================================================================== BUG: KASAN: use-after-free in __ipv6_get_lladdr+0x1fe/0x230 net/ipv6/addrconf.c:1852 Read of size 4 at addr ffff88807563386c by task kworker/1:9/21489 CPU: 1 PID: 21489 Comm: kworker/1:9 Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: mld mld_ifc_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x2ed mm/kasan/report.c:247 __kasan_report mm/kasan/report.c:433 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:450 __ipv6_get_lladdr+0x1fe/0x230 net/ipv6/addrconf.c:1852 mld_newpack+0x3ad/0x770 net/ipv6/mcast.c:1762 add_grhead+0x265/0x330 net/ipv6/mcast.c:1857 add_grec+0x1053/0x14e0 net/ipv6/mcast.c:1995 mld_send_cr net/ipv6/mcast.c:2082 [inline] mld_ifc_work+0x5d6/0xdc0 net/ipv6/mcast.c:2659 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 6551: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:522 kasan_kmalloc include/linux/kasan.h:269 [inline] kmem_cache_alloc_trace+0x1ea/0x4a0 mm/slab.c:3575 kmalloc include/linux/slab.h:590 [inline] kzalloc include/linux/slab.h:724 [inline] ipv6_add_addr+0x363/0x1f40 net/ipv6/addrconf.c:1092 inet6_addr_add+0x410/0xae0 net/ipv6/addrconf.c:2954 inet6_rtm_newaddr+0xf00/0x1970 net/ipv6/addrconf.c:4892 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5571 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2491 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x86d/0xda0 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 __sys_sendto+0x21c/0x320 net/socket.c:2036 __do_sys_sendto net/socket.c:2048 [inline] __se_sys_sendto net/socket.c:2044 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2044 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 7863: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xd1/0x110 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:235 [inline] __cache_free mm/slab.c:3445 [inline] kfree+0x10d/0x2c0 mm/slab.c:3803 kvfree+0x42/0x50 mm/util.c:620 kfree_rcu_work+0x5f8/0xa10 kernel/rcu/tree.c:3315 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Last potentially related work creation: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 __kasan_record_aux_stack+0xb5/0xe0 mm/kasan/generic.c:348 kvfree_call_rcu+0x74/0x990 kernel/rcu/tree.c:3550 inet6_ifa_finish_destroy+0x153/0x1b0 net/ipv6/addrconf.c:979 in6_ifa_put include/net/addrconf.h:414 [inline] addrconf_ifdown.isra.0+0x10bd/0x1630 net/ipv6/addrconf.c:3851 addrconf_notify+0xeb/0x1bb0 net/ipv6/addrconf.c:3651 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2002 call_netdevice_notifiers_extack net/core/dev.c:2014 [inline] call_netdevice_notifiers net/core/dev.c:2028 [inline] dev_close_many+0x2ff/0x620 net/core/dev.c:1603 unregister_netdevice_many+0x3ff/0x1790 net/core/dev.c:11054 default_device_exit_batch+0x2fa/0x3c0 net/core/dev.c:11607 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:171 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:593 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Second to last potentially related work creation: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 __kasan_record_aux_stack+0xb5/0xe0 mm/kasan/generic.c:348 insert_work+0x48/0x370 kernel/workqueue.c:1354 __queue_work+0x5ca/0xee0 kernel/workqueue.c:1520 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1461 [inline] __run_timers.part.0+0x49f/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 The buggy address belongs to the object at ffff888075633800 which belongs to the cache kmalloc-cg-512 of size 512 The buggy address is located 108 bytes inside of 512-byte region [ffff888075633800, ffff888075633a00) The buggy address belongs to the page: page:ffffea0001d58cc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x75633 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0001eac148 ffffea0001dd5bc8 ffff888010c43a00 raw: 0000000000000000 ffff888075633000 0000000100000004 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 0x2c20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_THISNODE), pid 7912, ts 245270210553, free_ts 245233293724 prep_new_page mm/page_alloc.c:2418 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369 __alloc_pages_node include/linux/gfp.h:570 [inline] kmem_getpages mm/slab.c:1377 [inline] cache_grow_begin+0x75/0x470 mm/slab.c:2593 cache_alloc_refill+0x27f/0x380 mm/slab.c:2965 ____cache_alloc mm/slab.c:3048 [inline] ____cache_alloc mm/slab.c:3031 [inline] slab_alloc_node mm/slab.c:3249 [inline] kmem_cache_alloc_node_trace+0x49c/0x5b0 mm/slab.c:3617 __do_kmalloc_node mm/slab.c:3639 [inline] __kmalloc_node_track_caller+0x38/0x60 mm/slab.c:3654 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0xde/0x340 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1126 [inline] alloc_skb_with_frags+0x93/0x620 net/core/skbuff.c:6078 sock_alloc_send_pskb+0x783/0x910 net/core/sock.c:2575 unix_dgram_sendmsg+0x3ec/0x1950 net/unix/af_unix.c:1811 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 sock_write_iter+0x289/0x3c0 net/socket.c:1057 call_write_iter include/linux/fs.h:2162 [inline] new_sync_write+0x429/0x660 fs/read_write.c:503 vfs_write+0x7cd/0xae0 fs/read_write.c:590 ksys_write+0x1ee/0x250 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1338 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1389 free_unref_page_prepare mm/page_alloc.c:3309 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3388 slab_destroy mm/slab.c:1627 [inline] slabs_destroy+0x89/0xc0 mm/slab.c:1647 cache_flusharray mm/slab.c:3418 [inline] ___cache_free+0x4cc/0x610 mm/slab.c:3480 qlink_free mm/kasan/quarantine.c:146 [inline] qlist_free_all+0x4e/0x110 mm/kasan/quarantine.c:165 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272 __kasan_slab_alloc+0x97/0xb0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:259 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc mm/slab.c:3323 [inline] __do_kmalloc mm/slab.c:3700 [inline] __kmalloc+0x27a/0x4d0 mm/slab.c:3711 kmalloc include/linux/slab.h:595 [inline] tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x140 security/security.c:1334 vfs_getattr fs/stat.c:157 [inline] vfs_statx+0x164/0x390 fs/stat.c:225 vfs_fstatat fs/stat.c:243 [inline] vfs_lstat include/linux/fs.h:3358 [inline] __do_sys_newlstat+0x91/0x110 fs/stat.c:398 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff888075633700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888075633780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888075633800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888075633880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888075633900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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