================================================================== BUG: KASAN: slab-out-of-bounds in vsscanf+0x2666/0x2ef0 lib/vsprintf.c:3321 Read of size 1 at addr ffff88808a148983 by task syz-executor.4/13009 CPU: 1 PID: 13009 Comm: syz-executor.4 Not tainted 5.7.0-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+0x1e9/0x30e lib/dump_stack.c:118 print_address_description+0x66/0x5a0 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report+0x132/0x1d0 mm/kasan/report.c:530 vsscanf+0x2666/0x2ef0 lib/vsprintf.c:3321 sscanf+0x6c/0x90 lib/vsprintf.c:3527 smk_set_cipso+0x374/0x6c0 security/smack/smackfs.c:908 __vfs_write+0x9c/0x6e0 fs/read_write.c:495 vfs_write+0x274/0x580 fs/read_write.c:559 ksys_write+0x11b/0x220 fs/read_write.c:612 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca69 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:00007f34f25d6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000050dbc0 RCX: 000000000045ca69 RDX: 0000000000000082 RSI: 0000000020001180 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000d27 R14: 00000000004cf810 R15: 00007f34f25d76d4 Allocated by task 13009: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x103/0x140 mm/kasan/common.c:494 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc_track_caller+0x249/0x320 mm/slab.c:3671 memdup_user_nul+0x26/0xf0 mm/util.c:259 smk_set_cipso+0xff/0x6c0 security/smack/smackfs.c:859 __vfs_write+0x9c/0x6e0 fs/read_write.c:495 vfs_write+0x274/0x580 fs/read_write.c:559 ksys_write+0x11b/0x220 fs/read_write.c:612 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 3874: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x220 mm/slab.c:3757 security_cred_free+0xbf/0x100 security/security.c:1604 put_cred_rcu+0xca/0x350 kernel/cred.c:114 do_faccessat+0x3cc/0x870 fs/open.c:464 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 The buggy address belongs to the object at ffff88808a148900 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 131 bytes inside of 192-byte region [ffff88808a148900, ffff88808a1489c0) The buggy address belongs to the page: page:ffffea0002285200 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88808a148500 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00027a5e48 ffffea000287edc8 ffff8880aa400000 raw: ffff88808a148500 ffff88808a148000 000000010000000b 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808a148880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88808a148900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88808a148980: 03 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88808a148a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808a148a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================