================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xc9a/0xca0 fs/ext4/xattr.c:2897 Read of size 4 at addr ffff888121780000 by task syz-executor/462 CPU: 0 PID: 462 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x71/0x200 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:420 kasan_report+0x122/0x150 mm/kasan/report.c:524 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:350 ext4_xattr_delete_inode+0xc9a/0xca0 fs/ext4/xattr.c:2897 ext4_evict_inode+0xe48/0x1450 fs/ext4/inode.c:298 evict+0x4c4/0x8c0 fs/inode.c:709 iput_final fs/inode.c:1845 [inline] iput+0x633/0x690 fs/inode.c:1871 d_delete_notify include/linux/fsnotify.h:292 [inline] vfs_rmdir+0x3ad/0x4f0 fs/namei.c:4211 do_rmdir+0x261/0x6b0 fs/namei.c:4259 __do_sys_unlinkat fs/namei.c:4439 [inline] __se_sys_unlinkat fs/namei.c:4433 [inline] __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4433 x64_sys_call+0x79f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:264 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb2b4183bc7 Code: 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 b8 07 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc1189eb78 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007fb2b4183bc7 RDX: 0000000000000200 RSI: 00007ffc1189fd20 RDI: 00000000ffffff9c RBP: 00007fb2b4201fd2 R08: 0000000000018670 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffc1189fd20 R13: 00007fb2b4201fd2 R14: 000000000000a66a R15: 00007ffc118a1ed0 Allocated by task 292: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:380 [inline] __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389 kasan_kmalloc include/linux/kasan.h:212 [inline] __do_kmalloc_node mm/slab_common.c:938 [inline] __kmalloc_node_track_caller+0xb1/0x1e0 mm/slab_common.c:958 kmalloc_reserve net/core/skbuff.c:449 [inline] __alloc_skb+0x226/0x4a0 net/core/skbuff.c:518 alloc_skb include/linux/skbuff.h:1322 [inline] nlmsg_new include/net/netlink.h:987 [inline] inet_netconf_notify_devconf+0x169/0x220 net/ipv4/devinet.c:2128 __devinet_sysctl_unregister net/ipv4/devinet.c:2639 [inline] devinet_sysctl_unregister net/ipv4/devinet.c:2663 [inline] inetdev_destroy net/ipv4/devinet.c:329 [inline] inetdev_event+0x80a/0x10a0 net/ipv4/devinet.c:1615 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xa1/0x110 kernel/notifier.c:455 call_netdevice_notifiers_info net/core/dev.c:2022 [inline] call_netdevice_notifiers_extack net/core/dev.c:2060 [inline] call_netdevice_notifiers net/core/dev.c:2074 [inline] unregister_netdevice_many+0x104a/0x1910 net/core/dev.c:11006 default_device_exit_batch+0x951/0x9f0 net/core/dev.c:11519 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x630/0xb10 net/core/net_namespace.c:604 process_one_work+0x717/0xc30 kernel/workqueue.c:2302 worker_thread+0xa4d/0x11d0 kernel/workqueue.c:2449 kthread+0x281/0x320 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Freed by task 292: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:242 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:250 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1750 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776 slab_free mm/slub.c:3712 [inline] __kmem_cache_free+0xb7/0x1b0 mm/slub.c:3728 kfree+0x6f/0xf0 mm/slab_common.c:990 skb_free_head net/core/skbuff.c:765 [inline] skb_release_data+0x63d/0x8a0 net/core/skbuff.c:794 skb_release_all net/core/skbuff.c:859 [inline] __kfree_skb net/core/skbuff.c:873 [inline] consume_skb+0xab/0x1f0 net/core/skbuff.c:1038 netlink_broadcast+0x10c4/0x11c0 net/netlink/af_netlink.c:1527 nlmsg_multicast include/net/netlink.h:1067 [inline] nlmsg_notify+0xdf/0x1a0 net/netlink/af_netlink.c:2569 rtnl_notify+0x9a/0xc0 net/core/rtnetlink.c:799 inet_netconf_notify_devconf+0x1c2/0x220 net/ipv4/devinet.c:2140 __devinet_sysctl_unregister net/ipv4/devinet.c:2639 [inline] devinet_sysctl_unregister net/ipv4/devinet.c:2663 [inline] inetdev_destroy