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-rw-r--r--pkg/sentry/fs/inode.go4
-rw-r--r--pkg/sentry/fs/tty/master.go1
-rw-r--r--pkg/sentry/fs/tty/slave.go1
-rw-r--r--pkg/sentry/syscalls/linux/sys_file.go9
-rw-r--r--test/syscalls/linux/open.cc22
-rw-r--r--test/syscalls/linux/open_create.cc24
-rw-r--r--test/syscalls/linux/pty.cc20
-rw-r--r--test/util/pty_util.cc10
-rw-r--r--test/util/pty_util.h3
9 files changed, 88 insertions, 6 deletions
diff --git a/pkg/sentry/fs/inode.go b/pkg/sentry/fs/inode.go
index f4ddfa406..2d43dff1d 100644
--- a/pkg/sentry/fs/inode.go
+++ b/pkg/sentry/fs/inode.go
@@ -344,6 +344,10 @@ func (i *Inode) SetTimestamps(ctx context.Context, d *Dirent, ts TimeSpec) error
// Truncate calls i.InodeOperations.Truncate with i as the Inode.
func (i *Inode) Truncate(ctx context.Context, d *Dirent, size int64) error {
+ if IsDir(i.StableAttr) {
+ return syserror.EISDIR
+ }
+
if i.overlay != nil {
return overlayTruncate(ctx, i.overlay, d, size)
}
diff --git a/pkg/sentry/fs/tty/master.go b/pkg/sentry/fs/tty/master.go
index 19b7557d5..bc56be696 100644
--- a/pkg/sentry/fs/tty/master.go
+++ b/pkg/sentry/fs/tty/master.go
@@ -32,6 +32,7 @@ import (
// +stateify savable
type masterInodeOperations struct {
fsutil.SimpleFileInode
+ fsutil.InodeNoopTruncate
// d is the containing dir.
d *dirInodeOperations
diff --git a/pkg/sentry/fs/tty/slave.go b/pkg/sentry/fs/tty/slave.go
index 944c4ada1..4cbea0367 100644
--- a/pkg/sentry/fs/tty/slave.go
+++ b/pkg/sentry/fs/tty/slave.go
@@ -31,6 +31,7 @@ import (
// +stateify savable
type slaveInodeOperations struct {
fsutil.SimpleFileInode
+ fsutil.InodeNoopTruncate
// d is the containing dir.
d *dirInodeOperations
diff --git a/pkg/sentry/syscalls/linux/sys_file.go b/pkg/sentry/syscalls/linux/sys_file.go
index b9a8e3e21..167c2b60b 100644
--- a/pkg/sentry/syscalls/linux/sys_file.go
+++ b/pkg/sentry/syscalls/linux/sys_file.go
@@ -169,10 +169,11 @@ func openAt(t *kernel.Task, dirFD int32, addr usermem.Addr, flags uint) (fd uint
if dirPath {
return syserror.ENOTDIR
}
- if flags&linux.O_TRUNC != 0 {
- if err := d.Inode.Truncate(t, d, 0); err != nil {
- return err
- }
+ }
+
+ if flags&linux.O_TRUNC != 0 {
+ if err := d.Inode.Truncate(t, d, 0); err != nil {
+ return err
}
}
diff --git a/test/syscalls/linux/open.cc b/test/syscalls/linux/open.cc
index 2b1df52ce..267ae19f6 100644
--- a/test/syscalls/linux/open.cc
+++ b/test/syscalls/linux/open.cc
@@ -73,6 +73,28 @@ class OpenTest : public FileTest {
const std::string test_data_ = "hello world\n";
};
+TEST_F(OpenTest, OTrunc) {
+ auto dirpath = JoinPath(GetAbsoluteTestTmpdir(), "truncd");
+ ASSERT_THAT(mkdir(dirpath.c_str(), 0777), SyscallSucceeds());
+ ASSERT_THAT(open(dirpath.c_str(), O_TRUNC, 0666),
+ SyscallFailsWithErrno(EISDIR));
+}
+
+TEST_F(OpenTest, OTruncAndReadOnlyDir) {
+ auto dirpath = JoinPath(GetAbsoluteTestTmpdir(), "truncd");
+ ASSERT_THAT(mkdir(dirpath.c_str(), 0777), SyscallSucceeds());
+ ASSERT_THAT(open(dirpath.c_str(), O_TRUNC | O_RDONLY, 0666),
+ SyscallFailsWithErrno(EISDIR));
+}
+
+TEST_F(OpenTest, OTruncAndReadOnlyFile) {
+ auto dirpath = JoinPath(GetAbsoluteTestTmpdir(), "truncfile");
+ const FileDescriptor existing =
+ ASSERT_NO_ERRNO_AND_VALUE(Open(dirpath.c_str(), O_RDWR | O_CREAT, 0666));
+ const FileDescriptor otrunc = ASSERT_NO_ERRNO_AND_VALUE(
+ Open(dirpath.c_str(), O_TRUNC | O_RDONLY, 0666));
+}
+
TEST_F(OpenTest, ReadOnly) {
char buf;
const FileDescriptor ro_file =
diff --git a/test/syscalls/linux/open_create.cc b/test/syscalls/linux/open_create.cc
index e5a85ef9d..431733dbe 100644
--- a/test/syscalls/linux/open_create.cc
+++ b/test/syscalls/linux/open_create.cc
@@ -88,6 +88,30 @@ TEST(CreateTest, CreateExclusively) {
SyscallFailsWithErrno(EEXIST));
}
+TEST(CreateTeast, CreatWithOTrunc) {
+ std::string dirpath = JoinPath(GetAbsoluteTestTmpdir(), "truncd");
+ ASSERT_THAT(mkdir(dirpath.c_str(), 0777), SyscallSucceeds());
+ ASSERT_THAT(open(dirpath.c_str(), O_CREAT | O_TRUNC, 0666),
+ SyscallFailsWithErrno(EISDIR));
+}
+
+TEST(CreateTeast, CreatDirWithOTruncAndReadOnly) {
+ std::string dirpath = JoinPath(GetAbsoluteTestTmpdir(), "truncd");
+ ASSERT_THAT(mkdir(dirpath.c_str(), 0777), SyscallSucceeds());
+ ASSERT_THAT(open(dirpath.c_str(), O_CREAT | O_TRUNC | O_RDONLY, 0666),
+ SyscallFailsWithErrno(EISDIR));
+}
+
+TEST(CreateTeast, CreatFileWithOTruncAndReadOnly) {
+ std::string dirpath = JoinPath(GetAbsoluteTestTmpdir(), "truncfile");
+ int dirfd;
+ ASSERT_THAT(dirfd = open(dirpath.c_str(), O_RDWR | O_CREAT, 0666),
+ SyscallSucceeds());
+ ASSERT_THAT(open(dirpath.c_str(), O_CREAT | O_TRUNC | O_RDONLY, 0666),
+ SyscallSucceeds());
+ ASSERT_THAT(close(dirfd), SyscallSucceeds());
+}
+
TEST(CreateTest, CreateFailsOnUnpermittedDir) {
// Make sure we don't have CAP_DAC_OVERRIDE, since that allows the user to
// always override directory permissions.
