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author | netblue30 <netblue30@yahoo.com> | 2016-05-25 09:47:35 -0400 |
---|---|---|
committer | netblue30 <netblue30@yahoo.com> | 2016-05-25 09:47:35 -0400 |
commit | 8ddba33900df5cc7e816dde2f2b4c453f37b32e6 (patch) | |
tree | 4e947965d0eebf221d2ed6ed699cfdaaabeb4f14 | |
parent | Merge pull request #534 from ValdikSS/extra-profiles (diff) | |
parent | Add force-nonewprivs setting (diff) | |
download | firejail-8ddba33900df5cc7e816dde2f2b4c453f37b32e6.tar.gz firejail-8ddba33900df5cc7e816dde2f2b4c453f37b32e6.tar.zst firejail-8ddba33900df5cc7e816dde2f2b4c453f37b32e6.zip |
Merge pull request #536 from KellerFuchs/no_new_privs
Enable using the NO_NEW_PRIVS prctl(2) flag
-rw-r--r-- | README.md | 7 | ||||
-rw-r--r-- | etc/firejail.config | 6 | ||||
-rw-r--r-- | src/firejail/checkcfg.c | 11 | ||||
-rw-r--r-- | src/firejail/firejail.h | 4 | ||||
-rw-r--r-- | src/firejail/main.c | 4 | ||||
-rw-r--r-- | src/firejail/profile.c | 4 | ||||
-rw-r--r-- | src/firejail/sandbox.c | 13 | ||||
-rw-r--r-- | src/firejail/usage.c | 3 | ||||
-rw-r--r-- | src/man/firejail-config.txt | 8 | ||||
-rw-r--r-- | src/man/firejail-profile.txt | 6 | ||||
-rw-r--r-- | src/man/firejail.txt | 7 |
11 files changed, 72 insertions, 1 deletions
@@ -207,6 +207,13 @@ The following features can be enabled or disabled: | |||
207 | 207 | ||
208 | x11 Enable or disable X11 sandboxing support, default enabled. | 208 | x11 Enable or disable X11 sandboxing support, default enabled. |
209 | 209 | ||
210 | force-nonewprivs | ||
211 | Force use of theh NO_NEW_PRIVS prctl(2) flag. | ||
212 | This mitigates the possibility of a user abusing firejail's | ||
213 | features to trick a privileged (suid or file capabilities) | ||
214 | process into loading code or configuration that is partially | ||
215 | under their control. Default disabled | ||
216 | |||
210 | xephyr-screen | 217 | xephyr-screen |
211 | Screen size for --x11=xephyr, default 800x600. Run | 218 | Screen size for --x11=xephyr, default 800x600. Run |
212 | /usr/bin/xrandr for a full list of resolutions available on your | 219 | /usr/bin/xrandr for a full list of resolutions available on your |
diff --git a/etc/firejail.config b/etc/firejail.config index 41cd08e68..caaeb6792 100644 --- a/etc/firejail.config +++ b/etc/firejail.config | |||
@@ -30,6 +30,12 @@ | |||
30 | # Enable or disable X11 sandboxing support, default enabled. | 30 | # Enable or disable X11 sandboxing support, default enabled. |
31 | # x11 yes | 31 | # x11 yes |
32 | 32 | ||
33 | # Force use of nonewprivs. This mitigates the possibility of | ||
34 | # a user abusing firejail's features to trick a privileged (suid | ||
35 | # or file capabilities) process into loading code or configuration | ||
36 | # that is partially under their control. Default disabled | ||
37 | # force-nonewprivs no | ||
38 | |||
33 | # Screen size for --x11=xephyr, default 800x600. Run /usr/bin/xrandr for | 39 | # Screen size for --x11=xephyr, default 800x600. Run /usr/bin/xrandr for |
34 | # a full list of resolutions available on your specific setup. | 40 | # a full list of resolutions available on your specific setup. |
35 | # xephyr-screen 640x480 | 41 | # xephyr-screen 640x480 |
diff --git a/src/firejail/checkcfg.c b/src/firejail/checkcfg.c index 430b0c5a6..4fdbe1897 100644 --- a/src/firejail/checkcfg.c +++ b/src/firejail/checkcfg.c | |||
@@ -36,7 +36,9 @@ int checkcfg(int val) { | |||
36 | int i; | 36 | int i; |
