syzbot


BUG: bad usercopy in __check_heap_object (2)

Status: closed as invalid on 2018/05/26 17:45
Subsystems: mm hardening
[Documentation on labels]
Reported-by: syzbot+73825a3f080d559e4a9a@syzkaller.appspotmail.com
First crash: 2194d, last: 2194d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: bad usercopy in __check_heap_object (3) hardening mm C 287 2042d 2113d 12/26 fixed on 2019/06/11 10:01
upstream BUG: bad usercopy in __check_heap_object hardening mm 4 2204d 2210d 0/26 closed as invalid on 2018/04/10 15:15

Sample crash report:
device lo entered promiscuous mode
usercopy: Kernel memory overwrite attempt detected to SLAB object 'names_cache' (offset 352, size 4064)!
------------[ cut here ]------------
kernel BUG at mm/usercopy.c:100!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 11981 Comm: udevd Not tainted 4.16.0+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:usercopy_abort+0xbb/0xbd mm/usercopy.c:88
RSP: 0018:ffff8801ca447a68 EFLAGS: 00010286
RAX: 0000000000000068 RBX: ffffffff887aef8c RCX: 0000000000000000
RDX: 0000000000000068 RSI: ffffffff815fa581 RDI: ffffed0039488f43
RBP: ffff8801ca447ac0 R08: ffff8801d0024780 R09: ffffed003b604f90
R10: ffffed003b604f90 R11: ffff8801db027c87 R12: ffffffff87b2fec0
R13: ffffffff87b2fe00 R14: ffffffff87b2fdc0 R15: ffffffff87b339c0
FS:  00007fb59da6e7a0(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc38c98108 CR3: 00000001adf51000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __check_heap_object+0xb5/0xb5 mm/slab.c:4443
 check_heap_object mm/usercopy.c:236 [inline]
 __check_object_size+0x4c7/0x5d9 mm/usercopy.c:259
 check_object_size include/linux/thread_info.h:112 [inline]
 strncpy_from_user+0x109/0x500 lib/strncpy_from_user.c:116
 getname_flags+0x113/0x5a0 fs/namei.c:151
 getname+0x19/0x20 fs/namei.c:211
 do_sys_open+0x39a/0x740 fs/open.c:1087
 SYSC_open fs/open.c:1111 [inline]
 SyS_open+0x2d/0x40 fs/open.c:1106
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7fb59d176120
RSP: 002b:00007ffc38ca0528 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00000000013f2870 RCX: 00007fb59d176120
RDX: 00000000000001b6 RSI: 0000000000080000 RDI: 00007ffc38ca05f0
RBP: 00007ffc38ca05a0 R08: 0000000000000008 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008
R13: 000000000041f57a R14: 00000000013e1250 R15: 000000000000000b
Code: 55 c0 e8 90 3e bc ff ff 75 c8 48 8b 55 c0 4d 89 f9 ff 75 d0 4d 89 e8 48 89 d9 4c 89 e6 41 56 48 c7 c7 60 00 b3 87 e8 80 a6 a4 ff <0f> 0b e8 65 3e bc ff e8 d0 b5 f7 ff 8b 95 14 ff ff ff 4d 89 e8 
RIP: usercopy_abort+0xbb/0xbd mm/usercopy.c:88 RSP: ffff8801ca447a68
---[ end trace 526cceb6fa94ca84 ]---

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/04/16 10:42 net-next-old 5d1365940a68 802ac912 .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.