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-rw-r--r--pkg/sentry/fs/attr.go14
-rw-r--r--pkg/sentry/fs/dev/dev.go8
-rw-r--r--pkg/sentry/fs/fsutil/host_mappable.go21
-rw-r--r--pkg/sentry/fs/fsutil/inode_cached.go27
-rw-r--r--pkg/sentry/fs/gofer/BUILD1
-rw-r--r--pkg/sentry/fs/gofer/cache_policy.go2
-rw-r--r--pkg/sentry/fs/gofer/file.go19
-rw-r--r--pkg/sentry/fs/gofer/inode.go18
-rw-r--r--pkg/sentry/fs/gofer/path.go20
-rw-r--r--pkg/sentry/fs/proc/sys.go22
-rw-r--r--pkg/sentry/fs/proc/sys_net.go16
-rw-r--r--pkg/sentry/fs/proc/sys_net_state.go6
-rw-r--r--pkg/sentry/fs/tmpfs/fs.go2
-rw-r--r--pkg/sentry/fs/tmpfs/inode_file.go15
-rw-r--r--pkg/sentry/fs/tmpfs/tmpfs.go31
-rw-r--r--pkg/sentry/fs/user/user_test.go5
16 files changed, 186 insertions, 41 deletions
diff --git a/pkg/sentry/fs/attr.go b/pkg/sentry/fs/attr.go
index b90f7c1be..4c99944e7 100644
--- a/pkg/sentry/fs/attr.go
+++ b/pkg/sentry/fs/attr.go
@@ -478,6 +478,20 @@ func (f FilePermissions) AnyRead() bool {
return f.User.Read || f.Group.Read || f.Other.Read
}
+// HasSetUIDOrGID returns true if either the setuid or setgid bit is set.
+func (f FilePermissions) HasSetUIDOrGID() bool {
+ return f.SetUID || f.SetGID
+}
+
+// DropSetUIDAndMaybeGID turns off setuid, and turns off setgid if f allows
+// group execution.
+func (f *FilePermissions) DropSetUIDAndMaybeGID() {
+ f.SetUID = false
+ if f.Group.Execute {
+ f.SetGID = false
+ }
+}
+
// FileOwner represents ownership of a file.
//
// +stateify savable
diff --git a/pkg/sentry/fs/dev/dev.go b/pkg/sentry/fs/dev/dev.go
index e84ba7a5d..c62effd52 100644
--- a/pkg/sentry/fs/dev/dev.go
+++ b/pkg/sentry/fs/dev/dev.go
@@ -16,6 +16,7 @@
package dev
import (
+ "fmt"
"math"
"gvisor.dev/gvisor/pkg/context"
@@ -90,6 +91,11 @@ func newSymlink(ctx context.Context, target string, msrc *fs.MountSource) *fs.In
// New returns the root node of a device filesystem.
func New(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
+ shm, err := tmpfs.NewDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0777), msrc, nil /* parent */)
+ if err != nil {
+ panic(fmt.Sprintf("tmpfs.NewDir failed: %v", err))
+ }
+
contents := map[string]*fs.Inode{
"fd": newSymlink(ctx, "/proc/self/fd", msrc),
"stdin": newSymlink(ctx, "/proc/self/fd/0", msrc),
@@ -108,7 +114,7 @@ func New(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
"random": newMemDevice(ctx, newRandomDevice(ctx, fs.RootOwner, 0444), msrc, randomDevMinor),
"urandom": newMemDevice(ctx, newRandomDevice(ctx, fs.RootOwner, 0444), msrc, urandomDevMinor),
- "shm": tmpfs.NewDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0777), msrc),
+ "shm": shm,
// A devpts is typically mounted at /dev/pts to provide
// pseudoterminal support. Place an empty directory there for
diff --git a/pkg/sentry/fs/fsutil/host_mappable.go b/pkg/sentry/fs/fsutil/host_mappable.go
index e1e38b498..8ac3738e9 100644
--- a/pkg/sentry/fs/fsutil/host_mappable.go
+++ b/pkg/sentry/fs/fsutil/host_mappable.go
@@ -155,12 +155,20 @@ func (h *HostMappable) DecRef(fr memmap.FileRange) {
// T2: Appends to file causing it to grow
// T2: Writes to mapped pages and COW happens
// T1: Continues and wronly invalidates the page mapped in step above.