37 | for (i = 0; i < CFG_MAX; i++) | 37 | for (i = 0; i < CFG_MAX; i++) |
38 | cfg_val[i] = 1; // most of them are enabled by default | 38 | cfg_val[i] = 1; // most of them are enabled by default |
39 | |||
39 | cfg_val[CFG_RESTRICTED_NETWORK] = 0; // disabled by default | 40 | cfg_val[CFG_RESTRICTED_NETWORK] = 0; // disabled by default |
41 | cfg_val[CFG_FORCE_NONEWPRIVS ] = 0; // disabled by default | ||
40 | 42 | ||
41 | // open configuration file | 43 | // open configuration file |
42 | char *fname; | 44 | char *fname; |
@@ -106,6 +108,15 @@ int checkcfg(int val) { | |||
106 | else | 108 | else |
107 | goto errout; | 109 | goto errout; |
108 | } | 110 | } |
111 | // nonewprivs | ||
112 | else if (strncmp(ptr, "force-nonewprivs ", 17) == 0) { | ||
113 | if (strcmp(ptr + 17, "yes") == 0) | ||
114 | cfg_val[CFG_SECCOMP] = 1; | ||
115 | else if (strcmp(ptr + 17, "no") == 0) | ||
116 | cfg_val[CFG_SECCOMP] = 0; | ||
117 | else | ||
118 | goto errout; | ||
119 | } | ||
109 | // seccomp | 120 | // seccomp |
110 | else if (strncmp(ptr, "seccomp ", 8) == 0) { | 121 | else if (strncmp(ptr, "seccomp ", 8) == 0) { |
111 | if (strcmp(ptr + 8, "yes") == 0) | 122 | if (strcmp(ptr + 8, "yes") == 0) |
diff --git a/src/firejail/firejail.h b/src/firejail/firejail.h index f4a176caf..661073730 100644 --- a/src/firejail/firejail.h +++ b/src/firejail/firejail.h | |||
@@ -237,6 +237,7 @@ extern int arg_rlimit_nproc; // rlimit nproc | |||
237 | extern int arg_rlimit_fsize; // rlimit fsize | 237 | extern int arg_rlimit_fsize; // rlimit fsize |
238 | extern int arg_rlimit_sigpending;// rlimit sigpending | 238 | extern int arg_rlimit_sigpending;// rlimit sigpending |
239 | extern int arg_nogroups; // disable supplementary groups | 239 | extern int arg_nogroups; // disable supplementary groups |
240 | extern int arg_nonewprivs; // set the NO_NEW_PRIVS prctl | ||
240 | extern int arg_noroot; // create a new user namespace and disable root user | 241 | extern int arg_noroot; // create a new user namespace and disable root user |
241 | extern int arg_netfilter; // enable netfilter | 242 | extern int arg_netfilter; // enable netfilter |
242 | extern int arg_netfilter6; // enable netfilter6 | 243 | extern int arg_netfilter6; // enable netfilter6 |
@@ -565,7 +566,8 @@ void sandboxfs(int op, pid_t pid, const char *patqh); | |||
565 | #define CFG_SECCOMP 5 | 566 | #define CFG_SECCOMP 5 |
566 | #define CFG_NETWORK 6 | 567 | #define CFG_NETWORK 6 |
567 | #define CFG_RESTRICTED_NETWORK 7 | 568 | #define CFG_RESTRICTED_NETWORK 7 |
568 | #define CFG_MAX 8 // this should always be the last entry | 569 | #define CFG_FORCE_NONEWPRIVS 8 |
570 | #define CFG_MAX 9 // this should always be the last entry | ||
569 | int checkcfg(int val); | 571 | int checkcfg(int val); |
570 | 572 | ||
571 | // fs_rdwr.c | 573 | // fs_rdwr.c |
diff --git a/src/firejail/main.c b/src/firejail/main.c index a540d468b..2f4a78d4b 100644 --- a/src/firejail/main.c +++ b/src/firejail/main.c | |||
@@ -77,6 +77,7 @@ int arg_rlimit_nproc = 0; // rlimit nproc | |||
77 | int arg_rlimit_fsize = 0; // rlimit fsize | 77 | int arg_rlimit_fsize = 0; // rlimit fsize |
78 | int arg_rlimit_sigpending = 0; // rlimit fsize | 78 | int arg_rlimit_sigpending = 0; // rlimit fsize |
79 | int arg_nogroups = 0; // disable supplementary groups | 79 | int arg_nogroups = 0; // disable supplementary groups |
80 | int arg_nonewprivs = 0; // set the NO_NEW_PRIVS prctl | ||
