KASAN: invalid-free in tomoyo_realpath_from

Title	Replies (including bot)	Last reply
Reminder: 2 open syzbot bugs in "security/tomoyo" subsystem	1 (1)	2019/07/24 02:42
Reminder: 2 open syzbot bugs in "security/tomoyo" subsystem	1 (1)	2019/07/02 05:14
KASAN: invalid-free in tomoyo_realpath_from_path	1 (2)	2019/05/28 07:38

================================================================== BUG: KASAN: double-free or invalid-free in tomoyo_realpath_from_path+0x1de/0x7a0 security/tomoyo/realpath.c:319 CPU: 1 PID: 11697 Comm: syz-executor.3 Not tainted 5.2.0-rc1+ #2 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.cold+0x7c/0x20d mm/kasan/report.c:188 kasan_report_invalid_free+0x65/0xa0 mm/kasan/report.c:279 __kasan_slab_free+0x13a/0x150 mm/kasan/common.c:430 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3432 [inline] kfree+0xcf/0x220 mm/slab.c:3755 tomoyo_realpath_from_path+0x1de/0x7a0 security/tomoyo/realpath.c:319 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:1458 do_dentry_open+0x373/0x1250 fs/open.c:765 vfs_open+0xa0/0xd0 fs/open.c:887 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:1070 __do_sys_open fs/open.c:1088 [inline] __se_sys_open fs/open.c:1083 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1083 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4571f0 Code: 31 c0 e9 45 ff ff ff 0f 1f 00 80 3f 00 0f 84 f7 00 00 00 55 53 b9 02 00 00 00 be 00 08 09 00 89 c8 48 81 ec 98 00 00 00 0f 05 <48> 3d 00 f0 ff ff 48 89 c3 0f 87 e9 00 00 00 85 db 0f 88 2f 01 00 RSP: 002b:00007ffee56b06a0 EFLAGS: 00000206 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00000000000cb440 RCX: 00000000004571f0 RDX: 000000000000000c RSI: 0000000000090800 RDI: 00007ffee56b1880 RBP: 0000000000000002 R08: 0000000000000001 R09: 0000555557133940 R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffee56b1880 R13: 00007ffee56b1870 R14: 0000000000000000 R15: 00007ffee56b1880 Allocated by task 11696: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:503 __do_kmalloc mm/slab.c:3660 [inline] __kmalloc+0x15c/0x740 mm/slab.c:3669 kmalloc include/linux/slab.h:552 [inline] tomoyo_realpath_from_path+0xcd/0x7a0 security/tomoyo/realpath.c:277 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:1458 do_dentry_open+0x373/0x1250 fs/open.c:765 vfs_open+0xa0/0xd0 fs/open.c:887 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:1070 __do_sys_open fs/open.c:1088 [inline] __se_sys_open fs/open.c:1083 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1083 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 11696: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3432 [inline] kfree+0xcf/0x220 mm/slab.c:3755 tomoyo_realpath_from_path+0x1de/0x7a0 security/tomoyo/realpath.c:319 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:1458 do_dentry_open+0x373/0x1250 fs/open.c:765 vfs_open+0xa0/0xd0 fs/open.c:887 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:1070 __do_sys_open fs/open.c:1088 [inline] __se_sys_open fs/open.c:1083 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1083 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88808b756780 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1792 bytes inside of 4096-byte region [ffff88808b756780, ffff88808b757780) The buggy address belongs to the page: page:ffffea00022dd580 refcount:1 mapcount:0 mapping:ffff8880aa400dc0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0002924e08 ffffea00027a6588 ffff8880aa400dc0 raw: 0000000000000000 ffff88808b756780 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808b756d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808b756e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808b756e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff88808b756f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88808b756f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================