1 files changed, 42 insertions, 13 deletions

diff --git a/src/firejail/util.c b/src/firejail/util.c
index 28ad6b990..d6835569d 100644
--- a/src/firejail/util.c
+++ b/src/firejail/util.c
@@ -1037,32 +1037,61 @@ static MountData mdata;
 // The return value points to a static area, and will be overwritten by subsequent calls.
 // The function does an exit(1) if anything goes wrong.
 MountData *get_last_mount(void) {
-        // open /proc/self/mounts
-        FILE *fp = fopen("/proc/self/mounts", "r");
+        // open /proc/self/mountinfo
+        FILE *fp = fopen("/proc/self/mountinfo", "r");
         if (!fp)
                 goto errexit;
 
         mbuf[0] = '\0';
         while (fgets(mbuf, MAX_BUF, fp));
         fclose(fp);
-        if (arg_debug || arg_debug_whitelists)
+        if (arg_debug)
                 printf("%s", mbuf);
 
-        // extract filesystem name and directory
-        mdata.fsname = mbuf;
-        mdata.dir = strstr(mbuf, " ");
-        if (!mdata.dir)
+        // extract filesystem name, directory and filesystem type
+        // examples:
+        //      587 543 8:1 /tmp /etc rw,relatime master:1 - ext4 /dev/sda1 rw,errors=remount-ro,data=ordered
+        //              mdata.fsname: /tmp
+        //              mdata.dir: /etc
+        //              mdata.fstype: ext4
+        //      585 564 0:76 / /home/netblue/.cache rw,nosuid,nodev - tmpfs tmpfs rw
+        //              mdata.fsname: /
+        //              mdata.dir: /home/netblue/.cache
+        //              mdata.fstype: tmpfs
+        memset(&mdata, 0, sizeof(mdata));
+        char *ptr = strtok(mbuf, " ");
+        if (!ptr)
                 goto errexit;
-        *mdata.dir = '\0';
-        mdata.dir++;
-        char *end = strstr(mdata.dir, " ");
-        if (!end)
+
+        int cnt = 1;
+        while ((ptr = strtok(NULL, " ")) != NULL) {
+                cnt++;
+                if (cnt == 4)
+                        mdata.fsname = ptr;
+                else if (cnt == 5) {
+                        mdata.dir = ptr;
+                        break;
+                }
+        }
+
+        ptr = strtok(NULL, "-");
+        if (!ptr)
+                goto errexit;
+
+        ptr = strtok(NULL, " ");
+        if (!ptr)
                 goto errexit;
-        *end = '\0';
+        mdata.fstype = ptr++;
 
+        if (mdata.fsname == NULL ||
+            mdata.dir == NULL ||
+            mdata.fstype == NULL)
+                goto errexit;
+        if (arg_debug)
+                printf("fsname=%s dir=%s fstype=%s\n", mdata.fsname, mdata.dir, mdata.fstype);
         return &mdata;
 
 errexit:
-        fprintf(stderr, "Error: cannot read /proc/self/mounts");
+        fprintf(stderr, "Error: cannot read /proc/self/mountinfo\n");
         exit(1);
 }