diff options
| -rw-r--r-- | pkg/sentry/fsimpl/kernfs/filesystem.go | 23 | ||||
| -rw-r--r-- | test/syscalls/linux/rename.cc | 14 |
2 files changed, 28 insertions, 9 deletions
diff --git a/pkg/sentry/fsimpl/kernfs/filesystem.go b/pkg/sentry/fsimpl/kernfs/filesystem.go index beb9302f6..badca4d9f 100644 --- a/pkg/sentry/fsimpl/kernfs/filesystem.go +++ b/pkg/sentry/fsimpl/kernfs/filesystem.go @@ -668,14 +668,14 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa // Can we create the dst dentry? var dst *Dentry - pc := rp.Component() - if pc == "." || pc == ".." { + newName := rp.Component() + if newName == "." || newName == ".." { if noReplace { return syserror.EEXIST } return syserror.EBUSY } - switch err := checkCreateLocked(ctx, rp.Credentials(), pc, dstDir); err { + switch err := checkCreateLocked(ctx, rp.Credentials(), newName, dstDir); err { case nil: // Ok, continue with rename as replacement. case syserror.EEXIST: @@ -683,13 +683,18 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa // Won't overwrite existing node since RENAME_NOREPLACE was requested. return syserror.EEXIST } - dst = dstDir.children[pc] + dst = dstDir.children[newName] if dst == nil { - panic(fmt.Sprintf("Child %q for parent Dentry %+v disappeared inside atomic section?", pc, dstDir)) + panic(fmt.Sprintf("Child %q for parent Dentry %+v disappeared inside atomic section?", newName, dstDir)) } default: return err } + + if srcDir == dstDir && oldName == newName { + return nil + } + var dstVFSD *vfs.Dentry if dst != nil { dstVFSD = dst.VFSDentry() @@ -712,7 +717,7 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa if err := virtfs.PrepareRenameDentry(mntns, srcVFSD, dstVFSD); err != nil { return err } - err = srcDir.inode.Rename(ctx, src.name, pc, src.inode, dstDir.inode) + err = srcDir.inode.Rename(ctx, src.name, newName, src.inode, dstDir.inode) if err != nil { virtfs.AbortRenameDentry(srcVFSD, dstVFSD) return err @@ -723,12 +728,12 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa dstDir.IncRef() // child (src) takes a ref on the new parent. } src.parent = dstDir - src.name = pc + src.name = newName if dstDir.children == nil { dstDir.children = make(map[string]*Dentry) } - replaced := dstDir.children[pc] - dstDir.children[pc] = src + replaced := dstDir.children[newName] + dstDir.children[newName] = src var replaceVFSD *vfs.Dentry if replaced != nil { // deferDecRef so that fs.mu and dstDir.mu are unlocked by then. diff --git a/test/syscalls/linux/rename.cc b/test/syscalls/linux/rename.cc index 22c8c19cf..b1a813de0 100644 --- a/test/syscalls/linux/rename.cc +++ b/test/syscalls/linux/rename.cc @@ -424,6 +424,20 @@ TEST(RenameTest, SysfsPathEndingWithDots) { SyscallFailsWithErrno(EBUSY)); } +TEST(RenameTest, SysfsFileToSelf) { + // If a non-root user tries to rename inside /sys then we get EPERM. + SKIP_IF(geteuid() != 0); + std::string const path = "/sys/devices/system/cpu/online"; + EXPECT_THAT(rename(path.c_str(), path.c_str()), SyscallSucceeds()); +} + +TEST(RenameTest, SysfsDirectoryToSelf) { + // If a non-root user tries to rename inside /sys then we get EPERM. + SKIP_IF(geteuid() != 0); + std::string const path = "/sys/devices"; + EXPECT_THAT(rename(path.c_str(), path.c_str()), SyscallSucceeds()); +} + } // namespace } // namespace testing |