================================================================== BUG: KASAN: use-after-free in ext4_htree_fill_tree+0x131b/0x13e0 fs/ext4/namei.c:1246 Read of size 1 at addr ffff88811bd05a67 by task syz-executor/482 CPU: 1 PID: 482 Comm: syz-executor Not tainted 5.15.180-syzkaller-1080019-g8034ec1338e8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1c0 lib/dump_stack.c:106 print_address_description+0x87/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0x179/0x1c0 mm/kasan/report.c:444 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306 ext4_htree_fill_tree+0x131b/0x13e0 fs/ext4/namei.c:1246 ext4_dx_readdir fs/ext4/dir.c:609 [inline] ext4_readdir+0x2f75/0x3960 fs/ext4/dir.c:145 iterate_dir+0x265/0x600 fs/readdir.c:-1 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0x1c1/0x460 fs/readdir.c:354 __x64_sys_getdents64+0x7b/0x90 fs/readdir.c:354 x64_sys_call+0x5ae/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:218 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fb172e21693 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:00007ffd06861b18 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 000055557ca3d4e0 RCX: 00007fb172e21693 RDX: 0000000000008000 RSI: 000055557ca3d4e0 RDI: 0000000000000005 RBP: 000055557ca3d4b4 R08: 0000000000028b61 R09: 0000000000000000 R10: 00007fb172fb4ca0 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 000055557ca3d4b0 R15: 0000000000000001 Allocated by task 39: 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+0xb1/0xe0 mm/kasan/common.c:466 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:550 slab_alloc_node mm/slub.c:3240 [inline] slab_alloc mm/slub.c:3250 [inline] kmem_cache_alloc+0xf5/0x250 mm/slub.c:3255 dst_alloc+0x164/0x1e0 net/core/dst.c:92 ip6_dst_alloc net/ipv6/route.c:342 [inline] icmp6_dst_alloc+0xfc/0x560 net/ipv6/route.c:3280 ndisc_send_skb+0x26f/0xc40 net/ipv6/ndisc.c:493 ndisc_send_ns+0x7ee/0xa70 net/ipv6/ndisc.c:655 addrconf_dad_work+0xb29/0x1710 net/ipv6/addrconf.c:4221 process_one_work+0x6bb/0xc10 kernel/workqueue.c:2325 worker_thread+0xad5/0x12a0 kernel/workqueue.c:2472 kthread+0x421/0x510 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Freed by task 26: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x126/0x160 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+0xbd/0x190 mm/slub.c:1749 slab_free mm/slub.c:3521 [inline] kmem_cache_free+0x115/0x330 mm/slub.c:3539 dst_destroy+0x1a2/0x280 net/core/dst.c:124 dst_destroy_rcu+0x19/0x20 net/core/dst.c:137 rcu_do_batch+0x57a/0xc10 kernel/rcu/tree.c:2523 rcu_core+0x517/0x1020 kernel/rcu/tree.c:2763 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776 handle_softirqs+0x25e/0x5c0 kernel/softirq.c:565 __do_softirq+0xb/0xd kernel/softirq.c:603 Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd3/0xf0 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 __call_rcu_common kernel/rcu/tree.c:3007 [inline] call_rcu+0x123/0x10b0 kernel/rcu/tree.c:3125 call_rcu_hurry include/linux/rcupdate.h:89 [inline] dst_release+0x11b/0x180 net/core/dst.c:181 refdst_drop include/net/dst.h:255 [inline] skb_dst_drop include/net/dst.h:267 [inline] __dev_queue_xmit+0x88f/0x2e80 net/core/dev.c:4251 dev_queue_xmit+0x17/0x20 net/core/dev.c:4328 neigh_resolve_output+0x6b8/0x760 net/core/neighbour.c:1504 neigh_output include/net/neighbour.h:517 [inline] ip6_finish_output2+0xf95/0x16f0 net/ipv6/ip6_output.c:130 __ip6_finish_output+0x60f/0x7c0 net/ipv6/ip6_output.c:201 ip6_finish_output+0x31/0x210 net/ipv6/ip6_output.c:211 