diff options
| author | Michael Pratt <mpratt@google.com> | 2019-03-18 18:39:08 -0700 |
|---|---|---|
| committer | Shentubot <shentubot@google.com> | 2019-03-18 18:40:06 -0700 |
| commit | 8a499ae65f361fb01c2e4be03122f69910a8ba4a (patch) | |
| tree | 6b217045a189f94b9bd62756fe61bf40f34d622f /pkg/sentry/fs/gofer | |
| parent | e420cc3e5d2066674d32d16ad885bee6b30da210 (diff) | |
Remove references to replaced child in Rename in ramfs/agentfs
In the case of a rename replacing an existing destination inode, ramfs
Rename failed to first remove the replaced inode. This caused:
1. A leak of a reference to the inode (making it live indefinitely).
2. For directories, a leak of the replaced directory's .. link to the
parent. This would cause the parent's link count to incorrectly
increase.
(2) is much simpler to test than (1), so that's what I've done.
agentfs has a similar bug with link count only, so the Dirent layer
informs the Inode if this is a replacing rename.
Fixes #133
PiperOrigin-RevId: 239105698
Change-Id: I4450af2462d8ae3339def812287213d2cbeebde0
Diffstat (limited to 'pkg/sentry/fs/gofer')
| -rw-r--r-- | pkg/sentry/fs/gofer/path.go | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/pkg/sentry/fs/gofer/path.go b/pkg/sentry/fs/gofer/path.go index 43f990d16..2ba400836 100644 --- a/pkg/sentry/fs/gofer/path.go +++ b/pkg/sentry/fs/gofer/path.go @@ -298,7 +298,7 @@ func (i *inodeOperations) RemoveDirectory(ctx context.Context, dir *fs.Inode, na } // Rename renames this node. -func (i *inodeOperations) Rename(ctx context.Context, oldParent *fs.Inode, oldName string, newParent *fs.Inode, newName string) error { +func (i *inodeOperations) Rename(ctx context.Context, oldParent *fs.Inode, oldName string, newParent *fs.Inode, newName string, replacement bool) error { // Unwrap the new parent to a *inodeOperations. newParentInodeOperations, ok := newParent.InodeOperations.(*inodeOperations) if !ok { @@ -323,7 +323,12 @@ func (i *inodeOperations) Rename(ctx context.Context, oldParent *fs.Inode, oldNa oldParentInodeOperations.cachingInodeOps.DecLinks(ctx) } if i.session().cachePolicy.cacheUAttrs(newParent) { - newParentInodeOperations.cachingInodeOps.IncLinks(ctx) + // Only IncLinks if there is a new addition to + // newParent. If this is replacement, then the total + // count remains the same. + if !replacement { + newParentInodeOperations.cachingInodeOps.IncLinks(ctx) + } } } if i.session().cachePolicy.cacheReaddir() { |