================================================================== BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:199 [inline] BUG: KASAN: use-after-free in sock_cgroup_ptr include/linux/cgroup.h:836 [inline] BUG: KASAN: use-after-free in inet_diag_bc_sk+0xb64/0xc70 net/ipv4/inet_diag.c:749 Read of size 8 at addr ffff8880a6667200 by task syz-executor.4/11199 CPU: 0 PID: 11199 Comm: syz-executor.4 Not tainted 5.7.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:382 __kasan_report.cold+0x35/0x4d mm/kasan/report.c:511 kasan_report+0x33/0x50 mm/kasan/common.c:625 __read_once_size include/linux/compiler.h:199 [inline] sock_cgroup_ptr include/linux/cgroup.h:836 [inline] inet_diag_bc_sk+0xb64/0xc70 net/ipv4/inet_diag.c:749 inet_diag_dump_icsk+0xbe4/0x1306 net/ipv4/inet_diag.c:1061 __inet_diag_dump+0x8d/0x240 net/ipv4/inet_diag.c:1113 netlink_dump+0x50b/0xf50 net/netlink/af_netlink.c:2245 __netlink_dump_start+0x63f/0x910 net/netlink/af_netlink.c:2353 netlink_dump_start include/linux/netlink.h:246 [inline] inet_diag_handler_cmd+0x263/0x2c0 net/ipv4/inet_diag.c:1278 __sock_diag_cmd net/core/sock_diag.c:233 [inline] sock_diag_rcv_msg+0x2fe/0x3e0 net/core/sock_diag.c:264 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2469 sock_diag_rcv+0x26/0x40 net/core/sock_diag.c:275 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 sock_write_iter+0x289/0x3c0 net/socket.c:1004 call_write_iter include/linux/fs.h:1907 [inline] do_iter_readv_writev+0x5a8/0x850 fs/read_write.c:694 do_iter_write fs/read_write.c:999 [inline] do_iter_write+0x18b/0x600 fs/read_write.c:980 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1072 do_writev+0x27f/0x300 fs/read_write.c:1115 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0002a6ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 000000000050d140 RCX: 000000000045c829 RDX: 0000000000000004 RSI: 0000000020000200 RDI: 0000000000000004 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000d18 R14: 00000000004cb1f4 R15: 00007f0002a6f6d4 Allocated by task 10487: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468 slab_post_alloc_hook mm/slab.h:586 [inline] slab_alloc_node mm/slab.c:3263 [inline] kmem_cache_alloc_node+0x13c/0x760 mm/slab.c:3575 __alloc_skb+0xba/0x5a0 net/core/skbuff.c:198 alloc_skb include/linux/skbuff.h:1083 [inline] nlmsg_new include/net/netlink.h:940 [inline] mpls_netconf_notify_devconf+0x4a/0x110 net/mpls/af_mpls.c:1187 mpls_dev_sysctl_register+0x1fe/0x2d0 net/mpls/af_mpls.c:1425 mpls_add_dev net/mpls/af_mpls.c:1472 [inline] mpls_dev_notify+0x275/0x880 net/mpls/af_mpls.c:1598 notifier_call_chain+0xc0/0x230 kernel/notifier.c:83 call_netdevice_notifiers_info net/core/dev.c:1948 [inline] call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1933 call_netdevice_notifiers_extack net/core/dev.c:1960 [inline] call_netdevice_notifiers net/core/dev.c:1974 [inline] register_netdevice+0xd70/0x10b0 net/core/dev.c:9435 register_netdev+0x2d/0x50 net/core/dev.c:9528 loopback_net_init+0x73/0x160 drivers/net/loopback.c:216 ops_init+0xaf/0x420 net/core/net_namespace.c:151 setup_net+0x2de/0x860 net/core/net_namespace.c:341 copy_net_ns+0x293/0x590 net/core/net_namespace.c:482 create_new_namespaces+0x3fb/0xb30 kernel/nsproxy.c:108 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:229 ksys_unshare+0x43d/0x8e0 kernel/fork.c:2969 __do_sys_unshare kernel/fork.c:3037 [inline] __se_sys_unshare kernel/fork.c:3035 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3035 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 10487: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] kasan_set_free_info mm/kasan/common.c:317 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456 __cache_free mm/slab.c:3426 [inline] kmem_cache_free+0x7f/0x320 mm/slab.c:3694 kfree_skbmem net/core/skbuff.c:622 [inline] kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:616 __kfree_skb net/core/skbuff.c:679 [inline] consume_skb net/core/skbuff.c:837 [inline] consume_skb+0xfb/0x400 net/core/skbuff.c:831 netlink_broadcast_filtered+0x34f/0xd40 net/netlink/af_netlink.c:1513 netlink_broadcast net/netlink/af_netlink.c:1535 [inline] nlmsg_multicast include/net/netlink.h:1020 [inline] nlmsg_notify+0x90/0x250 net/netlink/af_netlink.c:2512 mpls_netconf_notify_devconf+0xa9/0x110 net/mpls/af_mpls.c:1199 mpls_dev_sysctl_register+0x1fe/0x2d0 net/mpls/af_mpls.c:1425 mpls_add_dev net/mpls/af_mpls.c:1472 [inline] mpls_dev_notify+0x275/0x880 net/mpls/af_mpls.c:1598 notifier_call_chain+0xc0/0x230 kernel/notifier.c:83 call_netdevice_notifiers_info net/core/dev.c:1948 [inline] call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1933 call_netdevice_notifiers_extack net/core/dev.c:1960 [inline] call_netdevice_notifiers net/core/dev.c:1974 [inline] register_netdevice+0xd70/0x10b0 net/core/dev.c:9435 register_netdev+0x2d/0x50 net/core/dev.c:9528 loopback_net_init+0x73/0x160 drivers/net/loopback.c:216 ops_init+0xaf/0x420 net/core/net_namespace.c:151 setup_net+0x2de/0x860 net/core/net_namespace.c:341 copy_net_ns+0x293/0x590 net/core/net_namespace.c:482 create_new_namespaces+0x3fb/0xb30 kernel/nsproxy.c:108 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:229 ksys_unshare+0x43d/0x8e0 kernel/fork.c:2969 __do_sys_unshare kernel/fork.c:3037 [inline] __se_sys_unshare kernel/fork.c:3035 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3035 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 The buggy address belongs to the object at ffff8880a6667200 which belongs to the cache skbuff_head_cache of size 224 The buggy address is located 0 bytes inside of 224-byte region [ffff8880a6667200, ffff8880a66672e0) The buggy address belongs to the page: page:ffffea00029999c0 refcount:1 mapcount:0 mapping:000000004db3cdd8 index:0xffff8880a6667c00 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00029096c8 ffffea000243de08 ffff8880a900ea80 raw: ffff8880a6667c00 ffff8880a66670c0 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a6667100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a6667180: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a6667200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a6667280: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880a6667300: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ==================================================================