================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2920 Read of size 4 at addr ffff88807a8f6000 by task syz-executor/4770 CPU: 1 PID: 4770 Comm: syz-executor Not tainted 5.15.183-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2920 ext4_evict_inode+0xc47/0x1080 fs/ext4/inode.c:299 evict+0x485/0x870 fs/inode.c:647 d_delete_notify include/linux/fsnotify.h:267 [inline] vfs_rmdir+0x3b4/0x430 fs/namei.c:4162 do_rmdir+0x295/0x710 fs/namei.c:4210 __do_sys_unlinkat fs/namei.c:4390 [inline] __se_sys_unlinkat fs/namei.c:4384 [inline] __x64_sys_unlinkat+0xc0/0xe0 fs/namei.c:4384 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: 0033:0x7fc0faadb6c7 Code: 73 01 c3 48 c7 c1 b0 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc01334ca8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007fc0faadb6c7 RDX: 0000000000000200 RSI: 00007ffc01335e50 RDI: 00000000ffffff9c RBP: 00007fc0fab27336 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffc01335e50 R13: 00007fc0fab27336 R14: 0000000000019cac R15: 0000000000000007 Allocated by task 4279: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3233 dst_alloc+0x101/0x160 net/core/dst.c:88 ip6_dst_alloc net/ipv6/route.c:342 [inline] icmp6_dst_alloc+0x78/0x4a0 net/ipv6/route.c:3268 ndisc_send_skb+0x3e2/0x14a0 net/ipv6/ndisc.c:493 ndisc_send_ns+0x63c/0x840 net/ipv6/ndisc.c:655 addrconf_dad_work+0xa47/0x1520 net/ipv6/addrconf.c:4204 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Freed by task 4997: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3515 dst_destroy+0x20e/0x2e0 net/core/dst.c:120 rcu_do_batch kernel/rcu/tree.c:2523 [inline] rcu_core+0x962/0x15d0 kernel/rcu/tree.c:2763 handle_softirqs+0x328/0x820 kernel/softirq.c:558 __do_softirq kernel/softirq.c:592 [inline] invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:641 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 Last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:3007 [inline] call_rcu+0x179/0x920 kernel/rcu/tree.c:3087 refdst_drop include/net/dst.h:255 [inline] skb_dst_drop include/net/dst.h:267 [inline] __dev_queue_xmit+0x884/0x2ed0 net/core/dev.c:4244 neigh_output include/net/neighbour.h:509 [inline] ip6_finish_output2+0x1070/0x1500 net/ipv6/ip6_output.c:130 dst_output include/net/dst.h:452 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ndisc_send_skb+0xbea/0x14a0 net/ipv6/ndisc.c:513 ndisc_send_ns+0x63c/0x840 net/ipv6/ndisc.c:655 addrconf_dad_work+0xa47/0x1520 net/ipv6/addrconf.c:4204 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff88807a8f6000 which belongs to the cache ip6_dst_cache of size 232 The buggy address is located 0 bytes inside of 232-byte region [ffff88807a8f6000, ffff88807a8f60e8) The buggy address belongs to the page: page:ffffea0001ea3d80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7a8f6 memcg:ffff888020d84d01 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 0000000000000000 dead000000000122 ffff888021a02dc0 raw: 0000000000000000 00000000000c000c 00000001ffffffff ffff888020d84d01 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 4279, ts 105721171723, free_ts 99116224673 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5466 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1975 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x195/0x290 mm/slub.c:3233 dst_alloc+0x101/0x160 net/core/dst.c:88 ip6_dst_alloc net/ipv6/route.c:342 [inline] icmp6_dst_alloc+0x78/0x4a0 net/ipv6/route.c:3268 ndisc_send_skb+0x3e2/0x14a0 net/ipv6/ndisc.c:493 ndisc_send_ns+0x63c/0x840 net/ipv6/ndisc.c:655 addrconf_dad_work+0xa47/0x1520 net/ipv6/addrconf.c:4204 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x94/0x280 mm/page_alloc.c:3396 __vunmap+0x8ab/0xa40 mm/vmalloc.c:2621 kcov_put kernel/kcov.c:417 [inline] kcov_close+0x27/0x50 kernel/kcov.c:519 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x616/0x20a0 kernel/exit.c:874 do_group_exit+0x12e/0x300 kernel/exit.c:996 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff88807a8f5f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807a8f5f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88807a8f6000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807a8f6080: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff88807a8f6100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb 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