library: protect against large version numbers.

Linux release numbers are x.y.z we assumed but never protected
against x> 0x7fff and y,z > 0xff before.

Linux release in 1991, 1 major release per 6 years so we're fine
until 7452, unless they do way too many minor rels (max being 39)

diff --git a/doc/procps_linux_version.3 b/doc/procps_linux_version.3
index 838854bf12590af7ae7b70869dd7a3eb0e301784..b284d13eecf276f0bc4babbd40ad5d3d528bf672 100644 (file)
--- a/doc/procps_linux_version.3
+++ b/doc/procps_linux_version.3
@@ -16,7 +16,7 @@
 .\" Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 .\" %%%LICENSE_END
 .\"
-.TH PROCPS_LINUX_VERSION 3 2016-04-14 "libproc-2"
+.TH PROCPS_LINUX_VERSION 3 2016-05-01 "libproc-2"
 .\" Please adjust this date whenever revising the manpage.
 .\"
 .SH NAME
@@ -79,6 +79,15 @@ Contains the release version of the Linux kernel or proc filesystem.
 .B procps_linux_version()
 first appeared in libproc-2 version 0.0.
 
+.SH BUGS
+Due to the way the three numbers are encoded into a single integer,
+.BR procps_linux_version ()
+and the associated macros assume 255 for the maximum value for the
+minor and patch level and 32767 (hex 0x7fff) for the maximum value
+for the major version. In other words, when Linux v 32768.0.0 comes
+out, this function will break.
+.\" Maj/6yr - In 7452 we'll think of something
+
 .SH SEE ALSO
 .BR fopen (3),
 .BR proc (5).

diff --git a/proc/version.h b/proc/version.h
index ba86250babd9d10d25c29fd5235d78d750dc0b60..611b4a7f2ee2712d046ecad1786b88eb28c5a430 100644 (file)
--- a/proc/version.h
+++ b/proc/version.h
@@ -29,7 +29,7 @@ __BEGIN_DECLS
 int procps_linux_version(void);
 
 /* Convenience macros for composing/decomposing version codes */
-#define LINUX_VERSION(x,y,z)   (0x10000*(x) + 0x100*(y) + z)
+#define LINUX_VERSION(x,y,z)   (0x10000*((x)&0x7fff) + 0x100*((y)&0xff) + (z)&0xff)
 #define LINUX_VERSION_MAJOR(x) (((x)>>16) & 0xFF)
 #define LINUX_VERSION_MINOR(x) (((x)>> 8) & 0xFF)
 #define LINUX_VERSION_PATCH(x) ( (x)      & 0xFF)