================================================================== BUG: KASAN: use-after-free in sock_i_ino+0x94/0xa0 net/core/sock.c:1921 Read of size 8 at addr ffff8801b77d60f0 by task syz-executor4/26682 CPU: 0 PID: 26682 Comm: syz-executor4 Not tainted 4.19.0-rc2-next-20180904+ #55 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+0x1c9/0x2b4 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 sock_i_ino+0x94/0xa0 net/core/sock.c:1921 tipc_sk_fill_sock_diag+0x3be/0xdb0 net/tipc/socket.c:3316 __tipc_add_sock_diag+0x22f/0x360 net/tipc/diag.c:62 tipc_nl_sk_walk+0x122/0x1d0 net/tipc/socket.c:3250 tipc_diag_dump+0x24/0x30 net/tipc/diag.c:73 netlink_dump+0x519/0xd50 net/netlink/af_netlink.c:2233 __netlink_dump_start+0x4f1/0x6f0 net/netlink/af_netlink.c:2329 netlink_dump_start include/linux/netlink.h:213 [inline] tipc_sock_diag_handler_dump+0x28e/0x3d0 net/tipc/diag.c:91 __sock_diag_cmd net/core/sock_diag.c:232 [inline] sock_diag_rcv_msg+0x31d/0x410 net/core/sock_diag.c:263 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2454 sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:274 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x5a0/0x760 net/netlink/af_netlink.c:1343 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:632 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2115 __sys_sendmsg+0x11d/0x290 net/socket.c:2153 __do_sys_sendmsg net/socket.c:2162 [inline] __se_sys_sendmsg net/socket.c:2160 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4572d9 Code: fd b4 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 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd3f4504c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fd3f45056d4 RCX: 00000000004572d9 RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000006 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d4e80 R14: 00000000004c93c9 R15: 0000000000000000 Allocated by task 26682: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x710 mm/slab.c:3554 sock_alloc_inode+0x1d/0x260 net/socket.c:244 alloc_inode+0x63/0x190 fs/inode.c:210 new_inode_pseudo+0x71/0x1a0 fs/inode.c:903 sock_alloc+0x41/0x270 net/socket.c:548 __sock_create+0x175/0x940 net/socket.c:1240 sock_create net/socket.c:1316 [inline] __sys_socket+0x106/0x260 net/socket.c:1346 __do_sys_socket net/socket.c:1355 [inline] __se_sys_socket net/socket.c:1353 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1353 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 26678: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x280 mm/slab.c:3756 sock_destroy_inode+0x51/0x60 net/socket.c:272 destroy_inode+0x159/0x200 fs/inode.c:267 evict+0x5d5/0x990 fs/inode.c:575 iput_final fs/inode.c:1547 [inline] iput+0x5fa/0xa00 fs/inode.c:1573 dentry_unlink_inode+0x461/0x5e0 fs/dcache.c:374 __dentry_kill+0x44c/0x7a0 fs/dcache.c:566 dentry_kill+0xc9/0x5a0 fs/dcache.c:685 dput.part.26+0x66b/0x7a0 fs/dcache.c:846 dput+0x15/0x20 fs/dcache.c:828 __fput+0x505/0xa80 fs/file_table.c:294 ____fput+0x15/0x20 fs/file_table.c:312 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801b77d6080 which belongs to the cache sock_inode_cache(49:syz4) of size 984 The buggy address is located 112 bytes inside of 984-byte region [ffff8801b77d6080, ffff8801b77d6458) The buggy address belongs to the page: page:ffffea0006ddf580 count:1 mapcount:0 mapping:ffff8801d8406080 index:0xffff8801b77d6ffd flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea0006180308 ffffea0007324948 ffff8801d8406080 raw: ffff8801b77d6ffd ffff8801b77d6080 0000000100000003 ffff88018be76580 page dumped because: kasan: bad access detected page->mem_cgroup:ffff88018be76580 Memory state around the buggy address: ffff8801b77d5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801b77d6000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801b77d6080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801b77d6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b77d6180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================