-func (h *HostMappable) Truncate(ctx context.Context, newSize int64) error {
+func (h *HostMappable) Truncate(ctx context.Context, newSize int64, uattr fs.UnstableAttr) error {
h.truncateMu.Lock()
defer h.truncateMu.Unlock()
mask := fs.AttrMask{Size: true}
attr := fs.UnstableAttr{Size: newSize}
+
+ // Truncating a file clears privilege bits.
+ if uattr.Perms.HasSetUIDOrGID() {
+ mask.Perms = true
+ attr.Perms = uattr.Perms
+ attr.Perms.DropSetUIDAndMaybeGID()
+ }
+
if err := h.backingFile.SetMaskedAttributes(ctx, mask, attr, false); err != nil {
return err
}
@@ -193,10 +201,17 @@ func (h *HostMappable) Allocate(ctx context.Context, offset int64, length int64)
}
// Write writes to the file backing this mappable.
-func (h *HostMappable) Write(ctx context.Context, src usermem.IOSequence, offset int64) (int64, error) {
+func (h *HostMappable) Write(ctx context.Context, src usermem.IOSequence, offset int64, uattr fs.UnstableAttr) (int64, error) {
h.truncateMu.RLock()
+ defer h.truncateMu.RUnlock()
n, err := src.CopyInTo(ctx, &writer{ctx: ctx, hostMappable: h, off: offset})
- h.truncateMu.RUnlock()
+ if n > 0 && uattr.Perms.HasSetUIDOrGID() {
+ mask := fs.AttrMask{Perms: true}
+ uattr.Perms.DropSetUIDAndMaybeGID()
+ if err := h.backingFile.SetMaskedAttributes(ctx, mask, uattr, false); err != nil {
+ return n, err
+ }
+ }
return n, err
}
diff --git a/pkg/sentry/fs/fsutil/inode_cached.go b/pkg/sentry/fs/fsutil/inode_cached.go
index 7856b354b..855029b84 100644
--- a/pkg/sentry/fs/fsutil/inode_cached.go
+++ b/pkg/sentry/fs/fsutil/inode_cached.go
@@ -310,6 +310,12 @@ func (c *CachingInodeOperations) Truncate(ctx context.Context, inode *fs.Inode,
now := ktime.NowFromContext(ctx)
masked := fs.AttrMask{Size: true}
attr := fs.UnstableAttr{Size: size}
+ if c.attr.Perms.HasSetUIDOrGID() {
+ masked.Perms = true
+ attr.Perms = c.attr.Perms
+ attr.Perms.DropSetUIDAndMaybeGID()
+ c.attr.Perms = attr.Perms
+ }
if err := c.backingFile.SetMaskedAttributes(ctx, masked, attr, false); err != nil {
c.dataMu.Unlock()
return err
@@ -685,13 +691,14 @@ func (rw *inodeReadWriter) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) {
return done, nil
}
-// maybeGrowFile grows the file's size if data has been written past the old
-// size.
+// maybeUpdateAttrs updates the file's attributes after a write. It updates
+// size if data has been written past the old size, and setuid/setgid if any
+// bytes were written.
//
// Preconditions:
// * rw.c.attrMu must be locked.
// * rw.c.dataMu must be locked.
-func (rw *inodeReadWriter) maybeGrowFile() {
+func (rw *inodeReadWriter) maybeUpdateAttrs(nwritten uint64) {
// If the write ends beyond the file's previous size, it causes the
// file to grow.
if rw.offset > rw.c.attr.Size {
@@ -705,6 +712,12 @@ func (rw *inodeReadWriter) maybeGrowFile() {
rw.c.attr.Usage = rw.offset
rw.c.dirtyAttr.Usage = true
}
+
+ // If bytes were written, ensure setuid and setgid are cleared.