diff --git a/test/syscalls/linux/pty.cc b/test/syscalls/linux/pty.cc
index 99a0df235..dafe64d20 100644
--- a/test/syscalls/linux/pty.cc
+++ b/test/syscalls/linux/pty.cc
@@ -70,6 +70,8 @@ constexpr absl::Duration kTimeout = absl::Seconds(20);
// The maximum line size in bytes returned per read from a pty file.
constexpr int kMaxLineSize = 4096;
+constexpr char kMasterPath[] = "/dev/ptmx";
+
// glibc defines its own, different, version of struct termios. We care about
// what the kernel does, not glibc.
#define KERNEL_NCCS 19
@@ -376,9 +378,25 @@ PosixErrorOr<size_t> PollAndReadFd(int fd, void* buf, size_t count,
return PosixError(ETIMEDOUT, "Poll timed out");
}
+TEST(PtyTrunc, Truncate) {
+ // Opening PTYs with O_TRUNC shouldn't cause an error, but calls to
+ // (f)truncate should.
+ FileDescriptor master =
+ ASSERT_NO_ERRNO_AND_VALUE(Open(kMasterPath, O_RDWR | O_TRUNC));
+ int n = ASSERT_NO_ERRNO_AND_VALUE(SlaveID(master));
+ std::string spath = absl::StrCat("/dev/pts/", n);
+ FileDescriptor slave =
+ ASSERT_NO_ERRNO_AND_VALUE(Open(spath, O_RDWR | O_NONBLOCK | O_TRUNC));
+
+ EXPECT_THAT(truncate(kMasterPath, 0), SyscallFailsWithErrno(EINVAL));
+ EXPECT_THAT(truncate(spath.c_str(), 0), SyscallFailsWithErrno(EINVAL));
+ EXPECT_THAT(ftruncate(master.get(), 0), SyscallFailsWithErrno(EINVAL));
+ EXPECT_THAT(ftruncate(slave.get(), 0), SyscallFailsWithErrno(EINVAL));
+}
+
TEST(BasicPtyTest, StatUnopenedMaster) {
struct stat s;
- ASSERT_THAT(stat("/dev/ptmx", &s), SyscallSucceeds());
+ ASSERT_THAT(stat(kMasterPath, &s), SyscallSucceeds());
EXPECT_EQ(s.st_rdev, makedev(TTYAUX_MAJOR, kPtmxMinor));
EXPECT_EQ(s.st_size, 0);
diff --git a/test/util/pty_util.cc b/test/util/pty_util.cc
index c0fd9a095..c01f916aa 100644
--- a/test/util/pty_util.cc
+++ b/test/util/pty_util.cc
@@ -24,6 +24,14 @@ namespace gvisor {
namespace testing {
PosixErrorOr<FileDescriptor> OpenSlave(const FileDescriptor& master) {
+ PosixErrorOr<int> n = SlaveID(master);
+ if (!n.ok()) {
+ return PosixErrorOr<FileDescriptor>(n.error());
+ }
+ return Open(absl::StrCat("/dev/pts/", n.ValueOrDie()), O_RDWR | O_NONBLOCK);
+}
+
+PosixErrorOr<int> SlaveID(const FileDescriptor& master) {
// Get pty index.
int n;
int ret = ioctl(master.get(), TIOCGPTN, &n);
@@ -38,7 +46,7 @@ PosixErrorOr<FileDescriptor> OpenSlave(const FileDescriptor& master) {
return PosixError(errno, "ioctl(TIOSPTLCK) failed");
}
- return Open(absl::StrCat("/dev/pts/", n), O_RDWR | O_NONBLOCK);
+ return n;
}
} // namespace testing
diff --git a/test/util/pty_util.h b/test/util/pty_util.h
index 367b14f15..0722da379 100644
--- a/test/util/pty_util.h
+++ b/test/util/pty_util.h
@@ -24,6 +24,9 @@ namespace testing {
// Opens the slave end of the passed master as R/W and nonblocking.
PosixErrorOr<FileDescriptor> OpenSlave(const FileDescriptor& master);
+// Get the number of the slave end of the master.
+PosixErrorOr<int> SlaveID(const FileDescriptor& master);
+
} // namespace testing
} // namespace gvisor
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-02 02:20:34 +0000