80 | int arg_noroot = 0; // create a new user namespace and disable root user | 81 | int arg_noroot = 0; // create a new user namespace and disable root user |
81 | int arg_netfilter; // enable netfilter | 82 | int arg_netfilter; // enable netfilter |
82 | int arg_netfilter6; // enable netfilter6 | 83 | int arg_netfilter6; // enable netfilter6 |
@@ -1367,6 +1368,9 @@ int main(int argc, char **argv) { | |||
1367 | } | 1368 | } |
1368 | } | 1369 | } |
1369 | #endif | 1370 | #endif |
1371 | else if (strcmp(argv[i], "--nonewprivs") == 0) { | ||
1372 | arg_nonewprivs = 1; | ||
1373 | } | ||
1370 | else if (strncmp(argv[i], "--env=", 6) == 0) | 1374 | else if (strncmp(argv[i], "--env=", 6) == 0) |
1371 | env_store(argv[i] + 6); | 1375 | env_store(argv[i] + 6); |
1372 | else if (strncmp(argv[i], "--nosound", 9) == 0) { | 1376 | else if (strncmp(argv[i], "--nosound", 9) == 0) { |
diff --git a/src/firejail/profile.c b/src/firejail/profile.c index 3bf294e00..192f36974 100644 --- a/src/firejail/profile.c +++ b/src/firejail/profile.c | |||
@@ -131,6 +131,10 @@ int profile_check_line(char *ptr, int lineno, const char *fname) { | |||
131 | 131 | ||
132 | return 0; | 132 | return 0; |
133 | } | 133 | } |
134 | else if (strcmp(ptr, "nonewprivs") == 0) { | ||
135 | arg_nonewprivs = 1; | ||
136 | return 0; | ||
137 | } | ||
134 | else if (strcmp(ptr, "seccomp") == 0) { | 138 | else if (strcmp(ptr, "seccomp") == 0) { |
135 | #ifdef HAVE_SECCOMP | 139 | #ifdef HAVE_SECCOMP |
136 | if (checkcfg(CFG_SECCOMP)) | 140 | if (checkcfg(CFG_SECCOMP)) |
diff --git a/src/firejail/sandbox.c b/src/firejail/sandbox.c index 5cfee44d8..6133a610d 100644 --- a/src/firejail/sandbox.c +++ b/src/firejail/sandbox.c | |||
@@ -748,6 +748,19 @@ int sandbox(void* sandbox_arg) { | |||
748 | } | 748 | } |
749 | 749 | ||
750 | //**************************************** | 750 | //**************************************** |
751 | // Set NO_NEW_PRIVS if desired | ||
752 | //**************************************** | ||
753 | if (arg_nonewprivs || checkcfg(CFG_FORCE_NONEWPRIVS)) { | ||
754 | int no_new_privs = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); | ||
755 | |||
756 | if(no_new_privs != 0) | ||
757 | errExit("NO_NEW_PRIVS"); | ||
758 | else if (arg_debug) | ||
759 | printf("NO_NEW_PRIVS set\n"); | ||
760 | } | ||
761 | |||
762 | |||
763 | //**************************************** | ||
751 | // fork the application and monitor it | 764 | // fork the application and monitor it |
752 | //**************************************** | 765 | //**************************************** |
753 | pid_t app_pid = fork(); | 766 | pid_t app_pid = fork(); |
diff --git a/src/firejail/usage.c b/src/firejail/usage.c index ef02c0d72..45bf2e3b1 100644 --- a/src/firejail/usage.c +++ b/src/firejail/usage.c | |||
@@ -157,6 +157,9 @@ void usage(void) { | |||
157 | printf("\tuser. root user does not exist in the new namespace. This option\n"); | 157 | printf("\tuser. root user does not exist in the new namespace. This option\n"); |
158 | printf("\tis not supported for --chroot and --overlay configurations.\n\n"); | 158 | printf("\tis not supported for --chroot and --overlay configurations.\n\n"); |
159 | #endif | 159 | #endif |
160 | printf(" --nonewprivs - sets the NO_NEW_PRIVS prctl - the child processes\n"); | ||
161 | printf("\tcannot gain privileges using execve(2); in particular, this prevents\n"); | ||
162 | printf("\tgaining privileges by calling a suid binary\n\n"); | ||