+ if nwritten > 0 && rw.c.attr.Perms.HasSetUIDOrGID() {
+ rw.c.dirtyAttr.Perms = true
+ rw.c.attr.Perms.DropSetUIDAndMaybeGID()
+ }
}
// WriteFromBlocks implements safemem.Writer.WriteFromBlocks.
@@ -732,7 +745,7 @@ func (rw *inodeReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error
segMR := seg.Range().Intersect(mr)
ims, err := mf.MapInternal(seg.FileRangeOf(segMR), hostarch.Write)
if err != nil {
- rw.maybeGrowFile()
+ rw.maybeUpdateAttrs(done)
rw.c.dataMu.Unlock()
return done, err
}
@@ -744,7 +757,7 @@ func (rw *inodeReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error
srcs = srcs.DropFirst64(n)
rw.c.dirty.MarkDirty(segMR)
if err != nil {
- rw.maybeGrowFile()
+ rw.maybeUpdateAttrs(done)
rw.c.dataMu.Unlock()
return done, err
}
@@ -765,7 +778,7 @@ func (rw *inodeReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error
srcs = srcs.DropFirst64(n)
// Partial writes are fine. But we must stop writing.
if n != src.NumBytes() || err != nil {
- rw.maybeGrowFile()
+ rw.maybeUpdateAttrs(done)
rw.c.dataMu.Unlock()
return done, err
}
@@ -774,7 +787,7 @@ func (rw *inodeReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error
seg, gap = gap.NextSegment(), FileRangeGapIterator{}
}
}
- rw.maybeGrowFile()
+ rw.maybeUpdateAttrs(done)
rw.c.dataMu.Unlock()
return done, nil
}
diff --git a/pkg/sentry/fs/gofer/BUILD b/pkg/sentry/fs/gofer/BUILD
index c4a069832..94cb05246 100644
--- a/pkg/sentry/fs/gofer/BUILD
+++ b/pkg/sentry/fs/gofer/BUILD
@@ -29,6 +29,7 @@ go_library(
"//pkg/fd",
"//pkg/hostarch",
"//pkg/log",
+ "//pkg/metric",
"//pkg/p9",
"//pkg/refs",
"//pkg/safemem",
diff --git a/pkg/sentry/fs/gofer/cache_policy.go b/pkg/sentry/fs/gofer/cache_policy.go
index 07a564e92..f8b7a60fc 100644
--- a/pkg/sentry/fs/gofer/cache_policy.go
+++ b/pkg/sentry/fs/gofer/cache_policy.go
@@ -139,7 +139,7 @@ func (cp cachePolicy) revalidate(ctx context.Context, name string, parent, child
// Walk from parent to child again.
//
- // TODO(b/112031682): If we have a directory FD in the parent
+ // NOTE(b/112031682): If we have a directory FD in the parent
// inodeOperations, then we can use fstatat(2) to get the inode
// attributes instead of making this RPC.
qids, f, mask, attr, err := parentIops.fileState.file.walkGetAttr(ctx, []string{name})
diff --git a/pkg/sentry/fs/gofer/file.go b/pkg/sentry/fs/gofer/file.go
index 8f5a87120..73d80d9b5 100644
--- a/pkg/sentry/fs/gofer/file.go
+++ b/pkg/sentry/fs/gofer/file.go
@@ -21,6 +21,7 @@ import (
"golang.org/x/sys/unix"
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/log"
+ "gvisor.dev/gvisor/pkg/metric"
"gvisor.dev/gvisor/pkg/p9"
"gvisor.dev/gvisor/pkg/sentry/device"
"gvisor.dev/gvisor/pkg/sentry/fs"
@@ -91,7 +92,7 @@ func NewFile(ctx context.Context, dirent *fs.Dirent, name string, flags fs.FileF
}
if flags.Write {
if err := dirent.Inode.CheckPermission(ctx, fs.PermMask{Execute: true}); err == nil {
- fsmetric.GoferOpensWX.Increment()
+ metric.SuspiciousOperationsMetric.Increment("opened_write_execute_file")
log.Warningf("Opened a writable executable: %q", name)
}
}
@@ -236,10 +237,20 @@ func (f *fileOperations) Write(ctx context.Context, file *fs.File, src usermem.I
// and availability of a host-mappable FD.
