vm: fix crash message extraction regexp

First, "cut here" is not interesting as it always follows
by a more descriptive message.
Unreferenced object is interesting.
Also, strip \r at the end.
Add a test.

2 files changed, 101 insertions, 1 deletions

diff --git a/vm/vm.go b/vm/vm.go
index 49ce4ac87..ea2e367c7 100644
--- a/vm/vm.go
+++ b/vm/vm.go
@@ -56,6 +56,6 @@ func Create(typ string, cfg *Config) (Instance, error) {
 }
 
 var (
-	CrashRe    = regexp.MustCompile("\\[ cut here \\]|Kernel panic.*|BUG:.*|WARNING:.*|INFO:.*|unable to handle|general protection fault|UBSAN:.*")
+	CrashRe    = regexp.MustCompile("Kernel panic[^\r\n]*|BUG:[^\r\n]*|kernel BUG[^\r\n]*|WARNING:[^\r\n]*|INFO:[^\r\n]*|unable to handle|general protection fault|UBSAN:[^\r\n]*|unreferenced object[^\r\n]*")
 	TimeoutErr = errors.New("timeout")
 )
diff --git a/vm/vm_test.go b/vm/vm_test.go
new file mode 100644
index 000000000..896db8e57
--- /dev/null
+++ b/vm/vm_test.go
@@ -0,0 +1,100 @@
+// Copyright 2015 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package vm
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestCrashRe(t *testing.T) {
+	tests := map[string]string{
+		`
+[   50.583499] something 
+[   50.583499] BUG: unable to handle kernel paging request at 00000000ffffff8a
+[   50.583499] IP: [<     inline     >] list_del include/linux/list.h:107 
+`: "BUG: unable to handle kernel paging request at 00000000ffffff8a",
+		`
+[   50.583499] something
+[   50.583499] INFO: rcu_sched self-detected stall on CPU
+[   50.583499]         0: (20822 ticks this GP) idle=94b/140000000000001/0
+`: "INFO: rcu_sched self-detected stall on CPU",
+		`
+[   50.583499] general protection fault: 0000 [#1] SMP KASAN
+[   50.583499] Modules linked in: 
+`: "general protection fault",
+		`
+[   50.583499] BUG: unable to handle kernel NULL pointer dereference at 000000000000003a
+[   50.583499] Modules linked in: 
+`: "BUG: unable to handle kernel NULL pointer dereference at 000000000000003a",
+		`
+[   50.583499] WARNING: CPU: 2 PID: 2636 at ipc/shm.c:162 shm_open+0x74/0x80()
+[   50.583499] Modules linked in: 
+`: "WARNING: CPU: 2 PID: 2636 at ipc/shm.c:162 shm_open+0x74/0x80()",
+		`
+[   50.583499] BUG: KASAN: use after free in remove_wait_queue+0xfb/0x120 at addr ffff88002db3cf50
+[   50.583499] Write of size 8 by task syzkaller_execu/10568 
+`: "BUG: KASAN: use after free in remove_wait_queue+0xfb/0x120 at addr ffff88002db3cf50",
+		`
+BUG UNIX (Not tainted): kasan: bad access detected
+`: "",
+		`
+[   50.583499] [ INFO: possible circular locking dependency detected ]
+[   50.583499] 4.3.0+ #30 Not tainted
+`: "INFO: possible circular locking dependency detected ]",
+		`
+BUG: unable to handle kernel paging request at 00000000ffffff8a
+IP: [<ffffffff810a376f>] __call_rcu.constprop.76+0x1f/0x280 kernel/rcu/tree.c:3046
+`: "BUG: unable to handle kernel paging request at 00000000ffffff8a",
+		`
+==================================================================
+BUG: KASAN: slab-out-of-bounds in memcpy+0x1d/0x40 at addr ffff88003a6bd110
+Read of size 8 by task a.out/6260
+`: "BUG: KASAN: slab-out-of-bounds in memcpy+0x1d/0x40 at addr ffff88003a6bd110",
+		`
+[   50.583499] unreferenced object 0xffff880039a55260 (size 64):
+[   50.583499]   comm "executor", pid 11746, jiffies 4298984475 (age 16.078s)
+`: "unreferenced object 0xffff880039a55260 (size 64):",
+		`
+[   50.583499] UBSAN: Undefined behaviour in kernel/time/hrtimer.c:310:16
+[   50.583499] signed integer overflow:
+`: "UBSAN: Undefined behaviour in kernel/time/hrtimer.c:310:16",
+		`
+------------[ cut here ]------------
+kernel BUG at fs/buffer.c:1917!
+invalid opcode: 0000 [#1] SMP
+`: "kernel BUG at fs/buffer.c:1917!",
+		`
+BUG: sleeping function called from invalid context at include/linux/wait.h:1095 
+in_atomic(): 1, irqs_disabled(): 0, pid: 3658, name: syz-fuzzer 
+`: "BUG: sleeping function called from invalid context at include/linux/wait.h:1095 ",
+		`
+------------[ cut here ]------------
+WARNING: CPU: 3 PID: 1975 at fs/locks.c:241
+locks_free_lock_context+0x118/0x180()
+`: "WARNING: CPU: 3 PID: 1975 at fs/locks.c:241",
+	}
+	for log, crash := range tests {
+		if strings.Index(log, "\r\n") != -1 {
+			continue
+		}
+		tests[strings.Replace(log, "\n", "\r\n", -1)] = crash
+	}
+	for log, crash := range tests {
+		loc := CrashRe.FindStringIndex(log)
+		if loc == nil && crash != "" {
+			t.Fatalf("did not find crash message '%v' in:\n%v", crash, log)
+		}
+		if loc != nil && crash == "" {
+			t.Fatalf("found bogus crash message '%v' in:\n%v", log[loc[0]:loc[1]], log)
+		}
+		if loc == nil {
+			continue
+		}
+		crash1 := log[loc[0]:loc[1]]
+		if crash1 != crash {
+			t.Fatalf("extracted bad crash message:\n%v\nwant:\n%v", crash1, crash)
+		}
+	}
+}