Fix a bug where mount could check the wrong device. st_rdev is the correct

device ID iff the named file is a character or block special device.  Otherwise
it is meaningless junk, in which case st_dev should be used.  This was done
incorrectly, which could cause mount to display bogus mount info.
 -Erik

1 files changed, 5 insertions, 2 deletions

diff --git a/libbb/find_root_device.c b/libbb/find_root_device.c
index c595321df..836ce44d5 100644
--- a/libbb/find_root_device.c
+++ b/libbb/find_root_device.c
@@ -38,8 +38,11 @@ extern char *find_real_root_device_name(const char* name)
         if (stat("/", &rootStat) != 0) 
                 bb_perror_msg("could not stat '/'");
         else {
-                if ((dev = rootStat.st_rdev)==0) 
-                        dev=rootStat.st_dev;
+                /* This check is here in case they pass in /dev name */
+                if ((rootStat.st_mode & S_IFMT) == S_IFBLK)
+                        dev = rootStat.st_rdev;
+                else
+                        dev = rootStat.st_dev;
 
                 dir = opendir("/dev");
                 if (!dir)