================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xc67/0xc80 fs/ext4/xattr.c:2900 Read of size 4 at addr ffff888115838000 by task syz-executor/494 CPU: 0 PID: 494 Comm: syz-executor Not tainted 5.10.234-syzkaller-1006652-g3f5f2283d684 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118 print_address_description+0x81/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x179/0x1c0 mm/kasan/report.c:452 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_xattr_delete_inode+0xc67/0xc80 fs/ext4/xattr.c:2900 ext4_evict_inode+0x1095/0x1730 fs/ext4/inode.c:300 evict+0x526/0x9c0 fs/inode.c:612 iput_final fs/inode.c:1736 [inline] iput+0x632/0x7e0 fs/inode.c:1762 d_delete_notify include/linux/fsnotify.h:267 [inline] vfs_rmdir+0x271/0x3f0 fs/namei.c:3865 do_rmdir+0x2cf/0x5c0 fs/namei.c:3912 __do_sys_unlinkat fs/namei.c:4076 [inline] __se_sys_unlinkat fs/namei.c:4070 [inline] __x64_sys_unlinkat+0xdf/0xf0 fs/namei.c:4070 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f01a8677887 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:00007ffc4d385368 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f01a8677887 RDX: 0000000000000200 RSI: 00007ffc4d386510 RDI: 00000000ffffff9c RBP: 00007f01a86d46c6 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffc4d386510 R13: 00007f01a86d46c6 R14: 000000000000bf2b R15: 0000000000000007 Allocated by task 0: (stack is not available) Freed by task 49: 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+0x121/0x160 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+0xc0/0x190 mm/slub.c:1621 slab_free mm/slub.c:3203 [inline] kfree+0xc3/0x270 mm/slub.c:4191 skb_free_head net/core/skbuff.c:606 [inline] skb_release_data+0x5c6/0x6f0 net/core/skbuff.c:626 skb_release_all net/core/skbuff.c:680 [inline] __kfree_skb net/core/skbuff.c:694 [inline] consume_skb+0xac/0x250 net/core/skbuff.c:851 netlink_broadcast_filtered+0x114e/0x1270 net/netlink/af_netlink.c:1517 netlink_broadcast net/netlink/af_netlink.c:1539 [inline] nlmsg_multicast include/net/netlink.h:1033 [inline] nlmsg_notify+0x101/0x1c0 net/netlink/af_netlink.c:2528 rtnl_notify+0x9c/0xd0 net/core/rtnetlink.c:737 inet6_rt_notify+0x3c8/0x550 net/ipv6/route.c:6059 fib6_add_rt2node net/ipv6/ip6_fib.c:1253 [inline] fib6_add+0x233e/0x3d20 net/ipv6/ip6_fib.c:1482 __ip6_ins_rt net/ipv6/route.c:1303 [inline] ip6_route_add+0x8a/0x130 net/ipv6/route.c:3765 addrconf_prefix_route net/ipv6/addrconf.c:2461 [inline] addrconf_add_linklocal+0x5b5/0x9e0 net/ipv6/addrconf.c:3255 addrconf_addr_gen+0x572/0xd00 net/ipv6/addrconf.c:3384 addrconf_dev_config+0x342/0x5a0 net/ipv6/addrconf.c:3436 addrconf_notify+0x8c5/0xe90 net/ipv6/addrconf.c:3669 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x8c/0xf0 kernel/notifier.c:410 call_netdevice_notifiers_info net/core/dev.c:2054 [inline] netdev_state_change+0x1a3/0x250 net/core/dev.c:1484 linkwatch_do_dev+0x100/0x140 net/core/link_watch.c:167 __linkwatch_run_queue+0x4ca/0x7f0 net/core/link_watch.c:213 linkwatch_event+0x4c/0x60 net/core/link_watch.c:252 process_one_work+0x6dc/0xbd0 kernel/workqueue.c:2301 worker_thread+0xaea/0x1510 kernel/workqueue.c:2447 kthread+0x34b/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 ffff888115838000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes inside of 1024-byte region [ffff888115838000, ffff888115838400) The buggy address belongs to the page: page:ffffea0004560e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888115838800 pfn:0x115838 head:ffffea0004560e00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea0004564208 ffffea000456cc08 ffff888100042f00 raw: ffff888115838800 000000000010000f 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 95, ts 4922579615, free_ts 0 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x166/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5348 allocate_slab mm/slub.c:1808 [inline] new_slab+0x80/0x400 mm/slub.c:1869 new_slab_objects mm/slub.c:2627 [inline] ___slab_alloc+0x302/0x4b0 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] __kmalloc_track_caller+0x1f8/0x320 mm/slub.c:4536 __kmalloc_reserve net/core/skbuff.c:144 [inline] __alloc_skb+0xbc/0x510 net/core/skbuff.c:212 alloc_skb include/linux/skbuff.h:1126 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1179 [inline] netlink_sendmsg+0x7a4/0xd00 net/netlink/af_netlink.c:1876 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2376 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2430 __sys_sendmsg net/socket.c:2459 [inline] __do_sys_sendmsg net/socket.c:2468 [inline] __se_sys_sendmsg+0x1b1/0x280 net/socket.c:2466 __x64_sys_sendmsg+0x7b/0x90 net/socket.c:2466 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb page_owner free stack trace missing Memory state around the buggy address: ffff888115837f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888115837f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888115838000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888115838080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888115838100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================