diff options
Diffstat (limited to 'pkg/sentry')
-rw-r--r-- | pkg/sentry/fs/copy_up.go | 9 | ||||
-rw-r--r-- | pkg/sentry/fs/file_overlay.go | 2 | ||||
-rw-r--r-- | pkg/sentry/fs/fsutil/inode.go | 41 | ||||
-rw-r--r-- | pkg/sentry/fs/gofer/context_file.go | 14 | ||||
-rw-r--r-- | pkg/sentry/fs/gofer/inode.go | 18 | ||||
-rw-r--r-- | pkg/sentry/fs/inode.go | 24 | ||||
-rw-r--r-- | pkg/sentry/fs/inode_operations.go | 25 | ||||
-rw-r--r-- | pkg/sentry/fs/inode_overlay.go | 30 | ||||
-rw-r--r-- | pkg/sentry/fs/inode_overlay_test.go | 4 | ||||
-rw-r--r-- | pkg/sentry/fs/tmpfs/tmpfs.go | 18 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/linux64_amd64.go | 4 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/linux64_arm64.go | 4 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/sys_xattr.go | 48 |
13 files changed, 148 insertions, 93 deletions
diff --git a/pkg/sentry/fs/copy_up.go b/pkg/sentry/fs/copy_up.go index 734177e90..e03e3e417 100644 --- a/pkg/sentry/fs/copy_up.go +++ b/pkg/sentry/fs/copy_up.go @@ -18,6 +18,7 @@ import ( "fmt" "io" + "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/sentry/context" "gvisor.dev/gvisor/pkg/sentry/memmap" @@ -395,12 +396,12 @@ func copyContentsLocked(ctx context.Context, upper *Inode, lower *Inode, size in // Size and permissions are set on upper when the file content is copied // and when the file is created respectively. func copyAttributesLocked(ctx context.Context, upper *Inode, lower *Inode) error { - // Extract attributes fro the lower filesystem. + // Extract attributes from the lower filesystem. lowerAttr, err := lower.UnstableAttr(ctx) if err != nil { return err } - lowerXattr, err := lower.Listxattr() + lowerXattr, err := lower.ListXattr(ctx) if err != nil && err != syserror.EOPNOTSUPP { return err } @@ -421,11 +422,11 @@ func copyAttributesLocked(ctx context.Context, upper *Inode, lower *Inode) error if isXattrOverlay(name) { continue } - value, err := lower.Getxattr(name) + value, err := lower.GetXattr(ctx, name, linux.XATTR_SIZE_MAX) if err != nil { return err } - if err := upper.InodeOperations.Setxattr(upper, name, value); err != nil { + if err := upper.InodeOperations.SetXattr(ctx, upper, name, value, 0 /* flags */); err != nil { return err } } diff --git a/pkg/sentry/fs/file_overlay.go b/pkg/sentry/fs/file_overlay.go index 8a633b1ba..8991207b4 100644 --- a/pkg/sentry/fs/file_overlay.go +++ b/pkg/sentry/fs/file_overlay.go @@ -475,7 +475,7 @@ func readdirEntries(ctx context.Context, o *overlayEntry) (*SortedDentryMap, err // Skip this name if it is a negative entry in the // upper or there exists a whiteout for it. if o.upper != nil { - if overlayHasWhiteout(o.upper, name) { + if overlayHasWhiteout(ctx, o.upper, name) { continue } } diff --git a/pkg/sentry/fs/fsutil/inode.go b/pkg/sentry/fs/fsutil/inode.go index adf5ec69c..df7b74855 100644 --- a/pkg/sentry/fs/fsutil/inode.go +++ b/pkg/sentry/fs/fsutil/inode.go @@ -15,6 +15,7 @@ package fsutil import ( + "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/sentry/context" "gvisor.dev/gvisor/pkg/sentry/fs" ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time" @@ -202,7 +203,7 @@ func (i *InodeSimpleAttributes) NotifyModificationAndStatusChange(ctx context.Co } // InodeSimpleExtendedAttributes implements -// fs.InodeOperations.{Get,Set,List}xattr. +// fs.InodeOperations.