if f.inodeOperations.session().cachePolicy.useCachingInodeOps(file.Dirent.Inode) {
n, err = f.inodeOperations.cachingInodeOps.Write(ctx, src, offset)
- } else if f.inodeOperations.fileState.hostMappable != nil {
- n, err = f.inodeOperations.fileState.hostMappable.Write(ctx, src, offset)
} else {
- n, err = src.CopyInTo(ctx, f.handles.readWriterAt(ctx, offset))
+ uattr, e := f.UnstableAttr(ctx, file)
+ if e != nil {
+ return 0, e
+ }
+ if f.inodeOperations.fileState.hostMappable != nil {
+ n, err = f.inodeOperations.fileState.hostMappable.Write(ctx, src, offset, uattr)
+ } else {
+ n, err = src.CopyInTo(ctx, f.handles.readWriterAt(ctx, offset))
+ if n > 0 && uattr.Perms.HasSetUIDOrGID() {
+ uattr.Perms.DropSetUIDAndMaybeGID()
+ f.inodeOperations.SetPermissions(ctx, file.Dirent.Inode, uattr.Perms)
+ }
+ }
}
if n == 0 {
diff --git a/pkg/sentry/fs/gofer/inode.go b/pkg/sentry/fs/gofer/inode.go
index b97635ec4..da3178527 100644
--- a/pkg/sentry/fs/gofer/inode.go
+++ b/pkg/sentry/fs/gofer/inode.go
@@ -600,11 +600,25 @@ func (i *inodeOperations) Truncate(ctx context.Context, inode *fs.Inode, length
if i.session().cachePolicy.useCachingInodeOps(inode) {
return i.cachingInodeOps.Truncate(ctx, inode, length)
}
+
+ uattr, err := i.fileState.unstableAttr(ctx)
+ if err != nil {
+ return err
+ }
+
if i.session().cachePolicy == cacheRemoteRevalidating {
- return i.fileState.hostMappable.Truncate(ctx, length)
+ return i.fileState.hostMappable.Truncate(ctx, length, uattr)
+ }
+
+ mask := p9.SetAttrMask{Size: true}
+ attr := p9.SetAttr{Size: uint64(length)}
+ if uattr.Perms.HasSetUIDOrGID() {
+ mask.Permissions = true
+ uattr.Perms.DropSetUIDAndMaybeGID()
+ attr.Permissions = p9.FileMode(uattr.Perms.LinuxMode())
}
- return i.fileState.file.setAttr(ctx, p9.SetAttrMask{Size: true}, p9.SetAttr{Size: uint64(length)})
+ return i.fileState.file.setAttr(ctx, mask, attr)
}
// GetXattr implements fs.InodeOperations.GetXattr.
diff --git a/pkg/sentry/fs/gofer/path.go b/pkg/sentry/fs/gofer/path.go
index 6b3627813..940838a44 100644
--- a/pkg/sentry/fs/gofer/path.go
+++ b/pkg/sentry/fs/gofer/path.go
@@ -130,7 +130,16 @@ func (i *inodeOperations) Create(ctx context.Context, dir *fs.Inode, name string
panic(fmt.Sprintf("Create called with unknown or unset open flags: %v", flags))
}
+ // If the parent directory has setgid enabled, change the new file's owner.
owner := fs.FileOwnerFromContext(ctx)
+ parentUattr, err := dir.UnstableAttr(ctx)
+ if err != nil {
+ return nil, err
+ }
+ if parentUattr.Perms.SetGID {
+ owner.GID = parentUattr.Owner.GID
+ }
+
hostFile, err := newFile.create(ctx, name, openFlags, p9.FileMode(perm.LinuxMode()), p9.UID(owner.UID), p9.GID(owner.GID))
if err != nil {
// Could not create the file.
@@ -225,7 +234,18 @@ func (i *inodeOperations) CreateDirectory(ctx context.Context, dir *fs.Inode, s
return syserror.ENAMETOOLONG
}
+ // If the parent directory has setgid enabled, change the new directory's
+ // owner and enable setgid.
owner := fs.FileOwnerFromContext(ctx)
+ parentUattr, err := dir.UnstableAttr(ctx)
+ if err != nil {
+ return err
+ }
+ if parentUattr.Perms.SetGID {
+ owner.GID = parentUattr.Owner.GID
+ perm.SetGID = true
+ }
+
if _, err := i.fileState.file.mkdir(ctx, s, p9.FileMode(perm.LinuxMode()), p9.UID(owner.UID), p9.GID(owner.GID)); err != nil {
return err
}
diff --git a/pkg/sentry/fs/proc/sys.go b/pkg/sentry/fs/proc/sys.go
index b998fb75d..085aa6d61 100644
--- a/pkg/sentry/fs/proc/sys.go
+++ b/pkg/sentry/fs/proc/sys.go
@@ -77,6 +77,27 @@ func (*overcommitMemory) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandl
}, 0
}
+// +stateify savable
+type maxMapCount struct{}
+
+// NeedsUpdate implements seqfile.SeqSource.
+func (*maxMapCount) NeedsUpdate(int64) bool {
+ return true
+}
+
+// ReadSeqFileData implements seqfile.SeqSource.
+func (*maxMapCount) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]seqfile.SeqData, int64) {
+ if h != nil {
+ return nil, 0
+ }
+ return []seqfile.SeqData{
+ {
+ Buf: []byte("2147483647\n"),
+ Handle: (*maxMapCount)(nil),
+ },
+ }, 0
+}
+
func (p *proc) newKernelDir(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
h := hostname{
SimpleFileInode: *fsutil.NewSimpleFileInode(ctx, fs.RootOwner, fs.FilePermsFromMode(0444), linux.PROC_SUPER_MAGIC),
@@ -96,6 +117,7 @@ func (p *proc) newKernelDir(ctx context.Context, msrc *fs.MountSource) *fs.Inode
func (p *proc) newVMDir(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
children := map[string]*fs.Inode{
+ "max_map_count": seqfile.NewSeqFileInode(ctx, &maxMapCount{}, msrc),
"mmap_min_addr": seqfile.NewSeqFileInode(ctx, &mmapMinAddrData{p.k}, msrc),
"overcommit_memory": seqfile.NewSeqFileInode(ctx, &overcommitMemory{}, msrc),
}
diff --git a/pkg/sentry/fs/proc/sys_net.go b/pkg/sentry/fs/proc/sys_net.go
index 1d09afdd7..4893af56b 100644
--- a/pkg/sentry/fs/proc/sys_net.go
+++ b/pkg/sentry/fs/proc/sys_net.go
@@ -403,7 +403,7 @@ type ipForwarding struct {
// enabled stores the IPv4 forwarding state on save.
// We must save/restore this here, since a netstack instance
// is created on restore.
- enabled *bool
+ enabled bool
}
func newIPForwardingInode(ctx context.Context, msrc *fs.MountSource, s inet.Stack) *fs.Inode {
@@ -461,13 +461,8 @@ func (f *ipForwardingFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOS
return 0, io.EOF
}
- if f.ipf.enabled == nil {
- enabled := f.stack.Forwarding(ipv4.ProtocolNumber)
- f.ipf.enabled = &enabled
- }
-
val := "0\n"
- if *f.ipf.enabled {
+ if f.ipf.enabled {
// Technically, this is not quite compatible with Linux. Linux
// stores these as an integer, so if you write "2" into
// ip_forward, you should get 2 back.
@@ -494,11 +489,8 @@ func (f *ipForwardingFile) Write(ctx context.Context, _ *fs.File, src usermem.IO
if err != nil {
return n, err
}
- if f.ipf.enabled == nil {
- f.ipf.enabled = new(bool)
- }
- *f.ipf.enabled = v != 0
- return n, f.stack.SetForwarding(ipv4.ProtocolNumber, *f.ipf.enabled)
+ f.ipf.enabled = v != 0
+ return n, f.stack.SetForwarding(ipv4.ProtocolNumber, f.ipf.enabled)
}
// portRangeInode implements fs.InodeOperations. It provides and allows
diff --git a/pkg/sentry/fs/proc/sys_net_state.go b/pkg/sentry/fs/proc/sys_net_state.go
index 4cb4741af..51d2be647 100644
--- a/pkg/sentry/fs/proc/sys_net_state.go
+++ b/pkg/sentry/fs/proc/sys_net_state.go
@@ -47,9 +47,7 @@ func (s *tcpSack) afterLoad() {
// afterLoad is invoked by stateify.
func (ipf *ipForwarding) afterLoad() {
- if ipf.enabled != nil {
- if err := ipf.stack.SetForwarding(ipv4.ProtocolNumber, *ipf.enabled); err != nil {
- panic(fmt.Sprintf("failed to set IPv4 forwarding [%v]: %v", *ipf.enabled, err))
- }
+ if err := ipf.stack.SetForwarding(ipv4.ProtocolNumber, ipf.enabled); err != nil {
+ panic(fmt.Sprintf("ipf.stack.SetForwarding(%d, %t): %s", ipv4.ProtocolNumber, ipf.enabled, err))
}
}
diff --git a/pkg/sentry/fs/tmpfs/fs.go b/pkg/sentry/fs/tmpfs/fs.go
index bc117ca6a..b48d475ed 100644
--- a/pkg/sentry/fs/tmpfs/fs.go
+++ b/pkg/sentry/fs/tmpfs/fs.go
@@ -151,5 +151,5 @@ func (f *Filesystem) Mount(ctx context.Context, device string, flags fs.MountSou
}
// Construct the tmpfs root.
- return NewDir(ctx, nil, owner, perms, msrc), nil
+ return NewDir(ctx, nil, owner, perms, msrc, nil /* parent */)
}
diff --git a/pkg/sentry/fs/tmpfs/inode_file.go b/pkg/sentry/fs/tmpfs/inode_file.go
index f4de8c968..7faa822f0 100644
--- a/pkg/sentry/fs/tmpfs/inode_file.go
+++ b/pkg/sentry/fs/tmpfs/inode_file.go
@@ -226,6 +226,12 @@ func (f *fileInodeOperations) Truncate(ctx context.Context, _ *fs.Inode, size in
now := ktime.NowFromContext(ctx)
f.attr.ModificationTime = now
f.attr.StatusChangeTime = now
+
+ // Truncating clears privilege bits.
+ f.attr.Perms.SetUID = false
+ if f.attr.Perms.Group.Execute {
+ f.attr.Perms.SetGID = false
+ }
}
f.dataMu.Unlock()
@@ -363,7 +369,14 @@ func (f *fileInodeOperations) write(ctx context.Context, src usermem.IOSequence,
now := ktime.NowFromContext(ctx)
f.attr.ModificationTime = now
f.attr.StatusChangeTime = now
- return src.CopyInTo(ctx, &fileReadWriter{f, offset})
+ nwritten, err := src.CopyInTo(ctx, &fileReadWriter{f, offset})
+
+ // Writing clears privilege bits.
+ if nwritten > 0 {
+ f.attr.Perms.DropSetUIDAndMaybeGID()
+ }
+
+ return nwritten, err
}
type fileReadWriter struct {
diff --git a/pkg/sentry/fs/tmpfs/tmpfs.go b/pkg/sentry/fs/tmpfs/tmpfs.go
index 577052888..6aa8ff331 100644
--- a/pkg/sentry/fs/tmpfs/tmpfs.go
+++ b/pkg/sentry/fs/tmpfs/tmpfs.go
@@ -87,7 +87,20 @@ type Dir struct {
var _ fs.InodeOperations = (*Dir)(nil)
// NewDir returns a new directory.
-func NewDir(ctx context.Context, contents map[string]*fs.Inode, owner fs.FileOwner, perms fs.FilePermissions, msrc *fs.MountSource) *fs.Inode {
+func NewDir(ctx context.Context, contents map[string]*fs.Inode, owner fs.FileOwner, perms fs.FilePermissions, msrc *fs.MountSource, parent *fs.Inode) (*fs.Inode, error) {
+ // If the parent has setgid enabled, the new directory enables it and changes
+ // its GID.
+ if parent != nil {
+ parentUattr, err := parent.UnstableAttr(ctx)
+ if err != nil {
+ return nil, err
+ }
+ if parentUattr.Perms.SetGID {
+ owner.GID = parentUattr.Owner.GID
+ perms.SetGID = true
+ }
+ }
+
d := &Dir{
ramfsDir: ramfs.NewDir(ctx, contents, owner, perms),
kernel: kernel.KernelFromContext(ctx),
@@ -101,7 +114,7 @@ func NewDir(ctx context.Context, contents map[string]*fs.Inode, owner fs.FileOwn
InodeID: tmpfsDevice.NextIno(),
BlockSize: hostarch.PageSize,
Type: fs.Directory,
- })
+ }), nil
}
// afterLoad is invoked by stateify.
@@ -219,11 +232,21 @@ func (d *Dir) SetTimestamps(ctx context.Context, i *fs.Inode, ts fs.TimeSpec) er
func (d *Dir) newCreateOps() *ramfs.CreateOps {
return &ramfs.CreateOps{
NewDir: func(ctx context.Context, dir *fs.Inode, perms fs.FilePermissions) (*fs.Inode, error) {
- return NewDir(ctx, nil, fs.FileOwnerFromContext(ctx), perms, dir.MountSource), nil
+ return NewDir(ctx, nil, fs.FileOwnerFromContext(ctx), perms, dir.MountSource, dir)
},
NewFile: func(ctx context.Context, dir *fs.Inode, perms fs.FilePermissions) (*fs.Inode, error) {
+ // If the parent has setgid enabled, change the GID of the new file.
+ owner := fs.FileOwnerFromContext(ctx)
+ parentUattr, err := dir.UnstableAttr(ctx)
+ if err != nil {
+ return nil, err
+ }
+ if parentUattr.Perms.SetGID {
+ owner.GID = parentUattr.Owner.GID
+ }
+
uattr := fs.WithCurrentTime(ctx, fs.UnstableAttr{
- Owner: fs.FileOwnerFromContext(ctx),
+ Owner: owner,
Perms: perms,
// Always start unlinked.
Links: 0,
diff --git a/pkg/sentry/fs/user/user_test.go b/pkg/sentry/fs/user/user_test.go
index 12b786224..7f8fa8038 100644
--- a/pkg/sentry/fs/user/user_test.go
+++ b/pkg/sentry/fs/user/user_test.go
@@ -104,7 +104,10 @@ func TestGetExecUserHome(t *testing.T) {
t.Run(name, func(t *testing.T) {
ctx := contexttest.Context(t)
msrc := fs.NewPseudoMountSource(ctx)
- rootInode := tmpfs.NewDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0777), msrc)
+ rootInode, err := tmpfs.NewDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0777), msrc, nil /* parent */)
+ if err != nil {
+ t.Fatalf("tmpfs.NewDir failed: %v", err)
+ }
mns, err := fs.NewMountNamespace(ctx, rootInode)
if err != nil {
generated by cgit v1.2.3 (git 2.39.1) at 2025-03-08 03:16:06 +0000