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authorkay.sievers@vrfy.org <kay.sievers@vrfy.org>2004-02-26 19:40:22 -0800
committerGreg KH <gregkh@suse.de>2005-04-26 21:32:30 -0700
commit831f800da34ddb449aecae925cd1f154f20b1eed (patch)
treee58de05592252bab5a83fca240941be313cba94b
parentbef370d6ebd6707cc2ef183c2dc83f4a62d8111b (diff)
[PATCH] udev - safer string handling - part two
As promised, here is the next round. We provide in addition to the already used macros: strfieldcpy(to, from) strfieldcat(to, from) the corresponding friends, if the size of the target is not known and must be provided by the caller: strnfieldcpy(to, from, maxsize) strnfieldcat(to, from, maxsize) and switch nearly all possibly unsafe users of strcat(), strncat(), strcpy() and strncpy() to these safer macros. The last known remaining issue seems the use of sprintf() and snprintf(). I will take on it later today or tomorrow.
-rw-r--r--namedev.c31
-rw-r--r--udev.h14
-rw-r--r--udev_config.c2
3 files changed, 32 insertions, 15 deletions
diff --git a/namedev.c b/namedev.c
index 219cb8a4b8..f688507dc3 100644
--- a/namedev.c
+++ b/namedev.c
@@ -209,7 +209,9 @@ static int get_format_len(char **str)
return -1;
}
-static void apply_format(struct udevice *udev, unsigned char *string, struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
+static void apply_format(struct udevice *udev, char *string, size_t maxsize,
+ struct sysfs_class_device *class_dev,
+ struct sysfs_device *sysfs_device)
{
char temp[NAME_SIZE];
char temp1[NAME_SIZE];
@@ -245,19 +247,19 @@ static void apply_format(struct udevice *udev, unsigned char *string, struct sys
case 'b':
if (strlen(udev->bus_id) == 0)
break;
- strcat(pos, udev->bus_id);
+ strnfieldcat(pos, udev->bus_id, maxsize);
dbg("substitute bus_id '%s'", udev->bus_id);
break;
case 'k':
if (strlen(udev->kernel_name) == 0)
break;
- strcat(pos, udev->kernel_name);
+ strnfieldcat(pos, udev->kernel_name, maxsize);
dbg("substitute kernel name '%s'", udev->kernel_name);
break;
case 'n':
if (strlen(udev->kernel_number) == 0)
break;
- strcat(pos, udev->kernel_number);
+ strnfieldcat(pos, udev->kernel_number, maxsize);
dbg("substitute kernel number '%s'", udev->kernel_number);
break;
case 'm':
@@ -287,11 +289,11 @@ static void apply_format(struct udevice *udev, unsigned char *string, struct sys
}
}
if (pos3) {
- strcat(pos, pos3);
+ strnfieldcat(pos, pos3, maxsize);
dbg("substitute part of result string '%s'", pos3);
}
} else {
- strcat(pos, udev->program_result);
+ strnfieldcat(pos, udev->program_result, maxsize);
dbg("substitute result string '%s'", udev->program_result);
}
break;
@@ -302,20 +304,20 @@ static void apply_format(struct udevice *udev, unsigned char *string, struct sys
dbg("sysfa attribute '%s' not found", attr);
break;
}
- strcpy(pos, tmpattr->value);
+ strnfieldcpy(pos, tmpattr->value, maxsize);
dbg("substitute sysfs value '%s'", tmpattr->value);
} else {
dbg("missing attribute");
}
break;
case '%':
- strcat(pos, "%");
+ strnfieldcat(pos, "%", maxsize);
break;
default:
dbg("unknown substitution type '%%%c'", c);
break;
}
- strcat(pos, tail);
+ strnfieldcat(pos, tail, maxsize);
}
}
@@ -462,7 +464,7 @@ static int execute_program(char *path, char *value, int len)
strncpy(value, buffer, len);
pos = value + strlen(value)-1;
if (pos[0] == '\n')
- pos[0] = '\0';
+ pos[0] = '\0';
dbg("result is '%s'", value);
}
}
@@ -733,7 +735,8 @@ static int match_rule(struct config_device *dev, struct sysfs_class_device *clas
/* execute external program */
if (dev->program[0] != '\0') {
dbg("check " FIELD_PROGRAM);
- apply_format(udev, dev->program, class_dev, sysfs_device);
+ apply_format(udev, dev->program, sizeof(dev->program),
+ class_dev, sysfs_device);
if (execute_program(dev->program, udev->program_result, NAME_SIZE) != 0) {
dbg(FIELD_PROGRAM " returned nozero");
goto try_parent;
@@ -825,8 +828,10 @@ int namedev_name_device(struct sysfs_class_device *class_dev, struct udevice *ud
found:
/* substitute placeholder */
- apply_format(udev, udev->name, class_dev, sysfs_device);
- apply_format(udev, udev->symlink, class_dev, sysfs_device);
+ apply_format(udev, udev->name, sizeof(udev->name),
+ class_dev, sysfs_device);
+ apply_format(udev, udev->symlink, sizeof(udev->symlink),
+ class_dev, sysfs_device);
udev->partitions = dev->partitions;
done:
perm = find_perm(udev->name);
diff --git a/udev.h b/udev.h
index fc44a9847c..0ce010f3c4 100644
--- a/udev.h
+++ b/udev.h
@@ -64,7 +64,19 @@ do { \
#define strfieldcat(to, from) \
do { \
to[sizeof(to)-1] = '\0'; \
- strncat(to, from, sizeof(to) - strlen(to) -1); \
+ strncat(to, from, sizeof(to) - strlen(to)-1); \
+} while (0)
+
+#define strnfieldcpy(to, from, maxsize) \
+do { \
+ to[maxsize-1] = '\0'; \
+ strncpy(to, from, maxsize-1); \
+} while (0)
+
+#define strnfieldcat(to, from, maxsize) \
+do { \
+ to[maxsize-1] = '\0'; \
+ strncat(to, from, maxsize - strlen(to)-1); \
} while (0)
extern int udev_add_device(char *path, char *subsystem, int fake);
diff --git a/udev_config.c b/udev_config.c
index cade81cf20..de83ef9c4c 100644
--- a/udev_config.c
+++ b/udev_config.c
@@ -81,7 +81,7 @@ static void init_variables(void)
#define set_var(_name, _var) \
if (strcasecmp(variable, _name) == 0) { \
dbg_parse("%s = '%s'", _name, value); \
- strncpy(_var, value, sizeof(_var)); \
+ strnfieldcpy(_var, value, sizeof(_var));\
}
#define set_bool(_name, _var) \