netlink: 12 bytes leftover after parsing attributes in process `syz-executor3'. tc_dump_action: action bad kind netlink: 12 bytes leftover after parsing attributes in process `syz-executor3'. tc_dump_action: action bad kind ================================================================== BUG: KASAN: use-after-free in kernel_accept+0x2a4/0x310 net/socket.c:3254 Read of size 8 at addr ffff8801cc08a128 by task kworker/1:0/19 CPU: 1 PID: 19 Comm: kworker/1:0 Not tainted 4.18.0-rc7+ #38 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events smc_tcp_listen_work 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+0x242/0x2fe mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 kernel_accept+0x2a4/0x310 net/socket.c:3254 smc_clcsock_accept net/smc/af_smc.c:701 [inline] smc_tcp_listen_work+0x222/0xef0 net/smc/af_smc.c:1114 process_one_work+0xc73/0x1ba0 kernel/workqueue.c:2153 worker_thread+0x189/0x13c0 kernel/workqueue.c:2296 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Allocated by task 15203: 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/0x760 mm/slab.c:3554 sock_alloc_inode+0x78/0x320 net/socket.c:244 alloc_inode+0x63/0x190 fs/inode.c:210 new_inode_pseudo+0x71/0x1a0 fs/inode.c:895 sock_alloc+0x41/0x270 net/socket.c:568 __sock_create+0x175/0x940 net/socket.c:1251 sock_create_kern+0x3b/0x50 net/socket.c:1333 smc_create+0x141/0x360 net/smc/af_smc.c:1714 __sock_create+0x53c/0x940 net/socket.c:1287 sock_create net/socket.c:1327 [inline] __sys_socket+0x106/0x260 net/socket.c:1357 __do_sys_socket net/socket.c:1366 [inline] __se_sys_socket net/socket.c:1364 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1364 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 15203: 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+0x86/0x2d0 mm/slab.c:3756 sock_destroy_inode+0x56/0x70 net/socket.c:274 destroy_inode+0x159/0x200 fs/inode.c:267 evict+0x5d5/0x990 fs/inode.c:575 iput_final fs/inode.c:1506 [inline] iput+0x635/0xaa0 fs/inode.c:1532 __sock_release+0x1f1/0x260 net/socket.c:611 sock_release+0x17/0x20 net/socket.c:619 smc_release+0x1a8/0x720 net/smc/af_smc.c:146 __sock_release+0xd7/0x260 net/socket.c:600 sock_close+0x19/0x20 net/socket.c:1151 __fput+0x355/0x8b0 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x1ec/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:192 [inline] exit_to_usermode_loop+0x313/0x370 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 ffff8801cc08a100 which belongs to the cache sock_inode_cache of size 992 The buggy address is located 40 bytes inside of 992-byte region [ffff8801cc08a100, ffff8801cc08a4e0) The buggy address belongs to the page: page:ffffea0007302280 count:1 mapcount:0 mapping:ffff8801d9fe73c0 index:0xffff8801cc08affd flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea0007244dc8 ffffea000724d808 ffff8801d9fe73c0 raw: ffff8801cc08affd ffff8801cc08a100 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801cc08a000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801cc08a080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801cc08a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801cc08a180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801cc08a200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================