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BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xbe3/0xbf0 fs/ext4/xattr.c:2909
Read of size 4 at addr ffff8881247d9000 by task syz-executor/459

CPU: 1 PID: 459 Comm: syz-executor Not tainted 5.10.240-syzkaller-1008073-gad9a98ef27a4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 ext4_xattr_delete_inode+0xbe3/0xbf0 fs/ext4/xattr.c:2909
 ext4_evict_inode+0x106f/0x16e0 fs/ext4/inode.c:300
 evict+0x478/0x910 fs/inode.c:612
 iput_final fs/inode.c:1736 [inline]
 iput+0x638/0x7c0 fs/inode.c:1762
 d_delete_notify include/linux/fsnotify.h:267 [inline]
 vfs_rmdir+0x2bd/0x3e0 fs/namei.c:3865
 do_rmdir+0x218/0x620 fs/namei.c:3912
 __do_sys_unlinkat fs/namei.c:4076 [inline]
 __se_sys_unlinkat fs/namei.c:4070 [inline]
 __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4070
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f7aeacc3167
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 07 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd384d23a8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f7aeacc3167
RDX: 0000000000000200 RSI: 00007ffd384d3550 RDI: 00000000ffffff9c
RBP: 00007f7aead3164a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffd384d3550
R13: 00007f7aead3164a R14: 000000000000c12f R15: 00007ffd384d5730

Allocated by task 471:
 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:430 [inline]
 __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:463
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:583
 slab_alloc_node mm/slub.c:2947 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x165/0x2e0 mm/slub.c:2960
 dst_alloc+0x176/0x4f0 net/core/dst.c:93
 ip6_dst_alloc net/ipv6/route.c:340 [inline]
 icmp6_dst_alloc+0xf5/0x560 net/ipv6/route.c:3169
 ndisc_send_skb+0x267/0xb40 net/ipv6/ndisc.c:493
 ndisc_send_rs+0x6e5/0x960 net/ipv6/ndisc.c:707
 addrconf_dad_completed+0x97f/0xe80 net/ipv6/addrconf.c:4283
 addrconf_dad_work+0xc18/0x1410 net/ipv6/addrconf.c:-1
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13b0 kernel/workqueue.c:2447
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Freed by task 0:
 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]
 kmem_cache_free+0x100/0x2d0 mm/slub.c:3219
 dst_destroy+0x18a/0x240 net/core/dst.c:126
 dst_destroy_rcu+0x19/0x20 net/core/dst.c:139
 rcu_do_batch+0x4df/0xa80 kernel/rcu/tree.c:2494
 rcu_core+0x55f/0xd60 kernel/rcu/tree.c:2735
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748
 __do_softirq+0x255/0x563 kernel/softirq.c:309

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 __call_rcu kernel/rcu/tree.c:2980 [inline]
 call_rcu+0x10e/0x1050 kernel/rcu/tree.c:3054
 dst_release+0x123/0x190 net/core/dst.c:183
 refdst_drop include/net/dst.h:253 [inline]
 skb_dst_drop include/net/dst.h:265 [inline]
 __dev_queue_xmit+0x8d2/0x2540 net/core/dev.c:4166
 dev_queue_xmit+0x17/0x20 net/core/dev.c:4243
 neigh_resolve_output+0x6cf/0x770 net/core/neighbour.c:1509
 neigh_output include/net/neighbour.h:517 [inline]
 ip6_finish_output2+0xecd/0x1500 net/ipv6/ip6_output.c:130
 __ip6_finish_output+0x5ff/0x790 net/ipv6/ip6_output.c:201
 ip6_finish_output+0x33/0x1f0 net/ipv6/ip6_output.c:211
 NF_HOOK_COND include/linux/netfilter.h:288 [inline]
 ip6_output+0x1d1/0x3b0 net/ipv6/ip6_output.c:234
 dst_output include/net/dst.h:451 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ndisc_send_skb+0x6f5/0xb40 net/ipv6/ndisc.c:513
 ndisc_send_rs+0x6e5/0x960 net/ipv6/ndisc.c:707
 addrconf_dad_completed+0x97f/0xe80 net/ipv6/addrconf.c:4283
 addrconf_dad_work+0xc18/0x1410 net/ipv6/addrconf.c:-1
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13b0 kernel/workqueue.c:2447
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

The buggy address belongs to the object at ffff8881247d9000
 which belongs to the cache ip6_dst_cache of size 240
The buggy address is located 0 bytes inside of
 240-byte region [ffff8881247d9000, ffff8881247d90f0)
The buggy address belongs to the page:
page:ffffea000491f640 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1247d9
flags: 0x4000000000000200(slab)
raw: 4000000000000200 dead000000000100 dead000000000122 ffff888101db6000
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 471, ts 49491492498, free_ts 49481460582
 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]
 kmem_cache_alloc+0x1af/0x2e0 mm/slub.c:2960
 dst_alloc+0x176/0x4f0 net/core/dst.c:93
 ip6_dst_alloc net/ipv6/route.c:340 [inline]
 icmp6_dst_alloc+0xf5/0x560 net/ipv6/route.c:3169
 mld_sendpack+0x4b0/0xa80 net/ipv6/mcast.c:1665
 mld_send_initial_cr+0x246/0x2b0 net/ipv6/mcast.c:2093
 ipv6_mc_dad_complete+0x76/0x3c0 net/ipv6/mcast.c:2100
 addrconf_dad_completed+0x773/0xe80 net/ipv6/addrconf.c:4263
 addrconf_dad_work+0xc18/0x1410 net/ipv6/addrconf.c:-1
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13b0 kernel/workqueue.c:2447
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 free_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336
 free_unref_page mm/page_alloc.c:3391 [inline]
 free_the_page mm/page_alloc.c:5416 [inline]
 __free_pages+0x14b/0x380 mm/page_alloc.c:5427
 free_pages+0x82/0x90 mm/page_alloc.c:5438
 tlb_batch_list_free mm/mmu_gather.c:61 [inline]
 tlb_finish_mmu+0x248/0x300 mm/mmu_gather.c:329
 unmap_region+0x32c/0x380 mm/mmap.c:2807
 __do_munmap+0x63c/0x850 mm/mmap.c:3037
 __vm_munmap mm/mmap.c:3090 [inline]
 __do_sys_munmap mm/mmap.c:3116 [inline]
 __se_sys_munmap+0x127/0x1b0 mm/mmap.c:3112
 __x64_sys_munmap+0x5b/0x70 mm/mmap.c:3112
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Memory state around the buggy address:
 ffff8881247d8f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881247d8f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8881247d9000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8881247d9080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff8881247d9100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
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