{Get,Set,List}Xattr. // // +stateify savable type InodeSimpleExtendedAttributes struct { @@ -211,8 +212,8 @@ type InodeSimpleExtendedAttributes struct { xattrs map[string]string } -// Getxattr implements fs.InodeOperations.Getxattr. -func (i *InodeSimpleExtendedAttributes) Getxattr(_ *fs.Inode, name string) (string, error) { +// GetXattr implements fs.InodeOperations.GetXattr. +func (i *InodeSimpleExtendedAttributes) GetXattr(_ context.Context, _ *fs.Inode, name string, _ uint64) (string, error) { i.mu.RLock() value, ok := i.xattrs[name] i.mu.RUnlock() @@ -222,19 +223,31 @@ func (i *InodeSimpleExtendedAttributes) Getxattr(_ *fs.Inode, name string) (stri return value, nil } -// Setxattr implements fs.InodeOperations.Setxattr. -func (i *InodeSimpleExtendedAttributes) Setxattr(_ *fs.Inode, name, value string) error { +// SetXattr implements fs.InodeOperations.SetXattr. +func (i *InodeSimpleExtendedAttributes) SetXattr(_ context.Context, _ *fs.Inode, name, value string, flags uint32) error { i.mu.Lock() + defer i.mu.Unlock() if i.xattrs == nil { + if flags&linux.XATTR_REPLACE != 0 { + return syserror.ENODATA + } i.xattrs = make(map[string]string) } + + _, ok := i.xattrs[name] + if ok && flags&linux.XATTR_CREATE != 0 { + return syserror.EEXIST + } + if !ok && flags&linux.XATTR_REPLACE != 0 { + return syserror.ENODATA + } + i.xattrs[name] = value - i.mu.Unlock() return nil } -// Listxattr implements fs.InodeOperations.Listxattr. -func (i *InodeSimpleExtendedAttributes) Listxattr(_ *fs.Inode) (map[string]struct{}, error) { +// ListXattr implements fs.InodeOperations.ListXattr. +func (i *InodeSimpleExtendedAttributes) ListXattr(context.Context, *fs.Inode) (map[string]struct{}, error) { i.mu.RLock() names := make(map[string]struct{}, len(i.xattrs)) for name := range i.xattrs { @@ -436,18 +449,18 @@ func (InodeNotSymlink) Getlink(context.Context, *fs.Inode) (*fs.Dirent, error) { // extended attributes. type InodeNoExtendedAttributes struct{} -// Getxattr implements fs.InodeOperations.Getxattr. -func (InodeNoExtendedAttributes) Getxattr(*fs.Inode, string) (string, error) { +// GetXattr implements fs.InodeOperations.GetXattr. +func (InodeNoExtendedAttributes) GetXattr(context.Context, *fs.Inode, string, uint64) (string, error) { return "", syserror.EOPNOTSUPP } -// Setxattr implements fs.InodeOperations.Setxattr. -func (InodeNoExtendedAttributes) Setxattr(*fs.Inode, string, string) error { +// SetXattr implements fs.InodeOperations.SetXattr. +func (InodeNoExtendedAttributes) SetXattr(context.Context, *fs.Inode, string, string, uint32) error { return syserror.EOPNOTSUPP } -// Listxattr implements fs.InodeOperations.Listxattr. -func (InodeNoExtendedAttributes) Listxattr(*fs.Inode) (map[string]struct{}, error) { +// ListXattr implements fs.InodeOperations.ListXattr. +func (InodeNoExtendedAttributes) ListXattr(context.Context, *fs.Inode) (map[string]struct{}, error) { return nil, syserror.EOPNOTSUPP } diff --git a/pkg/sentry/fs/gofer/context_file.go b/pkg/sentry/fs/gofer/context_file.go index 44b72582a..2125dafef 100644 --- a/pkg/sentry/fs/gofer/context_file.go +++ b/pkg/sentry/fs/gofer/context_file.go @@ -59,6 +59,20 @@ func (c *contextFile) setAttr(ctx context.Context, valid p9.SetAttrMask, attr p9 return err } +func (c *contextFile) getXattr(ctx context.Context, name string, size uint64) (string, error) { + ctx.UninterruptibleSleepStart(false) + val, err := c.file.GetXattr(name, size) + ctx.UninterruptibleSleepFinish(false) + return val, err +} + +func (c *contextFile) setXattr(ctx context.Context, name, value string, flags uint32) error { + ctx.UninterruptibleSleepStart(false) + err := c.file.SetXattr(name, value, flags) + 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 245fe2ef1..98d1a8a48 100644 --- a/pkg/sentry/fs/gofer/inode.go +++ b/pkg/sentry/fs/gofer/inode.go @@ -38,8 +38,7 @@ import ( // // +stateify savable type inodeOperations struct { - fsutil.InodeNotVirtual `state:"nosave"` - fsutil.InodeNoExtendedAttributes `state:"nosave"` + fsutil.InodeNotVirtual `state:"nosave"` // fileState implements fs.CachedFileObject. It exists // to break a circular load dependency between inodeOperations @@ -604,6 +603,21 @@ func (i *inodeOperations) Truncate(ctx context.Context, inode *fs.Inode, length return i.fileState.file.setAttr(ctx, p9.SetAttrMask{Size: true}, p9.SetAttr{Size: uint64(length)}) } +// GetXattr implements fs.InodeOperations.GetXattr. +func (i *inodeOperations) GetXattr(ctx context.Context, inode *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 { + 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 +} + // Allocate implements fs.InodeOperations.Allocate. func (i *inodeOperations) Allocate(ctx context.Context, inode *fs.Inode, offset, length int64) error { // This can only be called for files anyway. diff --git a/pkg/sentry/fs/inode.go b/pkg/sentry/fs/inode.go index 468043df0..ee9d301ef 100644 --- a/pkg/sentry/fs/inode.go +++ b/pkg/sentry/fs/inode.go @@ -261,28 +261,28 @@ func (i *Inode) UnstableAttr(ctx context.Context) (UnstableAttr, error) { return i.InodeOperations.UnstableAttr(ctx, i) } -// Getxattr calls i.InodeOperations.Getxattr with i as the Inode. -func (i *Inode) Getxattr(name string) (string, error) { +// GetXattr calls i.InodeOperations.GetXattr with i as the Inode. +func (i *Inode) GetXattr(ctx context.Context, name string, size uint64) (string, error) { if i.overlay != nil { - return overlayGetxattr(i.overlay, name) + return overlayGetXattr(ctx, i.overlay, name, size) } - return i.InodeOperations.Getxattr(i, name) + return i.InodeOperations.GetXattr(ctx, i, name, size) } -// Setxattr calls i.InodeOperations.Setxattr with i as the Inode. -func (i *Inode) Setxattr(name, value string) error { +// SetXattr calls i.InodeOperations.SetXattr with i as the Inode. +func (i *Inode) SetXattr(ctx context.Context, name, value string, flags uint32) error { if i.overlay != nil { - return overlaySetxattr(i.overlay, name, value) + return overlaySetxattr(ctx, i.overlay, name, value, flags) } - return i.InodeOperations.Setxattr(i, name, value) + return i.InodeOperations.SetXattr(ctx, i, name, value, flags) } -// Listxattr calls i.InodeOperations.Listxattr with i as the Inode. -func (i *Inode) Listxattr() (map[string]struct{}, error) { +// ListXattr calls i.InodeOperations.ListXattr with i as the Inode. +func (i *Inode) ListXattr(ctx context.Context) (map[string]struct{}, error) { if i.overlay != nil { - return overlayListxattr(i.overlay) + return overlayListXattr(ctx, i.overlay) } - return i.InodeOperations.Listxattr(i) + return i.InodeOperations.ListXattr(ctx, i) } // 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 5cde9d215..13261cb81 100644 --- a/pkg/sentry/fs/inode_operations.go +++ b/pkg/sentry/fs/inode_operations.go @@ -170,20 +170,27 @@ type InodeOperations interface { // file system events. UnstableAttr(ctx context.Context, inode *Inode) (UnstableAttr, error) - // Getxattr retrieves the value of extended attribute name. Inodes that - // do not support extended attributes return EOPNOTSUPP. Inodes that - // support extended attributes but don't have a value at name return + // GetXattr retrieves the value of extended attribute specified by name. + // Inodes that do not support extended attributes return EOPNOTSUPP. Inodes + // that support extended attributes but don't have a value at name return // ENODATA. - Getxattr(inode *Inode, name string) (string, error) + // + // If this is called through the getxattr(2) syscall, size indicates the + // size of the buffer that the application has allocated to hold the + // attribute value. If the value is 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. + GetXattr(ctx context.Context, inode *Inode, name string, size uint64) (string, error) - // Setxattr sets the value of extended attribute name. Inodes that - // do not support extended attributes return EOPNOTSUPP. - Setxattr(inode *Inode, name, value string) error + // SetXattr sets the value of extended attribute specified by name. Inodes + // that do not support extended attributes return EOPNOTSUPP. + SetXattr(ctx context.Context, inode *Inode, name, value string, flags uint32) error - // Listxattr returns the set of all extended attributes names that + // ListXattr returns the set of all extended attributes names that // have values. Inodes that do not support extended attributes return // EOPNOTSUPP. - Listxattr(inode *Inode) (map[string]struct{}, error) + ListXattr(ctx context.Context, inode *Inode) (map[string]struct{}, 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 13d11e001..b90da20d0 100644 --- a/pkg/sentry/fs/inode_overlay.go +++ b/pkg/sentry/fs/inode_overlay.go @@ -25,13 +25,13 @@ import ( "gvisor.dev/gvisor/pkg/syserror" ) -func overlayHasWhiteout(parent *Inode, name string) bool { - s, err := parent.Getxattr(XattrOverlayWhiteout(name)) +func overlayHasWhiteout(ctx context.Context, parent *Inode, name string) bool { + s, err := parent.GetXattr(ctx, XattrOverlayWhiteout(name), 1) return err == nil && s == "y" } -func overlayCreateWhiteout(parent *Inode, name string) error { - return parent.InodeOperations.Setxattr(parent, XattrOverlayWhiteout(name), "y") +func overlayCreateWhiteout(ctx context.Context, parent *Inode, name string) error { + return parent.InodeOperations.SetXattr(ctx, parent, XattrOverlayWhiteout(name), "y", 0 /* flags */) } func overlayWriteOut(ctx context.Context, o *overlayEntry) error { @@ -89,7 +89,7 @@ func overlayLookup(ctx context.Context, parent *overlayEntry, inode *Inode, name } // Are we done? - if overlayHasWhiteout(parent.upper, name) { + if overlayHasWhiteout(ctx, parent.upper, name) { if upperInode == nil { parent.copyMu.RUnlock() if negativeUpperChild { @@ -345,7 +345,7 @@ func overlayRemove(ctx context.Context, o *overlayEntry, parent *Dirent, child * } } if child.Inode.overlay.lowerExists { - if err := overlayCreateWhiteout(o.upper, child.name); err != nil { + if err := overlayCreateWhiteout(ctx, o.upper, child.name); err != nil { return err } } @@ -426,7 +426,7 @@ func overlayRename(ctx context.Context, o *overlayEntry, oldParent *Dirent, rena return err } if renamed.Inode.overlay.lowerExists { - if err := overlayCreateWhiteout(oldParent.Inode.overlay.upper, oldName); err != nil { + if err := overlayCreateWhiteout(ctx, oldParent.Inode.overlay.upper, oldName); err != nil { return err } } @@ -528,7 +528,7 @@ func overlayUnstableAttr(ctx context.Context, o *overlayEntry) (UnstableAttr, er return attr, err } -func overlayGetxattr(o *overlayEntry, name string) (string, error) { +func overlayGetXattr(ctx context.Context, o *overlayEntry, name string, size uint64) (string, error) { // Hot path. This is how the overlay checks for whiteout files. // Avoid defers. var ( @@ -544,31 +544,31 @@ func overlayGetxattr(o *overlayEntry, name string) (string, error) { o.copyMu.RLock() if o.upper != nil { - s, err = o.upper.Getxattr(name) + s, err = o.upper.GetXattr(ctx, name, size) } else { - s, err = o.lower.Getxattr(name) + s, err = o.lower.GetXattr(ctx, name, size) } o.copyMu.RUnlock() return s, err } // TODO(b/146028302): Support setxattr for overlayfs. -func overlaySetxattr(o *overlayEntry, name, value string) error { +func overlaySetxattr(ctx context.Context, o *overlayEntry, name, value string, flags uint32) error { return syserror.EOPNOTSUPP } -func overlayListxattr(o *overlayEntry) (map[string]struct{}, error) { +func overlayListXattr(ctx context.Context, o *overlayEntry) (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() + names, err = o.upper.ListXattr(ctx) } else { - names, err = o.lower.Listxattr() + names, err = o.lower.ListXattr(ctx) } for name := range names { - // Same as overlayGetxattr, we shouldn't forward along + // Same as overlayGetXattr, we shouldn't forward along // overlay attributes. if strings.HasPrefix(XattrOverlayPrefix, name) { delete(names, name) diff --git a/pkg/sentry/fs/inode_overlay_test.go b/pkg/sentry/fs/inode_overlay_test.go index 8935aad65..493d98c36 100644 --- a/pkg/sentry/fs/inode_overlay_test.go +++ b/pkg/sentry/fs/inode_overlay_test.go @@ -382,8 +382,8 @@ type dir struct { ReaddirCalled bool } -// Getxattr implements InodeOperations.Getxattr. -func (d *dir) Getxattr(inode *fs.Inode, name string) (string, error) { +// GetXattr implements InodeOperations.GetXattr. +func (d *dir) GetXattr(_ context.Context, _ *fs.Inode, name string, _ uint64) (string, error) { for _, n := range d.negative { if name == fs.XattrOverlayWhiteout(n) { return "y", nil diff --git a/pkg/sentry/fs/tmpfs/tmpfs.go b/pkg/sentry/fs/tmpfs/tmpfs.go index 69089c8a8..0f718e236 100644 --- a/pkg/sentry/fs/tmpfs/tmpfs.go +++ b/pkg/sentry/fs/tmpfs/tmpfs.go @@ -148,19 +148,19 @@ func (d *Dir) CreateFifo(ctx context.Context, dir *fs.Inode, name string, perms return d.ramfsDir.CreateFifo(ctx, dir, name, perms) } -// Getxattr implements fs.InodeOperations.Getxattr. -func (d *Dir) Getxattr(i *fs.Inode, name string) (string, error) { - return d.ramfsDir.Getxattr(i, name) +// GetXattr implements fs.InodeOperations.GetXattr. +func (d *Dir) GetXattr(ctx context.Context, i *fs.Inode, name string, size uint64) (string, error) { + return d.ramfsDir.GetXattr(ctx, i, name, size) } -// Setxattr implements fs.InodeOperations.Setxattr. -func (d *Dir) Setxattr(i *fs.Inode, name, value string) error { - return d.ramfsDir.Setxattr(i, name, value) +// SetXattr implements fs.InodeOperations.SetXattr. +func (d *Dir) SetXattr(ctx context.Context, i *fs.Inode, name, value string, flags uint32) error { + return d.ramfsDir.SetXattr(ctx, i, name, value, flags) } -// Listxattr implements fs.InodeOperations.Listxattr. -func (d *Dir) Listxattr(i *fs.Inode) (map[string]struct{}, error) { - return d.ramfsDir.Listxattr(i) +// 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) } // Lookup implements fs.InodeOperations.Lookup. diff --git a/pkg/sentry/syscalls/linux/linux64_amd64.go b/pkg/sentry/syscalls/linux/linux64_amd64.go index 479c5f6ff..6b2920900 100644 --- a/pkg/sentry/syscalls/linux/linux64_amd64.go +++ b/pkg/sentry/syscalls/linux/linux64_amd64.go @@ -228,10 +228,10 @@ 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), - 188: syscalls.PartiallySupported("setxattr", Setxattr, "Only supported for tmpfs.", nil), + 188: syscalls.PartiallySupported("setxattr", SetXattr, "Only supported for tmpfs.", nil), 189: syscalls.Error("lsetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil), 190: syscalls.Error("fsetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil), - 191: syscalls.PartiallySupported("getxattr", Getxattr, "Only supported for tmpfs.", nil), + 191: syscalls.PartiallySupported("getxattr", GetXattr, "Only supported for tmpfs.", nil), 192: syscalls.ErrorWithEvent("lgetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil), 193: syscalls.ErrorWithEvent("fgetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil), 194: syscalls.ErrorWithEvent("listxattr", syserror.ENOTSUP, "Requires filesystem support.", nil), diff --git a/pkg/sentry/syscalls/linux/linux64_arm64.go b/pkg/sentry/syscalls/linux/linux64_arm64.go index d3f61f5e8..8c1b20911 100644 --- a/pkg/sentry/syscalls/linux/linux64_arm64.go +++ b/pkg/sentry/syscalls/linux/linux64_arm64.go @@ -41,10 +41,10 @@ var ARM64 = &kernel.SyscallTable{ 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), + 5: syscalls.PartiallySupported("setxattr", SetXattr, "Only supported for tmpfs.", nil), 6: syscalls.Error("lsetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil), 7: syscalls.Error("fsetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil), - 8: syscalls.PartiallySupported("getxattr", Getxattr, "Only supported for tmpfs.", nil), + 8: syscalls.PartiallySupported("getxattr", GetXattr, "Only supported for tmpfs.", nil), 9: syscalls.ErrorWithEvent("lgetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil), 10: syscalls.ErrorWithEvent("fgetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil), 11: syscalls.ErrorWithEvent("listxattr", syserror.ENOTSUP, "Requires filesystem support.", nil), diff --git a/pkg/sentry/syscalls/linux/sys_xattr.go b/pkg/sentry/syscalls/linux/sys_xattr.go index 97d9a65ea..816352218 100644 --- a/pkg/sentry/syscalls/linux/sys_xattr.go +++ b/pkg/sentry/syscalls/linux/sys_xattr.go @@ -25,12 +25,12 @@ import ( "gvisor.dev/gvisor/pkg/syserror" ) -// Getxattr implements linux syscall getxattr(2). -func Getxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { +// GetXattr implements linux syscall getxattr(2). +func GetXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { pathAddr := args[0].Pointer() nameAddr := args[1].Pointer() valueAddr := args[2].Pointer() - size := args[3].SizeT() + size := uint64(args[3].SizeT()) path, dirPath, err := copyInPath(t, pathAddr, false /* allowEmpty */) if err != nil { @@ -39,22 +39,28 @@ func Getxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc valueLen := 0 err = fileOpOn(t, linux.AT_FDCWD, path, true /* resolve */, func(root *fs.Dirent, d *fs.Dirent, _ uint) error { - value, err := getxattr(t, d, dirPath, nameAddr) + // If getxattr(2) is called with size 0, the size of the value will be + // returned successfully even if it is nonzero. In that case, we need to + // retrieve the entire attribute value so we can return the correct size. + requestedSize := size + if size == 0 || size > linux.XATTR_SIZE_MAX { + requestedSize = linux.XATTR_SIZE_MAX + } + + value, err := getXattr(t, d, dirPath, nameAddr, uint64(requestedSize)) if err != nil { return err } valueLen = len(value) - if size == 0 { - return nil - } - if size > linux.XATTR_SIZE_MAX { - size = linux.XATTR_SIZE_MAX - } - if valueLen > int(size) { + if uint64(valueLen) > requestedSize { return syserror.ERANGE } + // Skip copying out the attribute value if size is 0. + if size == 0 { + return nil + } _, err = t.CopyOutBytes(valueAddr, []byte(value)) return err }) @@ -64,8 +70,8 @@ func Getxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc return uintptr(valueLen), nil, nil } -// getxattr implements getxattr from the given *fs.Dirent. -func getxattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr usermem.Addr) (string, error) { +// getXattr implements getxattr(2) from the given *fs.Dirent. +func getXattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr usermem.Addr, size uint64) (string, error) { if dirPath && !fs.IsDir(d.Inode.StableAttr) { return "", syserror.ENOTDIR } @@ -83,15 +89,15 @@ func getxattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr usermem.Addr) return "", syserror.EOPNOTSUPP } - return d.Inode.Getxattr(name) + return d.Inode.GetXattr(t, name, size) } -// Setxattr implements linux syscall setxattr(2). -func Setxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { +// SetXattr implements linux syscall setxattr(2). +func SetXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { pathAddr := args[0].Pointer() nameAddr := args[1].Pointer() valueAddr := args[2].Pointer() - size := args[3].SizeT() + size := uint64(args[3].SizeT()) flags := args[4].Uint() path, dirPath, err := copyInPath(t, pathAddr, false /* allowEmpty */) @@ -104,12 +110,12 @@ func Setxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc } return 0, nil, fileOpOn(t, linux.AT_FDCWD, path, true /* resolve */, func(root *fs.Dirent, d *fs.Dirent, _ uint) error { - return setxattr(t, d, dirPath, nameAddr, valueAddr, size, flags) + return setXattr(t, d, dirPath, nameAddr, valueAddr, uint64(size), flags) }) } -// setxattr implements setxattr from the given *fs.Dirent. -func setxattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr, valueAddr usermem.Addr, size uint, flags uint32) error { +// setXattr implements setxattr(2) from the given *fs.Dirent. +func setXattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr, valueAddr usermem.Addr, size uint64, flags uint32) error { if dirPath && !fs.IsDir(d.Inode.StableAttr) { return syserror.ENOTDIR } @@ -136,7 +142,7 @@ func setxattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr, valueAddr us return syserror.EOPNOTSUPP } - return d.Inode.Setxattr(name, value) + return d.Inode.SetXattr(t, name, value, flags) } func copyInXattrName(t *kernel.Task, nameAddr usermem.Addr) (string, error) { |