================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2920 Read of size 4 at addr ffff888118188000 by task syz-executor/455 CPU: 1 PID: 455 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2920 ext4_evict_inode+0xe44/0x1450 fs/ext4/inode.c:300 evict+0x485/0x870 fs/inode.c:650 iput_final fs/inode.c:1779 [inline] iput+0x635/0x7c0 fs/inode.c:1805 d_delete_notify include/linux/fsnotify.h:278 [inline] vfs_rmdir+0x33f/0x460 fs/namei.c:4162 do_rmdir+0x259/0x6a0 fs/namei.c:4210 __do_sys_unlinkat fs/namei.c:4390 [inline] __se_sys_unlinkat fs/namei.c:4384 [inline] __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4384 x64_sys_call+0x4c0/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:264 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: 0033:0x7f6f6278ecf7 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:00007fff30b41bd8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f6f6278ecf7 RDX: 0000000000000200 RSI: 00007fff30b42d80 RDI: 00000000ffffff9c RBP: 00007f6f628021cc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007fff30b42d80 R13: 00007f6f628021cc R14: 000000000000bbd3 R15: 00007fff30b44f30 Allocated by task 324: 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:4959 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] mld_newpack+0x13a/0x9d0 net/ipv6/mcast.c:1745 add_grhead+0x5e/0x290 net/ipv6/mcast.c:1856 add_grec+0xd41/0x1100 net/ipv6/mcast.c:1994 mld_send_cr net/ipv6/mcast.c:2081 [inline] mld_ifc_work+0x1e1/0xbe0 net/ipv6/mcast.c:2658 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 324: 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] kfree+0xc4/0x270 mm/slub.c:4588 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 net/core/skbuff.c:757 [inline] kfree_skb_reason net/core/skbuff.c:778 [inline] kfree_skb+0xb9/0x2f0 net/core/skbuff.c:792 kfree_skb_list+0x41/0x70 net/core/skbuff.c:801 __dev_xmit_skb net/core/dev.c:3956 [inline] __dev_queue_xmit+0x1cc0/0x2d80 net/core/dev.c:4261 dev_queue_xmit+0x17/0x20 net/core/dev.c:4329 neigh_resolve_output+0x6cf/0x770 net/core/neighbour.c:1504 neigh_output include/net/neighbour.h:517 [inline] ip6_finish_output2+0x10b7/0x1760 net/ipv6/ip6_output.c:130 __ip6_finish_output+0x61e/0x7d0 net/ipv6/ip6_output.c:201 ip6_finish_output+0x31/0x240 net/ipv6/ip6_output.c:211 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0x1d1/0x3b0 net/ipv6/ip6_output.c:234 dst_output include/net/dst.h:453 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] mld_sendpack+0x676/0xb40 net/ipv6/mcast.c:1825 mld_send_cr net/ipv6/mcast.c:2126 [inline] mld_ifc_work+0x80c/0xbe0 net/ipv6/mcast.c:2658 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 ffff888118188000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 0 bytes inside of 2048-byte region [ffff888118188000, ffff888118188800) The buggy address belongs to the page: page:ffffea0004606200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x118188 head:ffffea0004606200 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 dead000000000122 ffff888100043200 raw: 0000000000000000 0000000000080008 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 45, ts 47360450328, free_ts 47312581250 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] __kmalloc_track_caller+0x169/0x2c0 mm/slub.c:4954 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] nlmsg_new include/net/netlink.h:953 [inline] rtmsg_ifinfo_build_skb+0x7c/0x180 net/core/rtnetlink.c:3884 unregister_netdevice_many+0x105c/0x1990 net/core/dev.c:11154 default_device_exit_batch+0x330/0x390 net/core/dev.c:11683 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x602/0xad0 net/core/net_namespace.c:599 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 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+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 mm/slub.c:2046 [inline] __unfreeze_partials+0x160/0x190 mm/slub.c:2532 put_cpu_partial+0xc6/0x120 mm/slub.c:2612 __slab_free+0x1d4/0x290 mm/slub.c:3395 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_trace+0xfb/0x270 mm/slub.c:3272 kmalloc include/linux/slab.h:616 [inline] kzalloc include/linux/slab.h:747 [inline] mld_add_delrec net/ipv6/mcast.c:742 [inline] igmp6_leave_group net/ipv6/mcast.c:2632 [inline] igmp6_group_dropped+0x445/0x9f0 net/ipv6/mcast.c:722 __ipv6_dev_mc_dec+0x224/0x460 net/ipv6/mcast.c:977 Memory state around the buggy address: ffff888118187f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888118187f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888118188000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888118188080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888118188100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================