6 files changed, 72 insertions, 25 deletions

diff --git a/src/firejail/env.c b/src/firejail/env.c
index 54a6b0036..1a6236407 100644
--- a/src/firejail/env.c
+++ b/src/firejail/env.c
@@ -27,12 +27,27 @@ typedef struct env_t {
         struct env_t *next;
         char *name;
         char *value;
+        ENV_OP op;
 } Env;
 static Env *envlist = NULL;
 
 static void env_add(Env *env) {
-        env->next = envlist;
-        envlist = env;
+        env->next = NULL;
+        
+        // add the new entry at the end of the list
+        if (envlist == NULL) {
+                envlist = env;
+                return;
+        }
+        
+        Env *ptr = envlist;
+        while (1) {
+                if (ptr->next == NULL) {
+                        ptr->next = env;
+                        break;
+                }
+                ptr = ptr->next;
+        }
 }
 
 // load IBUS env variables
@@ -87,7 +102,7 @@ void env_ibus_load(void) {
                         if (arg_debug)
                                 printf("%s\n", buf);
                         EUID_USER();
-                        env_store(buf);
+                        env_store(buf, SETENV);
                         EUID_ROOT();
                 }
 
@@ -126,7 +141,7 @@ void env_defaults(void) {
 }
 
 // parse and store the environment setting 
-void env_store(const char *str) {
+void env_store(const char *str, ENV_OP op) {
         EUID_ASSERT();
         assert(str);
         
@@ -134,11 +149,13 @@ void env_store(const char *str) {
         if (*str == '\0')
                 goto errexit;
         char *ptr = strchr(str, '=');
-        if (!ptr)
-                goto errexit;
-        ptr++;
-        if (*ptr == '\0')
-                goto errexit;
+        if (op == SETENV) {
+                if (!ptr)
+                        goto errexit;
+                ptr++;
+                if (*ptr == '\0')
+                        goto errexit;
+        }
 
         // build list entry
         Env *env = malloc(sizeof(Env));
@@ -148,10 +165,13 @@ void env_store(const char *str) {
         env->name = strdup(str);
         if (env->name == NULL)
                 errExit("strdup");
-        char *ptr2 = strchr(env->name, '=');
-        assert(ptr2);
-        *ptr2 = '\0';
-        env->value = ptr2 + 1;
+        if (op == SETENV) {
+                char *ptr2 = strchr(env->name, '=');
+                assert(ptr2);
+                *ptr2 = '\0';
+                env->value = ptr2 + 1;
+        }
+        env->op = op;
         
         // add entry to the list
         env_add(env);
@@ -167,8 +187,13 @@ void env_apply(void) {
         Env *env = envlist;
         
         while (env) {
-                if (setenv(env->name, env->value, 1) < 0)
-                        errExit("setenv");
+                if (env->op == SETENV) {
+                        if (setenv(env->name, env->value, 1) < 0)
+                                errExit("setenv");
+                }
+                else if (env->op == RMENV) {
+                        unsetenv(env->name);
+                }
                 env = env->next;
         }
 }
diff --git a/src/firejail/firejail.h b/src/firejail/firejail.h
index 3d0e9a51b..590646f23 100644
--- a/src/firejail/firejail.h
+++ b/src/firejail/firejail.h
@@ -493,7 +493,12 @@ int check_kernel_procs(void);
 void run_no_sandbox(int argc, char **argv);
 