net/ipv4/devinet.c:329 [inline] inetdev_event+0x80a/0x10a0 net/ipv4/devinet.c:1615 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xa1/0x110 kernel/notifier.c:455 call_netdevice_notifiers_info net/core/dev.c:2022 [inline] call_netdevice_notifiers_extack net/core/dev.c:2060 [inline] call_netdevice_notifiers net/core/dev.c:2074 [inline] unregister_netdevice_many+0x104a/0x1910 net/core/dev.c:11006 default_device_exit_batch+0x951/0x9f0 net/core/dev.c:11519 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x630/0xb10 net/core/net_namespace.c:604 process_one_work+0x717/0xc30 kernel/workqueue.c:2302 worker_thread+0xa4d/0x11d0 kernel/workqueue.c:2449 kthread+0x281/0x320 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff888121780000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 0 bytes inside of 512-byte region [ffff888121780000, ffff888121780200) The buggy address belongs to the physical page: page:ffffea000485e000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x121780 head:ffffea000485e000 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 dead000000000122 ffff888100042f00 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 327, tgid 327 (kworker/1:2), ts 29407749774, free_ts 29038254575 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2673 prep_new_page+0x1c/0x110 mm/page_alloc.c:2680 get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4587 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5931 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1967 [inline] new_slab+0x98/0x3e0 mm/slub.c:2020 ___slab_alloc+0x70f/0xb70 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] __kmem_cache_alloc_node+0x204/0x2d0 mm/slub.c:3423 __do_kmalloc_node mm/slab_common.c:937 [inline] __kmalloc_node_track_caller+0xa1/0x1e0 mm/slab_common.c:958 kmalloc_reserve net/core/skbuff.c:449 [inline] __alloc_skb+0x226/0x4a0 net/core/skbuff.c:518 alloc_skb include/linux/skbuff.h:1322 [inline] nlmsg_new include/net/netlink.h:987 [inline] br_mdb_notify+0x2d4/0x9a0 net/bridge/br_mdb.c:568 __br_multicast_add_group+0x5e6/0x960 net/bridge/br_multicast.c:1392 br_multicast_add_group net/bridge/br_multicast.c:1414 [inline] br_ip6_multicast_add_group net/bridge/br_multicast.c:1466 [inline] br_ip6_multicast_mld2_report net/bridge/br_multicast.c:2863 [inline] br_multicast_ipv6_rcv net/bridge/br_multicast.c:3801 [inline] br_multicast_rcv+0x402d/0x76c0 net/bridge/br_multicast.c:3859 br_handle_frame_finish+0x57f/0x1420 net/bridge/br_input.c:136 nf_hook_bridge_pre net/bridge/br_input.c:282 [inline] br_handle_frame+0x6c6/0x10d0 net/bridge/br_input.c:406 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1581 [inline] free_pcp_prepare mm/page_alloc.c:1655 [inline] free_unref_page_prepare+0x81b/0x820 mm/page_alloc.c:3622 free_unref_page+0x93/0x530 mm/page_alloc.c:3720 free_the_page mm/page_alloc.c:863 [inline] __free_pages+0x67/0x100 mm/page_alloc.c:6021 __vunmap+0xa3c/0xc00 mm/vmalloc.c:2739 __vfree mm/vmalloc.c:2788 [inline] vfree+0x61/0x90 mm/vmalloc.c:2819 kcov_put kernel/kcov.c:437 [inline] kcov_close+0x2b/0x50 kernel/kcov.c:533 __fput+0x1fd/0x8f0 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x1e1/0x250 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0xb0d/0x29f0 kernel/exit.c:896 do_group_exit+0x21b/0x2e0 kernel/exit.c:1040 get_signal+0x167c/0x1700 kernel/signal.c:2904 arch_do_signal_or_restart+0xd1/0x11c0 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x7a/0xb0 kernel/entry/common.c:174 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303 Memory state around the buggy address: ffff88812177ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88812177ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888121780000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888121780080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888121780100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem.