diff options
author | gVisor bot <gvisor-bot@google.com> | 2020-02-07 22:50:34 +0000 |
---|---|---|
committer | gVisor bot <gvisor-bot@google.com> | 2020-02-07 22:50:34 +0000 |
commit | c59074e13f4238524f276b59269273e09b42ef83 (patch) | |
tree | e263d6a3e43fe67861c942d679b5c49edebf7a66 /pkg | |
parent | f254cdfc3df2b43550d3f2abac64cc06d13e3451 (diff) | |
parent | 17b9f5e66238bde1e4ed3bd9e5fb67342c8b58ec (diff) |
Merge release-20200127.0-99-g17b9f5e (automated)
Diffstat (limited to 'pkg')
-rw-r--r-- | pkg/p9/client_file.go | 33 | ||||
-rw-r--r-- | pkg/p9/file.go | 16 | ||||
-rw-r--r-- | pkg/p9/handlers.go | 33 | ||||
-rw-r--r-- | pkg/p9/messages.go | 199 | ||||
-rw-r--r-- | pkg/p9/p9.go | 4 | ||||
-rw-r--r-- | pkg/p9/version.go | 8 | ||||
-rw-r--r-- | pkg/sentry/fs/copy_up.go | 2 | ||||
-rw-r--r-- | pkg/sentry/fs/fsutil/inode.go | 20 | ||||
-rw-r--r-- | pkg/sentry/fs/gofer/context_file.go | 14 | ||||
-rw-r--r-- | pkg/sentry/fs/gofer/inode.go | 13 | ||||
-rw-r--r-- | pkg/sentry/fs/inode.go | 14 | ||||
-rw-r--r-- | pkg/sentry/fs/inode_operations.go | 13 | ||||
-rw-r--r-- | pkg/sentry/fs/inode_overlay.go | 18 | ||||
-rw-r--r-- | pkg/sentry/fs/tmpfs/tmpfs.go | 9 | ||||
-rwxr-xr-x | pkg/sentry/syscalls/linux/linux64_amd64.go | 27 | ||||
-rwxr-xr-x | pkg/sentry/syscalls/linux/linux64_arm64.go | 37 | ||||
-rwxr-xr-x | pkg/sentry/syscalls/linux/sys_xattr.go | 200 |
17 files changed, 560 insertions, 100 deletions
diff --git a/pkg/p9/client_file.go b/pkg/p9/client_file.go index 0254e4ccc..2ee07b664 100644 --- a/pkg/p9/client_file.go +++ b/pkg/p9/client_file.go @@ -194,6 +194,39 @@ func (c *clientFile) SetXattr(name, value string, flags uint32) error { return c.client.sendRecv(&Tsetxattr{FID: c.fid, Name: name, Value: value, Flags: flags}, &Rsetxattr{}) } +// ListXattr implements File.ListXattr. +func (c *clientFile) ListXattr(size uint64) (map[string]struct{}, error) { + if atomic.LoadUint32(&c.closed) != 0 { + return nil, syscall.EBADF + } + if !versionSupportsListRemoveXattr(c.client.version) { + return nil, syscall.EOPNOTSUPP + } + + rlistxattr := Rlistxattr{} + if err := c.client.sendRecv(&Tlistxattr{FID: c.fid, Size: size}, &rlistxattr); err != nil { + return nil, err + } + + xattrs := make(map[string]struct{}, len(rlistxattr.Xattrs)) + for _, x := range rlistxattr.Xattrs { + xattrs[x] = struct{}{} + } + return xattrs, nil +} + +// RemoveXattr implements File.RemoveXattr. +func (c *clientFile) RemoveXattr(name string) error { + if atomic.LoadUint32(&c.closed) != 0 { + return syscall.EBADF + } + if !versionSupportsListRemoveXattr(c.client.version) { + return syscall.EOPNOTSUPP + } + + return c.client.sendRecv(&Tremovexattr{FID: c.fid, Name: name}, &Rremovexattr{}) +} + // Allocate implements File.Allocate. func (c *clientFile) Allocate(mode AllocateMode, offset, length uint64) error { if atomic.LoadUint32(&c.closed) != 0 { diff --git a/pkg/p9/file.go b/pkg/p9/file.go index 4607cfcdf..d4ffbc8e3 100644 --- a/pkg/p9/file.go +++ b/pkg/p9/file.go @@ -105,6 +105,22 @@ type File interface { // TODO(b/127675828): Determine concurrency guarantees once implemented. SetXattr(name, value string, flags uint32) error + // ListXattr lists the names of the extended attributes on this node. + // + // Size indicates the size of the buffer that has been allocated to hold the + // attribute list. If the list would be larger than size, implementations may + // return ERANGE to indicate that the buffer is too small, but they are also + // free to ignore the hint entirely (i.e. the value returned may be larger + // than size). All size checking is done independently at the syscall layer. + // + // TODO(b/148303075): Determine concurrency guarantees once implemented. + ListXattr(size uint64) (map[string]struct{}, error) + + // RemoveXattr removes extended attributes on this node. + // + // TODO(b/148303075): Determine concurrency guarantees once implemented. + RemoveXattr(name string) error + // Allocate allows the caller to directly manipulate the allocated disk space // for the file. See fallocate(2) for more details. Allocate(mode AllocateMode, offset, length uint64) error diff --git a/pkg/p9/handlers.go b/pkg/p9/handlers.go index 7d6653a07..2ac45eb80 100644 --- a/pkg/p9/handlers.go +++ b/pkg/p9/handlers.go @@ -942,6 +942,39 @@ func (t *Tsetxattr) handle(cs *connState) message { } // handle implements handler.handle. +func (t *Tlistxattr) handle(cs *connState) message { + ref, ok := cs.LookupFID(t.FID) + if !ok { + return newErr(syscall.EBADF) + } + defer ref.DecRef() + + xattrs, err := ref.file.ListXattr(t.Size) + if err != nil { + return newErr(err) + } + xattrList := make([]string, 0, len(xattrs)) + for x := range xattrs { + xattrList = append(xattrList, x) + } + return &Rlistxattr{Xattrs: xattrList} +} + +// handle implements handler.handle. +func (t *Tremovexattr) handle(cs *connState) message { + ref, ok := cs.LookupFID(t.FID) + if !ok { + return newErr(syscall.EBADF) + } + defer ref.DecRef() + + if err := ref.file.RemoveXattr(t.Name); err != nil { + return newErr(err) + } + return &Rremovexattr{} +} + +// handle implements handler.handle. func (t *Treaddir) handle(cs *connState) message { ref, ok := cs.LookupFID(t.Directory) if !ok { diff --git a/pkg/p9/messages.go b/pkg/p9/messages.go index ceb723d86..b1cede5f5 100644 --- a/pkg/p9/messages.go +++ b/pkg/p9/messages.go @@ -174,11 +174,11 @@ type Rflush struct { } // Decode implements encoder.Decode. -func (*Rflush) Decode(b *buffer) { +func (*Rflush) Decode(*buffer) { } // Encode implements encoder.Encode. -func (*Rflush) Encode(b *buffer) { +func (*Rflush) Encode(*buffer) { } // Type implements message.Type. @@ -188,7 +188,7 @@ func (*Rflush) Type() MsgType { // String implements fmt.Stringer. func (r *Rflush) String() string { - return fmt.Sprintf("RFlush{}") + return "RFlush{}" } // Twalk is a walk request. @@ -300,11 +300,11 @@ type Rclunk struct { } // Decode implements encoder.Decode. -func (*Rclunk) Decode(b *buffer) { +func (*Rclunk) Decode(*buffer) { } // Encode implements encoder.Encode. -func (*Rclunk) Encode(b *buffer) { +func (*Rclunk) Encode(*buffer) { } // Type implements message.Type. @@ -314,7 +314,7 @@ func (*Rclunk) Type() MsgType { // String implements fmt.Stringer. func (r *Rclunk) String() string { - return fmt.Sprintf("Rclunk{}") + return "Rclunk{}" } // Tremove is a remove request. @@ -350,11 +350,11 @@ type Rremove struct { } // Decode implements encoder.Decode. -func (*Rremove) Decode(b *buffer) { +func (*Rremove) Decode(*buffer) { } // Encode implements encoder.Encode. -func (*Rremove) Encode(b *buffer) { +func (*Rremove) Encode(*buffer) { } // Type implements message.Type. @@ -364,7 +364,7 @@ func (*Rremove) Type() MsgType { // String implements fmt.Stringer. func (r *Rremove) String() string { - return fmt.Sprintf("Rremove{}") + return "Rremove{}" } // Rlerror is an error response. @@ -745,16 +745,16 @@ func (*Rlink) Type() MsgType { } // Decode implements encoder.Decode. -func (*Rlink) Decode(b *buffer) { +func (*Rlink) Decode(*buffer) { } // Encode implements encoder.Encode. -func (*Rlink) Encode(b *buffer) { +func (*Rlink) Encode(*buffer) { } // String implements fmt.Stringer. func (r *Rlink) String() string { - return fmt.Sprintf("Rlink{}") + return "Rlink{}" } // Trenameat is a rename request. @@ -803,11 +803,11 @@ type Rrenameat struct { } // Decode implements encoder.Decode. -func (*Rrenameat) Decode(b *buffer) { +func (*Rrenameat) Decode(*buffer) { } // Encode implements encoder.Encode. -func (*Rrenameat) Encode(b *buffer) { +func (*Rrenameat) Encode(*buffer) { } // Type implements message.Type. @@ -817,7 +817,7 @@ func (*Rrenameat) Type() MsgType { // String implements fmt.Stringer. func (r *Rrenameat) String() string { - return fmt.Sprintf("Rrenameat{}") + return "Rrenameat{}" } // Tunlinkat is an unlink request. @@ -861,11 +861,11 @@ type Runlinkat struct { } // Decode implements encoder.Decode. -func (*Runlinkat) Decode(b *buffer) { +func (*Runlinkat) Decode(*buffer) { } // Encode implements encoder.Encode. -func (*Runlinkat) Encode(b *buffer) { +func (*Runlinkat) Encode(*buffer) { } // Type implements message.Type. @@ -875,7 +875,7 @@ func (*Runlinkat) Type() MsgType { // String implements fmt.Stringer. func (r *Runlinkat) String() string { - return fmt.Sprintf("Runlinkat{}") + return "Runlinkat{}" } // Trename is a rename request. @@ -922,11 +922,11 @@ type Rrename struct { } // Decode implements encoder.Decode. -func (*Rrename) Decode(b *buffer) { +func (*Rrename) Decode(*buffer) { } // Encode implements encoder.Encode. -func (*Rrename) Encode(b *buffer) { +func (*Rrename) Encode(*buffer) { } // Type implements message.Type. @@ -936,7 +936,7 @@ func (*Rrename) Type() MsgType { // String implements fmt.Stringer. func (r *Rrename) String() string { - return fmt.Sprintf("Rrename{}") + return "Rrename{}" } // Treadlink is a readlink request. @@ -1409,11 +1409,11 @@ type Rsetattr struct { } // Decode implements encoder.Decode. -func (*Rsetattr) Decode(b *buffer) { +func (*Rsetattr) Decode(*buffer) { } // Encode implements encoder.Encode. -func (*Rsetattr) Encode(b *buffer) { +func (*Rsetattr) Encode(*buffer) { } // Type implements message.Type. @@ -1423,7 +1423,7 @@ func (*Rsetattr) Type() MsgType { // String implements fmt.Stringer. func (r *Rsetattr) String() string { - return fmt.Sprintf("Rsetattr{}") + return "Rsetattr{}" } // Tallocate is an allocate request. This is an extension to 9P protocol, not @@ -1466,11 +1466,11 @@ type Rallocate struct { } // Decode implements encoder.Decode. -func (*Rallocate) Decode(b *buffer) { +func (*Rallocate) Decode(*buffer) { } // Encode implements encoder.Encode. -func (*Rallocate) Encode(b *buffer) { +func (*Rallocate) Encode(*buffer) { } // Type implements message.Type. @@ -1480,7 +1480,71 @@ func (*Rallocate) Type() MsgType { // String implements fmt.Stringer. func (r *Rallocate) String() string { - return fmt.Sprintf("Rallocate{}") + return "Rallocate{}" +} + +// Tlistxattr is a listxattr request. +type Tlistxattr struct { + // FID refers to the file on which to list xattrs. + FID FID + + // Size is the buffer size for the xattr list. + Size uint64 +} + +// Decode implements encoder.Decode. +func (t *Tlistxattr) Decode(b *buffer) { + t.FID = b.ReadFID() + t.Size = b.Read64() +} + +// Encode implements encoder.Encode. +func (t *Tlistxattr) Encode(b *buffer) { + b.WriteFID(t.FID) + b.Write64(t.Size) +} + +// Type implements message.Type. +func (*Tlistxattr) Type() MsgType { + return MsgTlistxattr +} + +// String implements fmt.Stringer. +func (t *Tlistxattr) String() string { + return fmt.Sprintf("Tlistxattr{FID: %d, Size: %d}", t.FID, t.Size) +} + +// Rlistxattr is a listxattr response. +type Rlistxattr struct { + // Xattrs is a list of extended attribute names. + Xattrs []string +} + +// Decode implements encoder.Decode. +func (r *Rlistxattr) Decode(b *buffer) { + n := b.Read16() + r.Xattrs = r.Xattrs[:0] + for i := 0; i < int(n); i++ { + r.Xattrs = append(r.Xattrs, b.ReadString()) + } +} + +// Encode implements encoder.Encode. +func (r *Rlistxattr) Encode(b *buffer) { + b.Write16(uint16(len(r.Xattrs))) + for _, x := range r.Xattrs { + b.WriteString(x) + } +} + +// Type implements message.Type. +func (*Rlistxattr) Type() MsgType { + return MsgRlistxattr +} + +// String implements fmt.Stringer. +func (r *Rlistxattr) String() string { + return fmt.Sprintf("Rlistxattr{Xattrs: %v}", r.Xattrs) } // Txattrwalk walks extended attributes. @@ -1594,11 +1658,11 @@ type Rxattrcreate struct { } // Decode implements encoder.Decode. -func (r *Rxattrcreate) Decode(b *buffer) { +func (r *Rxattrcreate) Decode(*buffer) { } // Encode implements encoder.Encode. -func (r *Rxattrcreate) Encode(b *buffer) { +func (r *Rxattrcreate) Encode(*buffer) { } // Type implements message.Type. @@ -1608,7 +1672,7 @@ func (*Rxattrcreate) Type() MsgType { // String implements fmt.Stringer. func (r *Rxattrcreate) String() string { - return fmt.Sprintf("Rxattrcreate{}") + return "Rxattrcreate{}" } // Tgetxattr is a getxattr request. @@ -1719,11 +1783,11 @@ type Rsetxattr struct { } // Decode implements encoder.Decode. -func (r *Rsetxattr) Decode(b *buffer) { +func (r *Rsetxattr) Decode(*buffer) { } // Encode implements encoder.Encode. -func (r *Rsetxattr) Encode(b *buffer) { +func (r *Rsetxattr) Encode(*buffer) { } // Type implements message.Type. @@ -1733,7 +1797,60 @@ func (*Rsetxattr) Type() MsgType { // String implements fmt.Stringer. func (r *Rsetxattr) String() string { - return fmt.Sprintf("Rsetxattr{}") + return "Rsetxattr{}" +} + +// Tremovexattr is a removexattr request. +type Tremovexattr struct { + // FID refers to the file on which to set xattrs. + FID FID + + // Name is the attribute name. + Name string +} + +// Decode implements encoder.Decode. +func (t *Tremovexattr) Decode(b *buffer) { + t.FID = b.ReadFID() + t.Name = b.ReadString() +} + +// Encode implements encoder.Encode. +func (t *Tremovexattr) Encode(b *buffer) { + b.WriteFID(t.FID) + b.WriteString(t.Name) +} + +// Type implements message.Type. +func (*Tremovexattr) Type() MsgType { + return MsgTremovexattr +} + +// String implements fmt.Stringer. +func (t *Tremovexattr) String() string { + return fmt.Sprintf("Tremovexattr{FID: %d, Name: %s}", t.FID, t.Name) +} + +// Rremovexattr is a removexattr response. +type Rremovexattr struct { +} + +// Decode implements encoder.Decode. +func (r *Rremovexattr) Decode(*buffer) { +} + +// Encode implements encoder.Encode. +func (r *Rremovexattr) Encode(*buffer) { +} + +// Type implements message.Type. +func (*Rremovexattr) Type() MsgType { + return MsgRremovexattr +} + +// String implements fmt.Stringer. +func (r *Rremovexattr) String() string { + return "Rremovexattr{}" } // Treaddir is a readdir request. @@ -1880,11 +1997,11 @@ type Rfsync struct { } // Decode implements encoder.Decode. -func (*Rfsync) Decode(b *buffer) { +func (*Rfsync) Decode(*buffer) { } // Encode implements encoder.Encode. -func (*Rfsync) Encode(b *buffer) { +func (*Rfsync) Encode(*buffer) { } // Type implements message.Type. @@ -1894,7 +2011,7 @@ func (*Rfsync) Type() MsgType { // String implements fmt.Stringer. func (r *Rfsync) String() string { - return fmt.Sprintf("Rfsync{}") + return "Rfsync{}" } // Tstatfs is a stat request. @@ -1980,11 +2097,11 @@ type Rflushf struct { } // Decode implements encoder.Decode. -func (*Rflushf) Decode(b *buffer) { +func (*Rflushf) Decode(*buffer) { } // Encode implements encoder.Encode. -func (*Rflushf) Encode(b *buffer) { +func (*Rflushf) Encode(*buffer) { } // Type implements message.Type. @@ -1994,7 +2111,7 @@ func (*Rflushf) Type() MsgType { // String implements fmt.Stringer. func (*Rflushf) String() string { - return fmt.Sprintf("Rflushf{}") + return "Rflushf{}" } // Twalkgetattr is a walk request. @@ -2484,6 +2601,8 @@ func init() { msgRegistry.register(MsgRgetattr, func() message { return &Rgetattr{} }) msgRegistry.register(MsgTsetattr, func() message { return &Tsetattr{} }) msgRegistry.register(MsgRsetattr, func() message { return &Rsetattr{} }) + msgRegistry.register(MsgTlistxattr, func() message { return &Tlistxattr{} }) + msgRegistry.register(MsgRlistxattr, func() message { return &Rlistxattr{} }) msgRegistry.register(MsgTxattrwalk, func() message { return &Txattrwalk{} }) msgRegistry.register(MsgRxattrwalk, func() message { return &Rxattrwalk{} }) msgRegistry.register(MsgTxattrcreate, func() message { return &Txattrcreate{} }) @@ -2492,6 +2611,8 @@ func init() { msgRegistry.register(MsgRgetxattr, func() message { return &Rgetxattr{} }) msgRegistry.register(MsgTsetxattr, func() message { return &Tsetxattr{} }) msgRegistry.register(MsgRsetxattr, func() message { return &Rsetxattr{} }) + msgRegistry.register(MsgTremovexattr, func() message { return &Tremovexattr{} }) + msgRegistry.register(MsgRremovexattr, func() message { return &Rremovexattr{} }) msgRegistry.register(MsgTreaddir, func() message { return &Treaddir{} }) msgRegistry.register(MsgRreaddir, func() message { return &Rreaddir{} }) msgRegistry.register(MsgTfsync, func() message { return &Tfsync{} }) diff --git a/pkg/p9/p9.go b/pkg/p9/p9.go index 5ab00d625..20ab31f7a 100644 --- a/pkg/p9/p9.go +++ b/pkg/p9/p9.go @@ -335,6 +335,8 @@ const ( MsgRgetattr = 25 MsgTsetattr = 26 MsgRsetattr = 27 + MsgTlistxattr = 28 + MsgRlistxattr = 29 MsgTxattrwalk = 30 MsgRxattrwalk = 31 MsgTxattrcreate = 32 @@ -343,6 +345,8 @@ const ( MsgRgetxattr = 35 MsgTsetxattr = 36 MsgRsetxattr = 37 + MsgTremovexattr = 38 + MsgRremovexattr = 39 MsgTreaddir = 40 MsgRreaddir = 41 MsgTfsync = 50 diff --git a/pkg/p9/version.go b/pkg/p9/version.go index 34a15eb55..09cde9f5a 100644 --- a/pkg/p9/version.go +++ b/pkg/p9/version.go @@ -26,7 +26,7 @@ const ( // // Clients are expected to start requesting this version number and // to continuously decrement it until a Tversion request succeeds. - highestSupportedVersion uint32 = 10 + highestSupportedVersion uint32 = 11 // lowestSupportedVersion is the lowest supported version X in a // version string of the format 9P2000.L.Google.X. @@ -167,3 +167,9 @@ func VersionSupportsOpenTruncateFlag(v uint32) bool { func versionSupportsGetSetXattr(v uint32) bool { return v >= 10 } + +// versionSupportsListRemoveXattr returns true if version v supports +// the Tlistxattr and Tremovexattr messages. +func versionSupportsListRemoveXattr(v uint32) bool { + return v >= 11 +} diff --git a/pkg/sentry/fs/copy_up.go b/pkg/sentry/fs/copy_up.go index f6c79e51b..b060a12ff 100644 --- a/pkg/sentry/fs/copy_up.go +++ b/pkg/sentry/fs/copy_up.go @@ -401,7 +401,7 @@ func copyAttributesLocked(ctx context.Context, upper *Inode, lower *Inode) error if err != nil { return err } - lowerXattr, err := lower.ListXattr(ctx) + lowerXattr, err := lower.ListXattr(ctx, linux.XATTR_SIZE_MAX) if err != nil && err != syserror.EOPNOTSUPP { return err } diff --git a/pkg/sentry/fs/fsutil/inode.go b/pkg/sentry/fs/fsutil/inode.go index 252830572..daecc4ffe 100644 --- a/pkg/sentry/fs/fsutil/inode.go +++ b/pkg/sentry/fs/fsutil/inode.go @@ -247,7 +247,7 @@ func (i *InodeSimpleExtendedAttributes) SetXattr(_ context.Context, _ *fs.Inode, } // ListXattr implements fs.InodeOperations.ListXattr. -func (i *InodeSimpleExtendedAttributes) ListXattr(context.Context, *fs.Inode) (map[string]struct{}, error) { +func (i *InodeSimpleExtendedAttributes) ListXattr(context.Context, *fs.Inode, uint64) (map[string]struct{}, error) { i.mu.RLock() names := make(map[string]struct{}, len(i.xattrs)) for name := range i.xattrs { @@ -257,6 +257,17 @@ func (i *InodeSimpleExtendedAttributes) ListXattr(context.Context, *fs.Inode) (m return names, nil } +// RemoveXattr implements fs.InodeOperations.RemoveXattr. +func (i *InodeSimpleExtendedAttributes) RemoveXattr(_ context.Context, _ *fs.Inode, name string) error { + i.mu.RLock() + defer i.mu.RUnlock() + if _, ok := i.xattrs[name]; ok { + delete(i.xattrs, name) + return nil + } + return syserror.ENOATTR +} + // staticFile is a file with static contents. It is returned by // InodeStaticFileGetter.GetFile. // @@ -460,10 +471,15 @@ func (InodeNoExtendedAttributes) SetXattr(context.Context, *fs.Inode, string, st } // ListXattr implements fs.InodeOperations.ListXattr. -func (InodeNoExtendedAttributes) ListXattr(context.Context, *fs.Inode) (map[string]struct{}, error) { +func (InodeNoExtendedAttributes) ListXattr(context.Context, *fs.Inode, uint64) (map[string]struct{}, error) { return nil, syserror.EOPNOTSUPP } +// RemoveXattr implements fs.InodeOperations.RemoveXattr. +func (InodeNoExtendedAttributes) RemoveXattr(context.Context, *fs.Inode, string) error { + return syserror.EOPNOTSUPP +} + // InodeNoopRelease implements fs.InodeOperations.Release as a noop. type InodeNoopRelease struct{} diff --git a/pkg/sentry/fs/gofer/context_file.go b/pkg/sentry/fs/gofer/context_file.go index 3da818aed..125907d70 100644 --- a/pkg/sentry/fs/gofer/context_file.go +++ b/pkg/sentry/fs/gofer/context_file.go @@ -73,6 +73,20 @@ func (c *contextFile) setXattr(ctx context.Context, name, value string, flags ui return err } +func (c *contextFile) listXattr(ctx context.Context, size uint64) (map[string]struct{}, error) { + ctx.UninterruptibleSleepStart(false) + xattrs, err := c.file.ListXattr(size) + ctx.UninterruptibleSleepFinish(false) + return xattrs, err +} + +func (c *contextFile) removeXattr(ctx context.Context, name string) error { + ctx.UninterruptibleSleepStart(false) + err := c.file.RemoveXattr(name) + ctx.UninterruptibleSleepFinish(false) + return err +} + func (c *contextFile) allocate(ctx context.Context, mode p9.AllocateMode, offset, length uint64) error { ctx.UninterruptibleSleepStart(false) err := c.file.Allocate(mode, offset, length) diff --git a/pkg/sentry/fs/gofer/inode.go b/pkg/sentry/fs/gofer/inode.go index ac28174d2..1c934981b 100644 --- a/pkg/sentry/fs/gofer/inode.go +++ b/pkg/sentry/fs/gofer/inode.go @@ -604,18 +604,23 @@ func (i *inodeOperations) Truncate(ctx context.Context, inode *fs.Inode, length } // GetXattr implements fs.InodeOperations.GetXattr. -func (i *inodeOperations) GetXattr(ctx context.Context, inode *fs.Inode, name string, size uint64) (string, error) { +func (i *inodeOperations) GetXattr(ctx context.Context, _ *fs.Inode, name string, size uint64) (string, error) { return i.fileState.file.getXattr(ctx, name, size) } // SetXattr implements fs.InodeOperations.SetXattr. -func (i *inodeOperations) SetXattr(ctx context.Context, inode *fs.Inode, name string, value string, flags uint32) error { +func (i *inodeOperations) SetXattr(ctx context.Context, _ *fs.Inode, name string, value string, flags uint32) error { return i.fileState.file.setXattr(ctx, name, value, flags) } // ListXattr implements fs.InodeOperations.ListXattr. -func (i *inodeOperations) ListXattr(context.Context, *fs.Inode) (map[string]struct{}, error) { - return nil, syscall.EOPNOTSUPP +func (i *inodeOperations) ListXattr(ctx context.Context, _ *fs.Inode, size uint64) (map[string]struct{}, error) { + return i.fileState.file.listXattr(ctx, size) +} + +// RemoveXattr implements fs.InodeOperations.RemoveXattr. +func (i *inodeOperations) RemoveXattr(ctx context.Context, _ *fs.Inode, name string) error { + return i.fileState.file.removeXattr(ctx, name) } // Allocate implements fs.InodeOperations.Allocate. diff --git a/pkg/sentry/fs/inode.go b/pkg/sentry/fs/inode.go index b66c091ab..55fb71c16 100644 --- a/pkg/sentry/fs/inode.go +++ b/pkg/sentry/fs/inode.go @@ -278,11 +278,19 @@ func (i *Inode) SetXattr(ctx context.Context, d *Dirent, name, value string, fla } // ListXattr calls i.InodeOperations.ListXattr with i as the Inode. -func (i *Inode) ListXattr(ctx context.Context) (map[string]struct{}, error) { +func (i *Inode) ListXattr(ctx context.Context, size uint64) (map[string]struct{}, error) { if i.overlay != nil { - return overlayListXattr(ctx, i.overlay) + return overlayListXattr(ctx, i.overlay, size) } - return i.InodeOperations.ListXattr(ctx, i) + return i.InodeOperations.ListXattr(ctx, i, size) +} + +// RemoveXattr calls i.InodeOperations.RemoveXattr with i as the Inode. +func (i *Inode) RemoveXattr(ctx context.Context, d *Dirent, name string) error { + if i.overlay != nil { + return overlayRemoveXattr(ctx, i.overlay, d, name) + } + return i.InodeOperations.RemoveXattr(ctx, i, name) } // CheckPermission will check if the caller may access this file in the diff --git a/pkg/sentry/fs/inode_operations.go b/pkg/sentry/fs/inode_operations.go index 70f2eae96..2bbfb72ef 100644 --- a/pkg/sentry/fs/inode_operations.go +++ b/pkg/sentry/fs/inode_operations.go @@ -190,7 +190,18 @@ type InodeOperations interface { // ListXattr returns the set of all extended attributes names that // have values. Inodes that do not support extended attributes return // EOPNOTSUPP. - ListXattr(ctx context.Context, inode *Inode) (map[string]struct{}, error) + // + // If this is called through the listxattr(2) syscall, size indicates the + // size of the buffer that the application has allocated to hold the + // attribute list. If the list would be larger than size, implementations may + // return ERANGE to indicate that the buffer is too small, but they are also + // free to ignore the hint entirely. All size checking is done independently + // at the syscall layer. + ListXattr(ctx context.Context, inode *Inode, size uint64) (map[string]struct{}, error) + + // RemoveXattr removes an extended attribute specified by name. Inodes that + // do not support extended attributes return EOPNOTSUPP. + RemoveXattr(ctx context.Context, inode *Inode, name string) error // Check determines whether an Inode can be accessed with the // requested permission mask using the context (which gives access diff --git a/pkg/sentry/fs/inode_overlay.go b/pkg/sentry/fs/inode_overlay.go index 4729b4aac..5ada33a32 100644 --- a/pkg/sentry/fs/inode_overlay.go +++ b/pkg/sentry/fs/inode_overlay.go @@ -564,15 +564,15 @@ func overlaySetxattr(ctx context.Context, o *overlayEntry, d *Dirent, name, valu return o.upper.SetXattr(ctx, d, name, value, flags) } -func overlayListXattr(ctx context.Context, o *overlayEntry) (map[string]struct{}, error) { +func overlayListXattr(ctx context.Context, o *overlayEntry, size uint64) (map[string]struct{}, error) { o.copyMu.RLock() defer o.copyMu.RUnlock() var names map[string]struct{} var err error if o.upper != nil { - names, err = o.upper.ListXattr(ctx) + names, err = o.upper.ListXattr(ctx, size) } else { - names, err = o.lower.ListXattr(ctx) + names, err = o.lower.ListXattr(ctx, size) } for name := range names { // Same as overlayGetXattr, we shouldn't forward along @@ -584,6 +584,18 @@ func overlayListXattr(ctx context.Context, o *overlayEntry) (map[string]struct{} return names, err } +func overlayRemoveXattr(ctx context.Context, o *overlayEntry, d *Dirent, name string) error { + // Don't allow changes to overlay xattrs through a removexattr syscall. + if strings.HasPrefix(XattrOverlayPrefix, name) { + return syserror.EPERM + } + + if err := copyUp(ctx, d); err != nil { + return err + } + return o.upper.RemoveXattr(ctx, d, name) +} + func overlayCheck(ctx context.Context, o *overlayEntry, p PermMask) error { o.copyMu.RLock() // Hot path. Avoid defers. diff --git a/pkg/sentry/fs/tmpfs/tmpfs.go b/pkg/sentry/fs/tmpfs/tmpfs.go index c00cef0a5..3c2b583ae 100644 --- a/pkg/sentry/fs/tmpfs/tmpfs.go +++ b/pkg/sentry/fs/tmpfs/tmpfs.go @@ -159,8 +159,13 @@ func (d *Dir) SetXattr(ctx context.Context, i *fs.Inode, name, value string, fla } // ListXattr implements fs.InodeOperations.ListXattr. -func (d *Dir) ListXattr(ctx context.Context, i *fs.Inode) (map[string]struct{}, error) { - return d.ramfsDir.ListXattr(ctx, i) +func (d *Dir) ListXattr(ctx context.Context, i *fs.Inode, size uint64) (map[string]struct{}, error) { + return d.ramfsDir.ListXattr(ctx, i, size) +} + +// RemoveXattr implements fs.InodeOperations.RemoveXattr. +func (d *Dir) RemoveXattr(ctx context.Context, i *fs.Inode, name string) error { + return d.ramfsDir.RemoveXattr(ctx, i, name) } // Lookup implements fs.InodeOperations.Lookup. diff --git a/pkg/sentry/syscalls/linux/linux64_amd64.go b/pkg/sentry/syscalls/linux/linux64_amd64.go index 588f8b087..79066ad2a 100755 --- a/pkg/sentry/syscalls/linux/linux64_amd64.go +++ b/pkg/sentry/syscalls/linux/linux64_amd64.go @@ -228,21 +228,18 @@ var AMD64 = &kernel.SyscallTable{ 185: syscalls.Error("security", syserror.ENOSYS, "Not implemented in Linux.", nil), 186: syscalls.Supported("gettid", Gettid), 187: syscalls.Supported("readahead", Readahead), - // TODO(b/148303075): Enable set/getxattr (in their various - // forms) once we also have list and removexattr. The JVM - // assumes that if get/set exist, then list and remove do too. - 188: syscalls.ErrorWithEvent("setxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 189: syscalls.ErrorWithEvent("lsetxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 190: syscalls.ErrorWithEvent("fsetxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 191: syscalls.ErrorWithEvent("getxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 192: syscalls.ErrorWithEvent("lgetxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 193: syscalls.ErrorWithEvent("fgetxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 194: syscalls.ErrorWithEvent("listxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 195: syscalls.ErrorWithEvent("llistxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 196: syscalls.ErrorWithEvent("flistxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 197: syscalls.ErrorWithEvent("removexattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 198: syscalls.ErrorWithEvent("lremovexattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 199: syscalls.ErrorWithEvent("fremovexattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), + 188: syscalls.PartiallySupported("setxattr", SetXattr, "Only supported for tmpfs.", nil), + 189: syscalls.PartiallySupported("lsetxattr", LSetXattr, "Only supported for tmpfs.", nil), + 190: syscalls.PartiallySupported("fsetxattr", FSetXattr, "Only supported for tmpfs.", nil), + 191: syscalls.PartiallySupported("getxattr", GetXattr, "Only supported for tmpfs.", nil), + 192: syscalls.PartiallySupported("lgetxattr", LGetXattr, "Only supported for tmpfs.", nil), + 193: syscalls.PartiallySupported("fgetxattr", FGetXattr, "Only supported for tmpfs.", nil), + 194: syscalls.PartiallySupported("listxattr", ListXattr, "Only supported for tmpfs", nil), + 195: syscalls.PartiallySupported("llistxattr", LListXattr, "Only supported for tmpfs", nil), + 196: syscalls.PartiallySupported("flistxattr", FListXattr, "Only supported for tmpfs", nil), + 197: syscalls.PartiallySupported("removexattr", RemoveXattr, "Only supported for tmpfs", nil), + 198: syscalls.PartiallySupported("lremovexattr", LRemoveXattr, "Only supported for tmpfs", nil), + 199: syscalls.PartiallySupported("fremovexattr", FRemoveXattr, "Only supported for tmpfs", nil), 200: syscalls.Supported("tkill", Tkill), 201: syscalls.Supported("time", Time), 202: syscalls.PartiallySupported("futex", Futex, "Robust futexes not supported.", nil), diff --git a/pkg/sentry/syscalls/linux/linux64_arm64.go b/pkg/sentry/syscalls/linux/linux64_arm64.go index 06e5ee401..7421619de 100755 --- a/pkg/sentry/syscalls/linux/linux64_arm64.go +++ b/pkg/sentry/syscalls/linux/linux64_arm64.go @@ -36,26 +36,23 @@ var ARM64 = &kernel.SyscallTable{ }, AuditNumber: linux.AUDIT_ARCH_AARCH64, Table: map[uintptr]kernel.Syscall{ - 0: syscalls.PartiallySupported("io_setup", IoSetup, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}), - 1: syscalls.PartiallySupported("io_destroy", IoDestroy, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}), - 2: syscalls.PartiallySupported("io_submit", IoSubmit, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}), - 3: syscalls.PartiallySupported("io_cancel", IoCancel, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}), - 4: syscalls.PartiallySupported("io_getevents", IoGetevents, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}), - // TODO(b/148303075): Enable set/getxattr (in their various - // forms) once we also have list and removexattr. The JVM - // assumes that if get/set exist, then list and remove do too. - 5: syscalls.ErrorWithEvent("setxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 6: syscalls.ErrorWithEvent("lsetxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 7: syscalls.ErrorWithEvent("fsetxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 8: syscalls.ErrorWithEvent("getxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 9: syscalls.ErrorWithEvent("lgetxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 10: syscalls.ErrorWithEvent("fgetxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 11: syscalls.ErrorWithEvent("listxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 13: syscalls.ErrorWithEvent("llistxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 13: syscalls.ErrorWithEvent("flistxattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 14: syscalls.ErrorWithEvent("removexattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 15: syscalls.ErrorWithEvent("lremovexattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), - 16: syscalls.ErrorWithEvent("fremovexattr", syserror.ENOTSUP, "Requires filesystem support.", []string{"gvisor.dev/issue/1636"}), + 0: syscalls.PartiallySupported("io_setup", IoSetup, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}), + 1: syscalls.PartiallySupported("io_destroy", IoDestroy, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}), + 2: syscalls.PartiallySupported("io_submit", IoSubmit, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}), + 3: syscalls.PartiallySupported("io_cancel", IoCancel, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}), + 4: syscalls.PartiallySupported("io_getevents", IoGetevents, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}), + 5: syscalls.PartiallySupported("setxattr", SetXattr, "Only supported for tmpfs.", nil), + 6: syscalls.PartiallySupported("lsetxattr", LSetXattr, "Only supported for tmpfs.", nil), + 7: syscalls.PartiallySupported("fsetxattr", FSetXattr, "Only supported for tmpfs.", nil), + 8: syscalls.PartiallySupported("getxattr", GetXattr, "Only supported for tmpfs.", nil), + 9: syscalls.PartiallySupported("lgetxattr", LGetXattr, "Only supported for tmpfs.", nil), + 10: syscalls.PartiallySupported("fgetxattr", FGetXattr, "Only supported for tmpfs.", nil), + 11: syscalls.PartiallySupported("listxattr", ListXattr, "Only supported for tmpfs", nil), + 12: syscalls.PartiallySupported("llistxattr", LListXattr, "Only supported for tmpfs", nil), + 13: syscalls.PartiallySupported("flistxattr", FListXattr, "Only supported for tmpfs", nil), + 14: syscalls.PartiallySupported("removexattr", RemoveXattr, "Only supported for tmpfs", nil), + 15: syscalls.PartiallySupported("lremovexattr", LRemoveXattr, "Only supported for tmpfs", nil), + 16: syscalls.PartiallySupported("fremovexattr", FRemoveXattr, "Only supported for tmpfs", nil), 17: syscalls.Supported("getcwd", Getcwd), 18: syscalls.CapError("lookup_dcookie", linux.CAP_SYS_ADMIN, "", nil), 19: syscalls.Supported("eventfd2", Eventfd2), diff --git a/pkg/sentry/syscalls/linux/sys_xattr.go b/pkg/sentry/syscalls/linux/sys_xattr.go index efb95555c..342337726 100755 --- a/pkg/sentry/syscalls/linux/sys_xattr.go +++ b/pkg/sentry/syscalls/linux/sys_xattr.go @@ -72,7 +72,7 @@ func getXattrFromPath(t *kernel.Task, args arch.SyscallArguments, resolveSymlink } valueLen := 0 - err = fileOpOn(t, linux.AT_FDCWD, path, resolveSymlink, func(root *fs.Dirent, d *fs.Dirent, _ uint) error { + err = fileOpOn(t, linux.AT_FDCWD, path, resolveSymlink, func(_ *fs.Dirent, d *fs.Dirent, _ uint) error { if dirPath && !fs.IsDir(d.Inode.StableAttr) { return syserror.ENOTDIR } @@ -172,7 +172,7 @@ func setXattrFromPath(t *kernel.Task, args arch.SyscallArguments, resolveSymlink return 0, nil, err } - return 0, nil, fileOpOn(t, linux.AT_FDCWD, path, resolveSymlink, func(root *fs.Dirent, d *fs.Dirent, _ uint) error { + return 0, nil, fileOpOn(t, linux.AT_FDCWD, path, resolveSymlink, func(_ *fs.Dirent, d *fs.Dirent, _ uint) error { if dirPath && !fs.IsDir(d.Inode.StableAttr) { return syserror.ENOTDIR } @@ -187,12 +187,12 @@ func setXattr(t *kernel.Task, d *fs.Dirent, nameAddr, valueAddr usermem.Addr, si return syserror.EINVAL } - if err := checkXattrPermissions(t, d.Inode, fs.PermMask{Write: true}); err != nil { + name, err := copyInXattrName(t, nameAddr) + if err != nil { return err } - name, err := copyInXattrName(t, nameAddr) - if err != nil { + if err := checkXattrPermissions(t, d.Inode, fs.PermMask{Write: true}); err != nil { return err } @@ -226,12 +226,18 @@ func copyInXattrName(t *kernel.Task, nameAddr usermem.Addr) (string, error) { return name, nil } +// Restrict xattrs to regular files and directories. +// +// TODO(b/148380782): In Linux, this restriction technically only applies to +// xattrs in the "user.*" namespace. Make file type checks specific to the +// namespace once we allow other xattr prefixes. +func xattrFileTypeOk(i *fs.Inode) bool { + return fs.IsRegular(i.StableAttr) || fs.IsDir(i.StableAttr) +} + func checkXattrPermissions(t *kernel.Task, i *fs.Inode, perms fs.PermMask) error { // Restrict xattrs to regular files and directories. - // - // In Linux, this restriction technically only applies to xattrs in the - // "user.*" namespace, but we don't allow any other xattr prefixes anyway. - if !fs.IsRegular(i.StableAttr) && !fs.IsDir(i.StableAttr) { + if !xattrFileTypeOk(i) { if perms.Write { return syserror.EPERM } @@ -240,3 +246,179 @@ func checkXattrPermissions(t *kernel.Task, i *fs.Inode, perms fs.PermMask) error return i.CheckPermission(t, perms) } + +// ListXattr implements linux syscall listxattr(2). +func ListXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { + return listXattrFromPath(t, args, true) +} + +// LListXattr implements linux syscall llistxattr(2). +func LListXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { + return listXattrFromPath(t, args, false) +} + +// FListXattr implements linux syscall flistxattr(2). +func FListXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { + fd := args[0].Int() + listAddr := args[1].Pointer() + size := uint64(args[2].SizeT()) + + // TODO(b/113957122): Return EBADF if the fd was opened with O_PATH. + f := t.GetFile(fd) + if f == nil { + return 0, nil, syserror.EBADF + } + defer f.DecRef() + + n, err := listXattr(t, f.Dirent, listAddr, size) + if err != nil { + return 0, nil, err + } + + return uintptr(n), nil, nil +} + +func listXattrFromPath(t *kernel.Task, args arch.SyscallArguments, resolveSymlink bool) (uintptr, *kernel.SyscallControl, error) { + pathAddr := args[0].Pointer() + listAddr := args[1].Pointer() + size := uint64(args[2].SizeT()) + + path, dirPath, err := copyInPath(t, pathAddr, false /* allowEmpty */) + if err != nil { + return 0, nil, err + } + + n := 0 + err = fileOpOn(t, linux.AT_FDCWD, path, resolveSymlink, func(_ *fs.Dirent, d *fs.Dirent, _ uint) error { + if dirPath && !fs.IsDir(d.Inode.StableAttr) { + return syserror.ENOTDIR + } + + n, err = listXattr(t, d, listAddr, size) + return err + }) + if err != nil { + return 0, nil, err + } + + return uintptr(n), nil, nil +} + +func listXattr(t *kernel.Task, d *fs.Dirent, addr usermem.Addr, size uint64) (int, error) { + if !xattrFileTypeOk(d.Inode) { + return 0, nil + } + + // If listxattr(2) is called with size 0, the buffer size needed to contain + // the xattr list will be returned successfully even if it is nonzero. In + // that case, we need to retrieve the entire list so we can compute and + // return the correct size. + requestedSize := size + if size == 0 || size > linux.XATTR_SIZE_MAX { + requestedSize = linux.XATTR_SIZE_MAX + } + xattrs, err := d.Inode.ListXattr(t, requestedSize) + if err != nil { + return 0, err + } + + // TODO(b/148380782): support namespaces other than "user". + for x := range xattrs { + if !strings.HasPrefix(x, linux.XATTR_USER_PREFIX) { + delete(xattrs, x) + } + } + + listSize := xattrListSize(xattrs) + if listSize > linux.XATTR_SIZE_MAX { + return 0, syserror.E2BIG + } + if uint64(listSize) > requestedSize { + return 0, syserror.ERANGE + } + + // Don't copy out the attributes if size is 0. + if size == 0 { + return listSize, nil + } + + buf := make([]byte, 0, listSize) + for x := range xattrs { + buf = append(buf, []byte(x)...) + buf = append(buf, 0) + } + if _, err := t.CopyOutBytes(addr, buf); err != nil { + return 0, err + } + + return len(buf), nil +} + +func xattrListSize(xattrs map[string]struct{}) int { + size := 0 + for x := range xattrs { + size += len(x) + 1 + } + return size +} + +// RemoveXattr implements linux syscall removexattr(2). +func RemoveXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { + return removeXattrFromPath(t, args, true) +} + +// LRemoveXattr implements linux syscall lremovexattr(2). +func LRemoveXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { + return removeXattrFromPath(t, args, false) +} + +// FRemoveXattr implements linux syscall fremovexattr(2). +func FRemoveXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { + fd := args[0].Int() + nameAddr := args[1].Pointer() + + // TODO(b/113957122): Return EBADF if the fd was opened with O_PATH. + f := t.GetFile(fd) + if f == nil { + return 0, nil, syserror.EBADF + } + defer f.DecRef() + + return 0, nil, removeXattr(t, f.Dirent, nameAddr) +} + +func removeXattrFromPath(t *kernel.Task, args arch.SyscallArguments, resolveSymlink bool) (uintptr, *kernel.SyscallControl, error) { + pathAddr := args[0].Pointer() + nameAddr := args[1].Pointer() + + path, dirPath, err := copyInPath(t, pathAddr, false /* allowEmpty */) + if err != nil { + return 0, nil, err + } + + return 0, nil, fileOpOn(t, linux.AT_FDCWD, path, resolveSymlink, func(_ *fs.Dirent, d *fs.Dirent, _ uint) error { + if dirPath && !fs.IsDir(d.Inode.StableAttr) { + return syserror.ENOTDIR + } + + return removeXattr(t, d, nameAddr) + }) +} + +// removeXattr implements removexattr(2) from the given *fs.Dirent. +func removeXattr(t *kernel.Task, d *fs.Dirent, nameAddr usermem.Addr) error { + name, err := copyInXattrName(t, nameAddr) + if err != nil { + return err + } + + if err := checkXattrPermissions(t, d.Inode, fs.PermMask{Write: true}); err != nil { + return err + } + + if !strings.HasPrefix(name, linux.XATTR_USER_PREFIX) { + return syserror.EOPNOTSUPP + } + + return d.Inode.RemoveXattr(t, d, name) +} |