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0x1f7/0x4c0 net/ipv6/ip6_output.c:234 dst_output include/net/dst.h:453 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] ndisc_send_skb+0x72a/0xc40 net/ipv6/ndisc.c:513 ndisc_send_ns+0x7ee/0xa70 net/ipv6/ndisc.c:655 addrconf_dad_work+0xb29/0x1710 net/ipv6/addrconf.c:4221 process_one_work+0x6bb/0xc10 kernel/workqueue.c:2325 worker_thread+0xad5/0x12a0 kernel/workqueue.c:2472 kthread+0x421/0x510 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff88811bd05a00 which belongs to the cache ip6_dst_cache of size 240 The buggy address is located 103 bytes inside of 240-byte region [ffff88811bd05a00, ffff88811bd05af0) The buggy address belongs to the page: page:ffffea00046f4140 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11bd05 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff888107fb4c00 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 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 39, ts 55588150430, free_ts 55560283957 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1a3/0x1b0 mm/page_alloc.c:2605 prep_new_page+0x1b/0x110 mm/page_alloc.c:2611 get_page_from_freelist+0x3550/0x35d0 mm/page_alloc.c:4485 __alloc_pages+0x27e/0x8f0 mm/page_alloc.c:5781 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1932 [inline] new_slab+0x9a/0x4e0 mm/slub.c:1995 ___slab_alloc+0x39e/0x830 mm/slub.c:3028 __slab_alloc+0x4a/0x90 mm/slub.c:3115 slab_alloc_node mm/slub.c:3206 [inline] slab_alloc mm/slub.c:3250 [inline] kmem_cache_alloc+0x139/0x250 mm/slub.c:3255 dst_alloc+0x164/0x1e0 net/core/dst.c:92 ip6_dst_alloc net/ipv6/route.c:342 [inline] icmp6_dst_alloc+0xfc/0x560 net/ipv6/route.c:3280 ndisc_send_skb+0x26f/0xc40 net/ipv6/ndisc.c:493 ndisc_send_ns+0x7ee/0xa70 net/ipv6/ndisc.c:655 addrconf_dad_work+0xb29/0x1710 net/ipv6/addrconf.c:4221 process_one_work+0x6bb/0xc10 kernel/workqueue.c:2325 worker_thread+0xad5/0x12a0 kernel/workqueue.c:2472 kthread+0x421/0x510 kernel/kthread.c:337 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+0x7c8/0x7d0 mm/page_alloc.c:3534 free_unref_page+0xe8/0x750 mm/page_alloc.c:3616 free_the_page mm/page_alloc.c:805 [inline] __free_pages+0x61/0xf0 mm/page_alloc.c:5857 __free_slab+0xec/0x1d0 mm/slub.c:2020 free_slab mm/slub.c:2035 [inline] discard_slab mm/slub.c:2041 [inline] __unfreeze_partials+0x165/0x1a0 mm/slub.c:2527 put_cpu_partial+0xc4/0x120 mm/slub.c:2607 __slab_free+0x1c8/0x290 mm/slub.c:3390 do_slab_free mm/slub.c:3509 [inline] ___cache_free+0x109/0x120 mm/slub.c:3530 qlink_free+0x4d/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x44/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x15a/0x180 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:443 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:550 slab_alloc_node mm/slub.c:3240 [inline] slab_alloc mm/slub.c:3250 [inline] kmem_cache_alloc+0xf5/0x250 mm/slub.c:3255 kmem_cache_alloc_node include/linux/slab.h:489 [inline] __alloc_skb+0xbe/0x550 net/core/skbuff.c:416 alloc_skb include/linux/skbuff.h:1183 [inline] mld_newpack+0x146/0x9b0 net/ipv6/mcast.c:1746 Memory state around the buggy address: ffff88811bd05900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811bd05980: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc >ffff88811bd05a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811bd05a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ffff88811bd05b00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ==================================================================