Fix for 32-bit filesystem capability support.libcap-2.03

Fix a bug related to the unconditional size of the VFS capabilities.
Before, the size was based on the header used to compile the library,
now the default size is based on the process capabilities supported
by the running kernel.

Chris Friedhoff reported this bug.

Signed-off-by: Andrew G. Morgan <morgan@kernel.org>

2 files changed, 11 insertions, 8 deletions

diff --git a/Make.Rules b/Make.Rules
index 8827790..2014f38 100644
--- a/Make.Rules
+++ b/Make.Rules
@@ -41,7 +41,7 @@ LIBDIR=$(FAKEROOT)$(lib_prefix)/$(lib)
 # common defines for libcap
 LIBTITLE=libcap
 VERSION=2
-MINOR=02
+MINOR=03
 #
 
 # Compilation specifics
diff --git a/libcap/cap_file.c b/libcap/cap_file.c
index 16b2f73..d7a2da7 100644
--- a/libcap/cap_file.c
+++ b/libcap/cap_file.c
@@ -82,7 +82,8 @@ static cap_t _fcaps_load(struct vfs_cap_data *rawvfscap, cap_t result,
     return result;
 }
 
-static int _fcaps_save(struct vfs_cap_data *rawvfscap, cap_t cap_d)
+static int _fcaps_save(struct vfs_cap_data *rawvfscap, cap_t cap_d,
+		       int *bytes_p)
 {
     __u32 eff_not_zero, magic;
     unsigned tocopy, i;
@@ -97,6 +98,7 @@ static int _fcaps_save(struct vfs_cap_data *rawvfscap, cap_t cap_d)
     case _LINUX_CAPABILITY_VERSION_1:
 	magic = VFS_CAP_REVISION_1;
 	tocopy = VFS_CAP_U32_1;
+	*bytes_p = XATTR_CAPS_SZ_1;
 	break;
 #endif
 
@@ -104,6 +106,7 @@ static int _fcaps_save(struct vfs_cap_data *rawvfscap, cap_t cap_d)
     case _LINUX_CAPABILITY_VERSION_2:
 	magic = VFS_CAP_REVISION_2;
 	tocopy = VFS_CAP_U32_2;
+	*bytes_p = XATTR_CAPS_SZ_2;
 	break;
 #endif
 
@@ -223,18 +226,18 @@ cap_t cap_get_file(const char *filename)
 int cap_set_fd(int fildes, cap_t cap_d)
 {
     struct vfs_cap_data rawvfscap;
+    int sizeofcaps;
 
     if (cap_d == NULL) {
 	_cap_debug("deleting fildes capabilities");
 	return fremovexattr(fildes, XATTR_NAME_CAPS);
-    } else if (_fcaps_save(&rawvfscap, cap_d) != 0) {
+    } else if (_fcaps_save(&rawvfscap, cap_d, &sizeofcaps) != 0) {
 	return -1;
     }
 
     _cap_debug("setting fildes capabilities");
 
-    return fsetxattr(fildes, XATTR_NAME_CAPS, &rawvfscap,
-		     sizeof(rawvfscap), 0);
+    return fsetxattr(fildes, XATTR_NAME_CAPS, &rawvfscap, sizeofcaps, 0);
 }
 
 /*
@@ -244,17 +247,17 @@ int cap_set_fd(int fildes, cap_t cap_d)
 int cap_set_file(const char *filename, cap_t cap_d)
 {
     struct vfs_cap_data rawvfscap;
+    int sizeofcaps;
 
     if (cap_d == NULL) {
 	_cap_debug("removing filename capabilities");
 	return removexattr(filename, XATTR_NAME_CAPS);
-    } else if (_fcaps_save(&rawvfscap, cap_d) != 0) {
+    } else if (_fcaps_save(&rawvfscap, cap_d, &sizeofcaps) != 0) {
 	return -1;
     }
 
     _cap_debug("setting filename capabilities");
-    return setxattr(filename, XATTR_NAME_CAPS, &rawvfscap,
-		    sizeof(rawvfscap), 0);
+    return setxattr(filename, XATTR_NAME_CAPS, &rawvfscap, sizeofcaps, 0);
 }
 
 #else /* ie. ndef VFS_CAP_U32 */