[Libguestfs] [PATCH] mknod: filter modes in mkfifo, mknod_b, mknod_c (RHBZ#1182463).

[Pino Toscano]

Since mkfifo, mknod_b, and mknod_c add the correct file type to the
modes of the resulting file, make sure the specified mode contains only
permissions bits.
---
 daemon/mknod.c       | 15 +++++++++++++++
 generator/actions.ml | 21 ++++++++++++++++++---
 2 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/daemon/mknod.c b/daemon/mknod.c
index 7f71210..9af8701 100644
--- a/daemon/mknod.c
+++ b/daemon/mknod.c
@@ -38,6 +38,15 @@ optgroup_mknod_available (void)
   return 1;
 }
 
+#define CHECK_MODE \
+  do { \
+    if ((mode & ~07777) != 0) { \
+      reply_with_error ("%o: mode must specify only file permission bits", \
+                        (unsigned int) mode); \
+      return -1; \
+    } \
+  } while (0)
+
 int
 do_mknod (int mode, int devmajor, int devminor, const char *path)
 {
@@ -63,18 +72,24 @@ do_mknod (int mode, int devmajor, int devminor, const char *path)
 int
 do_mkfifo (int mode, const char *path)
 {
+  CHECK_MODE;
+
   return do_mknod (mode | S_IFIFO, 0, 0, path);
 }
 
 int
 do_mknod_b (int mode, int devmajor, int devminor, const char *path)
 {
+  CHECK_MODE;
+
   return do_mknod (mode | S_IFBLK, devmajor, devminor, path);
 }
 
 int
 do_mknod_c (int mode, int devmajor, int devminor, const char *path)
 {
+  CHECK_MODE;
+
   return do_mknod (mode | S_IFCHR, devmajor, devminor, path);
 }
 
diff --git a/generator/actions.ml b/generator/actions.ml
index 96a9dd6..c48ad1a 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -6173,7 +6173,9 @@ The mode actually set is affected by the umask." };
       InitScratchFS, Always, TestResult (
         [["mkfifo"; "0o777"; "/mkfifo"];
          ["stat"; "/mkfifo"]],
-        "S_ISFIFO (ret->mode) && (ret->mode & 0777) == 0755"), []
+        "S_ISFIFO (ret->mode) && (ret->mode & 0777) == 0755"), [];
+      InitScratchFS, Always, TestLastFail (
+        [["mkfifo"; "0o20777"; "/mkfifo-2"]]), [];
     ];
     shortdesc = "make FIFO (named pipe)";
     longdesc = "\
@@ -6181,6 +6183,9 @@ This call creates a FIFO (named pipe) called C<path> with
 mode C<mode>.  It is just a convenient wrapper around
 C<guestfs_mknod>.
 
+Unlike with C<guestfs_mknod>, C<mode> B<must> contain only permissions
+bits.
+
 The mode actually set is affected by the umask." };
 
   { defaults with
@@ -6192,7 +6197,9 @@ The mode actually set is affected by the umask." };
       InitScratchFS, Always, TestResult (
         [["mknod_b"; "0o777"; "99"; "66"; "/mknod_b"];
          ["stat"; "/mknod_b"]],
-        "S_ISBLK (ret->mode) && (ret->mode & 0777) == 0755"), []
+        "S_ISBLK (ret->mode) && (ret->mode & 0777) == 0755"), [];
+      InitScratchFS, Always, TestLastFail (
+        [["mknod_b"; "0o10777"; "99"; "66"; "/mknod_b-2"]]), [];
     ];
     shortdesc = "make block device node";
     longdesc = "\
@@ -6200,6 +6207,9 @@ This call creates a block device node called C<path> with
 mode C<mode> and device major/minor C<devmajor> and C<devminor>.
 It is just a convenient wrapper around C<guestfs_mknod>.
 
+Unlike with C<guestfs_mknod>, C<mode> B<must> contain only permissions
+bits.
+
 The mode actually set is affected by the umask." };
 
   { defaults with
@@ -6211,7 +6221,9 @@ The mode actually set is affected by the umask." };
       InitScratchFS, Always, TestResult (
         [["mknod_c"; "0o777"; "99"; "66"; "/mknod_c"];
          ["stat"; "/mknod_c"]],
-        "S_ISCHR (ret->mode) && (ret->mode & 0777) == 0755"), []
+        "S_ISCHR (ret->mode) && (ret->mode & 0777) == 0755"), [];
+      InitScratchFS, Always, TestLastFail (
+        [["mknod_c"; "0o20777"; "99"; "66"; "/mknod_c-2"]]), [];
     ];
     shortdesc = "make char device node";
     longdesc = "\
@@ -6219,6 +6231,9 @@ This call creates a char device node called C<path> with
 mode C<mode> and device major/minor C<devmajor> and C<devminor>.
 It is just a convenient wrapper around C<guestfs_mknod>.
 
+Unlike with C<guestfs_mknod>, C<mode> B<must> contain only permissions
+bits.
+
 The mode actually set is affected by the umask." };
 
   { defaults with
-- 
1.9.3