Skip to content

Make setting security.capability attribute a no-op in tmpfs. #11605

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

Make setting security.capability attribute a no-op in tmpfs. #11605

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 5 additions & 0 deletions pkg/sentry/fsimpl/overlay/filesystem.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1825,6 +1825,11 @@ func (fs *filesystem) SetXattrAt(ctx context.Context, rp *vfs.ResolvingPath, opt

// Precondition: fs.renameMu must be locked.
func (fs *filesystem) setXattrLocked(ctx context.Context, d *dentry, mnt *vfs.Mount, creds *auth.Credentials, opts *vfs.SetXattrOptions) error {
if strings.HasPrefix(opts.Name, linux.XATTR_SECURITY_PREFIX) {
// TODO(b/301323819): support security extended attributes in overlayfs.
// Setting security extended attributes in overlayfs is a no-op.
return nil
}
if err := d.checkXattrPermissions(creds, opts.Name, vfs.MayWrite); err != nil {
return err
}
Expand Down
5 changes: 5 additions & 0 deletions pkg/sentry/fsimpl/tmpfs/tmpfs.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -870,6 +870,11 @@ func (i *inode) setXattr(creds *auth.Credentials, opts *vfs.SetXattrOptions) err
if err := i.checkXattrPrefix(opts.Name); err != nil {
return err
}
if strings.HasPrefix(opts.Name, linux.XATTR_SECURITY_PREFIX) {
// TODO(b/301323819): support security extended attributes in tmpfs.
// Setting security extended attributes in tmpfs is a no-op.
return nil
}
mode := linux.FileMode(i.mode.Load())
kuid := auth.KUID(i.uid.Load())
kgid := auth.KGID(i.gid.Load())
Expand Down
10 changes: 8 additions & 2 deletions test/syscalls/linux/xattr.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -111,8 +111,14 @@ TEST_F(XattrTest, SecurityCapacityXattr) {
const char* path = test_file_name_.c_str();
const char name[] = "security.capacity";
const std::string val = "";
EXPECT_THAT(lsetxattr(path, name, &val, val.size(), 0),
SyscallFailsWithErrno(EOPNOTSUPP));
if (ASSERT_NO_ERRNO_AND_VALUE(IsTmpfs(test_file_name_)) ||
ASSERT_NO_ERRNO_AND_VALUE(IsOverlayfs(test_file_name_))) {
EXPECT_THAT(lsetxattr(path, name, &val, val.size(), 0), SyscallSucceeds());
} else {
EXPECT_THAT(lsetxattr(path, name, &val, val.size(), 0),
SyscallFailsWithErrno(EOPNOTSUPP));
}

int buf = 0;
EXPECT_THAT(lgetxattr(path, name, &buf, /*size=*/128),
SyscallFailsWithErrno(AnyOf(ENODATA, EOPNOTSUPP)));
Expand Down