diff options
| author | gVisor bot <gvisor-bot@google.com> | 2020-06-09 17:00:50 -0700 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2020-06-09 17:02:14 -0700 |
| commit | 4950ccde75b3a85852f10bce6a76f033cf2f9ac6 (patch) | |
| tree | 3198488d7d4e459c1f11ef2da834d360bee17ea0 /test/syscalls/linux | |
| parent | 6722b1e56fa63f3409f222a63241705aa3f3ace4 (diff) | |
Fix write hang bug found by syzkaller.
After this change e.mu is only promoted to exclusively locked during
route.Resolve. It downgrades back to read-lock afterwards.
This prevents the second RLock() call gets stuck later in the stack.
https://syzkaller.appspot.com/bug?id=065b893bd8d1d04a4e0a1d53c578537cde1efe99
Syzkaller logs does not contain interesting stack traces.
The following stack trace is obtained by running repro locally.
goroutine 53 [semacquire, 3 minutes]:
runtime.gopark(0xfd4278, 0x1896320, 0xc000301912, 0x4)
GOROOT/src/runtime/proc.go:304 +0xe0 fp=0xc0000e25f8 sp=0xc0000e25d8 pc=0x437170
runtime.goparkunlock(...)
GOROOT/src/runtime/proc.go:310
runtime.semacquire1(0xc0001220b0, 0xc00000a300, 0x1, 0x0)
GOROOT/src/runtime/sema.go:144 +0x1c0 fp=0xc0000e2660 sp=0xc0000e25f8 pc=0x4484e0
sync.runtime_Semacquire(0xc0001220b0)
GOROOT/src/runtime/sema.go:56 +0x42 fp=0xc0000e2690 sp=0xc0000e2660 pc=0x448132
gvisor.dev/gvisor/pkg/sync.(*RWMutex).RLock(...)
pkg/sync/rwmutex_unsafe.go:76
gvisor.dev/gvisor/pkg/tcpip/transport/udp.(*endpoint).HandleControlPacket(0xc000122000, 0x7ee5, 0xc00053c16c, 0x4, 0x5e21, 0xc00053c224, 0x4, 0x1, 0x0, 0xc00007ed00)
pkg/tcpip/transport/udp/endpoint.go:1345 +0x169 fp=0xc0000e26d8 sp=0xc0000e2690 pc=0x9843f9
......
gvisor.dev/gvisor/pkg/tcpip/transport/udp.(*protocol).HandleUnknownDestinationPacket(0x18bb5a0, 0xc000556540, 0x5e21, 0xc00053c16c, 0x4, 0x7ee5, 0xc00053c1ec, 0x4, 0xc00007e680, 0x4)
pkg/tcpip/transport/udp/protocol.go:143 +0xb9a fp=0xc0000e8260 sp=0xc0000e7510 pc=0x9859ba
......
gvisor.dev/gvisor/pkg/tcpip/transport/udp.sendUDP(0xc0001220d0, 0xc00053ece0, 0x1, 0x1, 0x883, 0x1405e217ee5, 0x11100a0, 0xc000592000, 0xf88780)
pkg/tcpip/transport/udp/endpoint.go:924 +0x3b0 fp=0xc0000ed390 sp=0xc0000ec750 pc=0x981af0
gvisor.dev/gvisor/pkg/tcpip/transport/udp.(*endpoint).write(0xc000122000, 0x11104e0, 0xc00020a460, 0x0, 0x0, 0x0, 0x0, 0x0)
pkg/tcpip/transport/udp/endpoint.go:510 +0x4ad fp=0xc0000ed658 sp=0xc0000ed390 pc=0x97f2dd
PiperOrigin-RevId: 315590041
Diffstat (limited to 'test/syscalls/linux')
| -rw-r--r-- | test/syscalls/linux/tuntap.cc | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/test/syscalls/linux/tuntap.cc b/test/syscalls/linux/tuntap.cc index 6195b11e1..97d554e72 100644 --- a/test/syscalls/linux/tuntap.cc +++ b/test/syscalls/linux/tuntap.cc @@ -398,5 +398,25 @@ TEST_F(TuntapTest, SendUdpTriggersArpResolution) { } } +// Write hang bug found by syskaller: b/155928773 +// https://syzkaller.appspot.com/bug?id=065b893bd8d1d04a4e0a1d53c578537cde1efe99 +TEST_F(TuntapTest, WriteHangBug155928773) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_ADMIN))); + + FileDescriptor fd = + ASSERT_NO_ERRNO_AND_VALUE(OpenAndAttachTap(kTapName, "10.0.0.1")); + + int sock = socket(AF_INET, SOCK_DGRAM, 0); + ASSERT_THAT(sock, SyscallSucceeds()); + + struct sockaddr_in remote = {}; + remote.sin_family = AF_INET; + remote.sin_port = htons(42); + inet_pton(AF_INET, "10.0.0.1", &remote.sin_addr); + // Return values do not matter in this test. + connect(sock, reinterpret_cast<struct sockaddr*>(&remote), sizeof(remote)); + write(sock, "hello", 5); +} + } // namespace testing } // namespace gvisor |