160 | printf(" --nosound - disable sound system.\n\n"); | 163 | printf(" --nosound - disable sound system.\n\n"); |
161 | 164 | ||
162 | printf(" --output=logfile - stdout logging and log rotation. Copy stdout and stderr\n"); | 165 | printf(" --output=logfile - stdout logging and log rotation. Copy stdout and stderr\n"); |
diff --git a/src/man/firejail-config.txt b/src/man/firejail-config.txt index fcf4109ee..dcede2ec6 100644 --- a/src/man/firejail-config.txt +++ b/src/man/firejail-config.txt | |||
@@ -49,6 +49,14 @@ Enable or disable user namespace support, default enabled. | |||
49 | Enable or disable X11 sandboxing support, default enabled. | 49 | Enable or disable X11 sandboxing support, default enabled. |
50 | 50 | ||
51 | .TP | 51 | .TP |
52 | \fBforce-nonewprivs | ||
53 | Force use of nonewprivs. This mitigates the possibility of | ||
54 | a user abusing firejail's features to trick a privileged (suid | ||
55 | or file capabilities) process into loading code or configuration | ||
56 | that is partially under their control. Default disabled. | ||
57 | |||
58 | |||
59 | .TP | ||
52 | \fBxephyr-screen | 60 | \fBxephyr-screen |
53 | Screen size for --x11=xephyr, default 800x600. Run /usr/bin/xrandr for | 61 | Screen size for --x11=xephyr, default 800x600. Run /usr/bin/xrandr for |
54 | a full list of resolutions available on your specific setup. Examples: | 62 | a full list of resolutions available on your specific setup. Examples: |
diff --git a/src/man/firejail-profile.txt b/src/man/firejail-profile.txt index 4d1de76f5..1f7c8beac 100644 --- a/src/man/firejail-profile.txt +++ b/src/man/firejail-profile.txt | |||
@@ -239,6 +239,12 @@ Enable seccomp filter and blacklist the system calls in the list. | |||
239 | \fBseccomp.keep syscall,syscall,syscall | 239 | \fBseccomp.keep syscall,syscall,syscall |
240 | Enable seccomp filter and whitelist the system calls in the list. | 240 | Enable seccomp filter and whitelist the system calls in the list. |
241 | .TP | 241 | .TP |
242 | \fBnonewprivs | ||
243 | Sets the NO_NEW_PRIVS prctl. This ensures that child processes | ||
244 | cannot acquire new privileges using execve(2); in particular, | ||
245 | this means that calling a suid binary (or one with file capabilities) | ||
246 | does not results in an increase of privilege. | ||
247 | .TP | ||
242 | \fBnoroot | 248 | \fBnoroot |
243 | Use this command to enable an user namespace. The namespace has only one user, the current user. | 249 | Use this command to enable an user namespace. The namespace has only one user, the current user. |
244 | There is no root account (uid 0) defined in the namespace. | 250 | There is no root account (uid 0) defined in the namespace. |
diff --git a/src/man/firejail.txt b/src/man/firejail.txt index 2ea15ff2b..7b22a5bf2 100644 --- a/src/man/firejail.txt +++ b/src/man/firejail.txt | |||
@@ -904,6 +904,13 @@ ping: icmp open socket: Operation not permitted | |||
904 | $ | 904 | $ |
905 | 905 | ||
906 | .TP | 906 | .TP |
907 | \fB\-\-nonewprivs | ||
908 | Sets the NO_NEW_PRIVS prctl. This ensures that child processes | ||
909 | cannot acquire new privileges using execve(2); in particular, | ||
910 | this means that calling a suid binary (or one with file capabilities) | ||
911 | does not results in an increase of privilege. | ||
912 | |||
913 | .TP | ||
907 | \fB\-\-nosound | 914 | \fB\-\-nosound |
908 | Disable sound system. | 915 | Disable sound system. |
909 | .br | 916 | .br |