 // env.c
-void env_store(const char *str);
+typedef enum {
+        SETENV = 0,
+        RMENV
+} ENV_OP;
+
+void env_store(const char *str, ENV_OP op);
 void env_apply(void);
 void env_defaults(void);
 void env_ibus_load(void);
diff --git a/src/firejail/main.c b/src/firejail/main.c
index b1dd7d32c..a0225be15 100644
--- a/src/firejail/main.c
+++ b/src/firejail/main.c
@@ -1465,7 +1465,9 @@ int main(int argc, char **argv) {
                         arg_nonewprivs = 1;
                 }
                 else if (strncmp(argv[i], "--env=", 6) == 0)
-                        env_store(argv[i] + 6);
+                        env_store(argv[i] + 6, SETENV);
+                else if (strncmp(argv[i], "--rmenv=", 8) == 0)
+                        env_store(argv[i] + 8, RMENV);
                 else if (strcmp(argv[i], "--nosound") == 0) {
                         arg_nosound = 1;
                 }
diff --git a/src/firejail/profile.c b/src/firejail/profile.c
index bb834bf19..1106ed84e 100644
--- a/src/firejail/profile.c
+++ b/src/firejail/profile.c
@@ -457,7 +457,11 @@ int profile_check_line(char *ptr, int lineno, const char *fname) {
         }
         
         if (strncmp(ptr, "env ", 4) == 0) {
-                env_store(ptr + 4);
+                env_store(ptr + 4, SETENV);
+                return 0;
+        }
+        if (strncmp(ptr, "rmenv ", 6) == 0) {
+                env_store(ptr + 6, RMENV);
                 return 0;
         }
         
diff --git a/src/firejail/usage.c b/src/firejail/usage.c
index 1efc247b5..b67300618 100644
--- a/src/firejail/usage.c
+++ b/src/firejail/usage.c
@@ -208,6 +208,7 @@ void usage(void) {
         
         printf("    --quiet - turn off Firejail's output.\n\n");
         printf("    --read-only=dirname_or_filename - set directory or file read-only..\n\n");
+        printf("    --read-write=dirname_or_filename - set directory or file read-write..\n\n");
         printf("    --rlimit-fsize=number - set the maximum file size that can be created\n");
         printf("\tby a process.\n\n");
         printf("    --rlimit-nofile=number - set the maximum number of files that can be\n");
@@ -216,7 +217,7 @@ void usage(void) {
         printf("\tcreated for the real user ID of the calling process.\n\n");
         printf("    --rlimit-sigpending=number - set the maximum number of pending signals\n");
         printf("\tfor a process.\n\n");
-        printf("    --read-write=dirname_or_filename - set directory or file read-write..\n\n");
+        printf("    --rmenv=name - remove environment variable in the new sandbox.\n\n");
 #ifdef HAVE_NETWORK     
         printf("    --scan - ARP-scan all the networks from inside a network namespace.\n");
         printf("\tThis makes it possible to detect macvlan kernel device drivers\n");
diff --git a/src/man/firejail.txt b/src/man/firejail.txt
index cb555980d..8d20cf36b 100644
--- a/src/man/firejail.txt
+++ b/src/man/firejail.txt
@@ -1172,6 +1172,15 @@ make the whitelist read-only. Example:
 $ firejail --whitelist=~/work --read-only=~ --read-only=~/work
 
 .TP
+\fB\-\-read-write=dirname_or_filename
+By default, the sandbox mounts system directories read-only.
+These directories are /etc, /var, /usr, /bin, /sbin, /lib, /lib32, /libx32 and /lib64. 
+Use this option to mount read-write files or directories inside the system directories.
+
+This option is available only to root user. It has no effect when --chroot or --overlay are also set. In these
+cases the system directories are mounted read-write.
+
+.TP
 \fB\-\-rlimit-fsize=number
 Set the maximum file size that can be created by a process.
 .TP
@@ -1185,13 +1194,14 @@ Set the maximum number of processes that can be created for the real user ID of
 Set the maximum number of pending signals for a process.
 
 .TP
-\fB\-\-read-write=dirname_or_filename
-By default, the sandbox mounts system directories read-only.
-These directories are /etc, /var, /usr, /bin, /sbin, /lib, /lib32, /libx32 and /lib64. 
-Use this option to mount read-write files or directories inside the system directories.
+\fB\-\-rmenv=name
+Remove environment variable in the new sandbox.
+.br
 
-This option is available only to root user. It has no effect when --chroot or --overlay are also set. In these
-cases the system directories are mounted read-write.
+.br
+Example:
+.br
+$ firejail \-\-rmenv=DBUS_SESSION_BUS_ADDRESS
 
 .TP
 \fB\-\-scan