syzbot


BUG: unable to handle kernel NULL pointer dereference in sidtab_search_core

Status: closed as dup on 2017/12/22 17:05
Reported-by: syzbot+904436b33e141b4f4c57c1ddc94199ffd2e34b9d@syzkaller.appspotmail.com
First crash: 1820d, last: 1820d
Duplicate of (1):
Title Repro Cause bisect Fix bisect Count Last Reported
KASAN: use-after-free Read in __list_del_entry_valid (2) C 11 1815d 1817d

Sample crash report:
SELinux: security_compute_sid:  unrecognized SID 1
SELinux: security_compute_sid:  unrecognized SID 1
SELinux: security_compute_sid:  unrecognized SID 1
SELinux: security_compute_sid:  unrecognized SID 1
SELinux: security_compute_sid:  unrecognized SID 1
BUG: unable to handle kernel NULL pointer dereference at 0000000000000001
IP: sidtab_search_core+0x88/0x110 security/selinux/ss/sidtab.c:100
PGD 0 P4D 0 
Oops: 0000 [#1] SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 4252 Comm: kworker/u4:1 Not tainted 4.15.0-rc3-next-20171214+ #67
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:sidtab_search_core+0x88/0x110 security/selinux/ss/sidtab.c:100
RSP: 0018:ffffc900028abc18 EFLAGS: 00010293
RAX: ffff8802131a87c0 RBX: 0000000000000001 RCX: ffffffff8165d978
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff83fd17a0
RBP: ffffc900028abc40 R08: 0000000000000001 R09: 0000000000000001
R10: ffffc900028abbe0 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000001 R14: 0000000000000000 R15: ffff880214d93800
FS:  0000000000000000(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000001 CR3: 0000000214e31000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 sidtab_search+0x1f/0x30 security/selinux/ss/sidtab.c:111
 security_compute_sid.part.11+0xe2/0x710 security/selinux/ss/services.c:1618
 security_compute_sid+0x92/0xa0 security/selinux/ss/services.c:1598
 security_transition_sid+0x57/0x70 security/selinux/ss/services.c:1764
 selinux_bprm_set_creds+0x215/0x2f0 security/selinux/hooks.c:2423
 security_bprm_set_creds+0x41/0x60 security/security.c:332
 prepare_binprm+0xae/0x1f0 fs/exec.c:1561
 do_execveat_common.isra.30+0x6f7/0xb90 fs/exec.c:1784
 do_execve+0x31/0x40 fs/exec.c:1848
 call_usermodehelper_exec_async+0x104/0x190 kernel/umh.c:100
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524
Code: 8b 5b 50 48 85 db 75 e5 e8 e6 c9 c5 ff 49 8b 5f 18 48 85 db 75 10 eb 43 e8 d6 c9 c5 ff 48 8b 5b 50 48 85 db 74 35 e8 c8 c9 c5 ff <44> 8b 23 41 83 fc 02 76 e4 e8 ba c9 c5 ff 41 83 fc 03 75 1c 48 
RIP: sidtab_search_core+0x88/0x110 security/selinux/ss/sidtab.c:100 RSP: ffffc900028abc18
CR2: 0000000000000001
---[ end trace 571c0ea6c6959387 ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-next-kasan-gce 2017/12/15 22:41 linux-next 6084b576dca2 ac20b98c .config log report syz C
* Struck through repros no longer work on HEAD.