net/core/skbuff.c:5993 sock_alloc_send_pskb+0x853/0x980 net/core/sock.c:2388 unix_dgram_sendmsg+0x5f4/0x17d0 net/unix/af_unix.c:1725 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] sock_write_iter+0x29c/0x380 net/socket.c:1018 call_write_iter include/linux/fs.h:2066 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0x725/0xd60 fs/read_write.c:605 ksys_write+0x140/0x240 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write fs/read_write.c:667 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:667 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 page_owner free stack trace missing Memory state around the buggy address: ffff888118c64900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888118c64980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888118c64a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888118c64a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888118c64b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================