================================================================== BUG: KASAN: use-after-free in tomoyo_get_socket_name security/tomoyo/realpath.c:238 [inline] BUG: KASAN: use-after-free in tomoyo_realpath_from_path+0x719/0x7b0 security/tomoyo/realpath.c:284 Read of size 4 at addr ffff8880981a4460 by task syz-executor.3/15411 CPU: 1 PID: 15411 Comm: syz-executor.3 Not tainted 5.3.0-rc6-next-20190830 #75 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:634 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131 tomoyo_get_socket_name security/tomoyo/realpath.c:238 [inline] tomoyo_realpath_from_path+0x719/0x7b0 security/tomoyo/realpath.c:284 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x2a8/0x3f0 security/tomoyo/file.c:771 tomoyo_file_open security/tomoyo/tomoyo.c:319 [inline] tomoyo_file_open+0xa9/0xd0 security/tomoyo/tomoyo.c:314 security_file_open+0x71/0x300 security/security.c:1497 do_dentry_open+0x373/0x1250 fs/open.c:784 vfs_open+0xa0/0xd0 fs/open.c:914 do_last fs/namei.c:3416 [inline] path_openat+0x10e9/0x46d0 fs/namei.c:3533 do_filp_open+0x1a1/0x280 fs/namei.c:3563 do_sys_open+0x3fe/0x5d0 fs/open.c:1097 __do_sys_open fs/open.c:1115 [inline] __se_sys_open fs/open.c:1110 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1110 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4137d1 Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 19 00 00 c3 48 83 ec 08 e8 0a fa ff ff 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007f7fa8f14bb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00000000004137d1 RDX: fffffffffffffffa RSI: 0000000000000000 RDI: 00007f7fa8f14bd0 RBP: 000000000075bf20 R08: 0000000000000000 R09: 000000000000000f R10: 0000000000000004 R11: 0000000000000293 R12: 00007f7fa8f156d4 R13: 00000000004c8ef7 R14: 00000000004dff48 R15: 00000000ffffffff Allocated by task 15462: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:510 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:483 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:518 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc mm/slab.c:3319 [inline] kmem_cache_alloc+0x121/0x710 mm/slab.c:3483 sk_prot_alloc+0x67/0x310 net/core/sock.c:1597 sk_alloc+0x39/0xf70 net/core/sock.c:1657 unix_create1+0xc2/0x530 net/unix/af_unix.c:761 unix_create+0x103/0x1e0 net/unix/af_unix.c:822 __sock_create+0x3d8/0x730 net/socket.c:1418 sock_create net/socket.c:1469 [inline] __sys_socketpair+0x1ea/0x5d0 net/socket.c:1569 __do_sys_socketpair net/socket.c:1622 [inline] __se_sys_socketpair net/socket.c:1619 [inline] __x64_sys_socketpair+0x97/0xf0 net/socket.c:1619 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 15408: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] kasan_set_free_info mm/kasan/common.c:332 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:471 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480 __cache_free mm/slab.c:3425 [inline] kmem_cache_free+0x86/0x320 mm/slab.c:3693 sk_prot_free net/core/sock.c:1638 [inline] __sk_destruct+0x4bc/0x6e0 net/core/sock.c:1726 sk_destruct+0x86/0xa0 net/core/sock.c:1734 __sk_free+0xfb/0x360 net/core/sock.c:1745 sk_free+0x42/0x50 net/core/sock.c:1756 sock_put include/net/sock.h:1725 [inline] unix_release_sock+0x66c/0xbd0 net/unix/af_unix.c:553 unix_release+0x44/0x90 net/unix/af_unix.c:832 __sock_release+0xce/0x280 net/socket.c:590 sock_close+0x1e/0x30 net/socket.c:1268 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x65f/0x760 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880981a4100 which belongs to the cache UNIX(65:syz3) of size 1728 The buggy address is located 864 bytes inside of 1728-byte region [ffff8880981a4100, ffff8880981a47c0) The buggy address belongs to the page: page:ffffea0002606900 refcount:1 mapcount:0 mapping:ffff8880a79d3a80 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea00026c9dc8 ffffea00027c1248 ffff8880a79d3a80 raw: 0000000000000000 ffff8880981a4100 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880981a4300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880981a4380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880981a4400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880981a4480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880981a4500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================