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-rw-r--r--pkg/sentry/syscalls/linux/linux64_amd64.go27
-rw-r--r--pkg/sentry/syscalls/linux/linux64_arm64.go37
-rw-r--r--pkg/sentry/syscalls/linux/sys_xattr.go200
3 files changed, 220 insertions, 44 deletions
diff --git a/pkg/sentry/syscalls/linux/linux64_amd64.go b/pkg/sentry/syscalls/linux/linux64_amd64.go
index 588f8b087..79066ad2a 100644
--- 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 100644
--- 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 100644
--- 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)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-02 09:27:51 +0000