================================================================== BUG: KASAN: use-after-free in ext4_htree_fill_tree+0x106b/0x10d0 fs/ext4/namei.c:1246 Read of size 1 at addr ffff88810d928d1b by task syz-executor/465 CPU: 1 PID: 465 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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: 0033:0x7f0487f40693 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:00007ffc8e95e108 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00005555900694e0 RCX: 00007f0487f40693 RDX: 0000000000008000 RSI: 00005555900694e0 RDI: 0000000000000005 RBP: 00005555900694b4 R08: 0000000000028b61 R09: 0000000000000000 R10: 00007f04880d3ca0 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 00005555900694b0 R15: 0000000000000001 Allocated by task 45: 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_slab_alloc+0xbd/0xf0 mm/kasan/common.c:466 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550 slab_alloc_node mm/slub.c:3245 [inline] slab_alloc mm/slub.c:3255 [inline] kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260 kmem_cache_alloc_node include/linux/slab.h:489 [inline] __alloc_skb+0xe0/0x740 net/core/skbuff.c:416 alloc_skb include/linux/skbuff.h:1183 [inline] nlmsg_new include/net/netlink.h:953 [inline] inet6_rt_notify+0x287/0x470 net/ipv6/route.c:6173 fib6_add_rt2node net/ipv6/ip6_fib.c:1255 [inline] fib6_add+0x2279/0x3d10 net/ipv6/ip6_fib.c:1484 __ip6_ins_rt net/ipv6/route.c:1308 [inline] ip6_route_add+0x89/0x130 net/ipv6/route.c:3884 addrconf_add_mroute net/ipv6/addrconf.c:2532 [inline] addrconf_add_dev+0x329/0x430 net/ipv6/addrconf.c:2550 addrconf_dev_config net/ipv6/addrconf.c:3429 [inline] addrconf_init_auto_addrs+0x765/0xb90 net/ipv6/addrconf.c:3517 addrconf_notify+0x95d/0xde0 net/ipv6/addrconf.c:3686 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:391 call_netdevice_notifiers_info net/core/dev.c:2057 [inline] netdev_state_change+0x16a/0x210 net/core/dev.c:1448 linkwatch_do_dev+0x115/0x160 net/core/link_watch.c:167 __linkwatch_run_queue+0x4a9/0x7b0 net/core/link_watch.c:213 linkwatch_event+0x4c/0x60 net/core/link_watch.c:252 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Freed by task 45: 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:1728 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754 slab_free mm/slub.c:3526 [inline] kmem_cache_free+0x100/0x320 mm/slub.c:3544 kfree_skbmem+0x10c/0x180 net/core/skbuff.c:-1 __kfree_skb net/core/skbuff.c:758 [inline] consume_skb+0xb3/0x1f0 net/core/skbuff.c:930 netlink_broadcast_filtered+0x113a/0x1230 net/netlink/af_netlink.c:1538 netlink_broadcast net/netlink/af_netlink.c:1560 [inline] nlmsg_multicast include/net/netlink.h:1033 [inline] nlmsg_notify+0xed/0x1b0 net/netlink/af_netlink.c:2554 rtnl_notify+0x9a/0xc0 net/core/rtnetlink.c:759 inet6_rt_notify+0x365/0x470 net/ipv6/route.c:6185 fib6_add_rt2node net/ipv6/ip6_fib.c:1255 [inline] fib6_add+0x2279/0x3d10 net/ipv6/ip6_fib.c:1484 __ip6_ins_rt net/ipv6/route.c:1308 [inline] ip6_route_add+0x89/0x130 net/ipv6/route.c:3884 addrconf_add_mroute net/ipv6/addrconf.c:2532 [inline] addrconf_add_dev+0x329/0x430 net/ipv6/addrconf.c:2550 addrconf_dev_config net/ipv6/addrconf.c:3429 [inline] addrconf_init_auto_addrs+0x765/0xb90 net/ipv6/addrconf.c:3517 addrconf_notify+0x95d/0xde0 net/ipv6/addrconf.c:3686 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:391 call_netdevice_notifiers_info net/core/dev.c:2057 [inline] netdev_state_change+0x16a/0x210 net/core/dev.c:1448 linkwatch_do_dev+0x115/0x160 net/core/link_watch.c:167 __linkwatch_run_queue+0x4a9/0x7b0 net/core/link_watch.c:213 linkwatch_event+0x4c/0x60 net/core/link_watch.c:252 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff88810d928c80 which belongs to the cache skbuff_head_cache of size 248 The buggy address is located 155 bytes inside of 248-byte region [ffff88810d928c80, ffff88810d928d78) The buggy address belongs to the page: page:ffffea0004364a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10d928 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff8881081aa000 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 325, ts 24257593627, free_ts 24156238135 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:5808 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1937 [inline] new_slab+0xa1/0x4d0 mm/slub.c:2000 ___slab_alloc+0x381/0x810 mm/slub.c:3033 __slab_alloc+0x49/0x90 mm/slub.c:3120 slab_alloc_node mm/slub.c:3211 [inline] slab_alloc mm/slub.c:3255 [inline] kmem_cache_alloc+0x138/0x260 mm/slub.c:3260 kmem_cache_alloc_node include/linux/slab.h:489 [inline] __alloc_skb+0xe0/0x740 net/core/skbuff.c:416 alloc_skb include/linux/skbuff.h:1183 [inline] nlmsg_new include/net/netlink.h:953 [inline] netlink_ack+0x3a6/0xb60 net/netlink/af_netlink.c:2446 netlink_rcv_skb+0x265/0x430 net/netlink/af_netlink.c:2517 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5668 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x86a/0xb70 net/netlink/af_netlink.c:1922 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] __sys_sendto+0x423/0x580 net/socket.c:2063 __do_sys_sendto net/socket.c:2075 [inline] __se_sys_sendto net/socket.c:2071 [inline] __x64_sys_sendto+0xe5/0x100 net/socket.c:2071 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_pages+0x6c/0x100 mm/page_alloc.c:5884 __free_slab+0xe8/0x1e0 mm/slub.c:2025 free_slab mm/slub.c:2040 [inline] discard_slab+0x29/0x40 mm/slub.c:2046 __slab_free+0x211/0x290 mm/slub.c:3431 do_slab_free mm/slub.c:3514 [inline] ___cache_free+0x104/0x120 mm/slub.c:3535 qlink_free+0x4d/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xf0 mm/kasan/common.c:443 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550 slab_alloc_node mm/slub.c:3245 [inline] slab_alloc mm/slub.c:3255 [inline] kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260 getname_flags+0xb9/0x500 fs/namei.c:138 user_path_at_empty+0x30/0x1c0 fs/namei.c:2882 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0xfb/0xa60 fs/stat.c:221 Memory state around the buggy address: ffff88810d928c00: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc ffff88810d928c80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88810d928d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc ^ ffff88810d928d80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff88810d928e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== EXT4-fs error (device loop1): __ext4_get_inode_loc:4352: comm syz-executor: Invalid inode table block 14875662660405297151 in block_group 0 EXT4-fs error (device loop1) in ext4_reserve_inode_write:5867: Corrupt filesystem EXT4-fs error (device loop1): ext4_dirty_inode:6071: inode #2: comm syz-executor: mark_inode_dirty error