Use android_fork_execvp() instead of system(3) to format filesystems
With the recent selinux changes imposed on vold, it no longer has
permission to run a shell, so invoking the filesystem formatting
commands with system(3) gives an error. So change to using
android_fork_execvp().
Bug: 10279958
Change-Id: Ifa18b28867618858ec7c5cfcc67935e377de38fb
diff --git a/cryptfs.c b/cryptfs.c
index 1e51fd5..03d714e 100644
--- a/cryptfs.c
+++ b/cryptfs.c
@@ -21,6 +21,7 @@
*/
#include <sys/types.h>
+#include <sys/wait.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
@@ -44,6 +45,7 @@
#include "cutils/properties.h"
#include "cutils/android_reboot.h"
#include "hardware_legacy/power.h"
+#include <logwrap/logwrap.h>
#include "VolumeManager.h"
#include "VoldUtil.h"
#include "crypto_scrypt.h"
@@ -244,7 +246,6 @@
off64_t starting_off;
int rc = -1;
char *fname = NULL;
- char key_loc[PROPERTY_VALUE_MAX];
struct stat statbuf;
if (get_crypt_ftr_info(&fname, &starting_off)) {
@@ -255,8 +256,8 @@
SLOGE("Unexpected value for crypto key location\n");
return -1;
}
- if ( (fd = open(fname, O_RDWR)) < 0) {
- SLOGE("Cannot open footer file %s\n", fname);
+ if ( (fd = open(fname, O_RDWR | O_CREAT, 0600)) < 0) {
+ SLOGE("Cannot open footer file %s for put\n", fname);
return -1;
}
@@ -273,7 +274,7 @@
fstat(fd, &statbuf);
/* If the keys are kept on a raw block device, do not try to truncate it. */
- if (S_ISREG(statbuf.st_mode) && (key_loc[0] == '/')) {
+ if (S_ISREG(statbuf.st_mode)) {
if (ftruncate(fd, 0x4000)) {
SLOGE("Cannot set footer file size\n", fname);
goto errout;
@@ -371,7 +372,6 @@
unsigned int nr_sec, cnt;
off64_t starting_off;
int rc = -1;
- char key_loc[PROPERTY_VALUE_MAX];
char *fname = NULL;
struct stat statbuf;
@@ -384,7 +384,7 @@
return -1;
}
if ( (fd = open(fname, O_RDWR)) < 0) {
- SLOGE("Cannot open footer file %s\n", fname);
+ SLOGE("Cannot open footer file %s for get\n", fname);
return -1;
}
@@ -1426,27 +1426,61 @@
static int cryptfs_enable_wipe(char *crypto_blkdev, off64_t size, int type)
{
- char cmdline[256];
+ const char *args[10];
+ char size_str[32]; /* Must be large enough to hold a %lld and null byte */
+ int num_args;
+ int status;
+ int tmp;
int rc = -1;
if (type == EXT4_FS) {
- snprintf(cmdline, sizeof(cmdline), "/system/bin/make_ext4fs -a /data -l %lld %s",
- size * 512, crypto_blkdev);
- SLOGI("Making empty filesystem with command %s\n", cmdline);
+ args[0] = "/system/bin/make_ext4fs";
+ args[1] = "-a";
+ args[2] = "/data";
+ args[3] = "-l";
+ snprintf(size_str, sizeof(size_str), "%lld", size * 512);
+ args[4] = size_str;
+ args[5] = crypto_blkdev;
+ num_args = 6;
+ SLOGI("Making empty filesystem with command %s %s %s %s %s %s\n",
+ args[0], args[1], args[2], args[3], args[4], args[5]);
} else if (type== FAT_FS) {
- snprintf(cmdline, sizeof(cmdline), "/system/bin/newfs_msdos -F 32 -O android -c 8 -s %lld %s",
- size, crypto_blkdev);
- SLOGI("Making empty filesystem with command %s\n", cmdline);
+ args[0] = "/system/bin/newfs_msdos";
+ args[1] = "-F";
+ args[2] = "32";
+ args[3] = "-O";
+ args[4] = "android";
+ args[5] = "-c";
+ args[6] = "8";
+ args[7] = "-s";
+ snprintf(size_str, sizeof(size_str), "%lld", size);
+ args[8] = size_str;
+ args[9] = crypto_blkdev;
+ num_args = 10;
+ SLOGI("Making empty filesystem with command %s %s %s %s %s %s %s %s %s %s\n",
+ args[0], args[1], args[2], args[3], args[4], args[5],
+ args[6], args[7], args[8], args[9]);
} else {
SLOGE("cryptfs_enable_wipe(): unknown filesystem type %d\n", type);
return -1;
}
- if (system(cmdline)) {
- SLOGE("Error creating empty filesystem on %s\n", crypto_blkdev);
+ tmp = android_fork_execvp(num_args, (char **)args, &status, false, true);
+
+ if (tmp != 0) {
+ SLOGE("Error creating empty filesystem on %s due to logwrap error\n", crypto_blkdev);
} else {
- SLOGD("Successfully created empty filesystem on %s\n", crypto_blkdev);
- rc = 0;
+ if (WIFEXITED(status)) {
+ if (WEXITSTATUS(status)) {
+ SLOGE("Error creating filesystem on %s, exit status %d ",
+ crypto_blkdev, WEXITSTATUS(status));
+ } else {
+ SLOGD("Successfully created filesystem on %s\n", crypto_blkdev);
+ rc = 0;
+ }
+ } else {
+ SLOGE("Error creating filesystem on %s, did not exit normally\n", crypto_blkdev);
+ }
}
return rc;