PawletOS/external_libudev-zero
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udev_device.c: abort if uevent file is malformed

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illiliti
2021-06-03 06:26:42 +03:00
parent ff6cf67c23
commit 53aa6f3b04
1 changed files with 28 additions and 7 deletions
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35
udev_device.c
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@@ -15,8 +15,8 @@
#define LONG_BIT (sizeof(unsigned long) * 8)
#endif
// https://www.kernel.org/doc/html/latest/input/ff.html#querying-device-capabilities
// https://www.kernel.org/doc/html/latest/input/input-programming.html#bits-to-longs-bit-word-bit-mask
// https://kernel.org/doc/html/latest/input/ff.html#querying-device-capabilities
// https://kernel.org/doc/html/latest/input/input-programming.html#bits-to-longs-bit-word-bit-mask
#define BIT_WORD(x) ((x) / LONG_BIT)
#define BIT_MASK(x) (1UL << ((x) % LONG_BIT))
#define BITS_TO_LONGS(x) (((x) + LONG_BIT - 1) / LONG_BIT)
@@ -377,7 +377,7 @@ static int test_bit(unsigned long *arr, unsigned long bit)
static void set_properties_from_evdev(struct udev_device *udev_device)
{
// https://www.kernel.org/doc/html/latest/driver-api/input.html#c.input_dev
// https://kernel.org/doc/html/latest/driver-api/input.html#c.input_dev
unsigned long prop_bits[BITS_TO_LONGS(INPUT_PROP_CNT)] = {0};
unsigned long abs_bits[BITS_TO_LONGS(ABS_CNT)] = {0};
unsigned long rel_bits[BITS_TO_LONGS(REL_CNT)] = {0};
@@ -603,11 +603,11 @@ struct udev_device *udev_device_new_from_file(struct udev *udev, const char *pat
{
char line[LINE_MAX], syspath[PATH_MAX], devnode[PATH_MAX];
struct udev_device *udev_device;
char *sysname = NULL;
struct stat st;
char *sysname;
FILE *file;
int i, cnt;
char *pos;
int i;
if (stat(path, &st) != 0 || st.st_size > 8192) {
return NULL;
@@ -626,6 +626,8 @@ struct udev_device *udev_device_new_from_file(struct udev *udev, const char *pat
return NULL;
}
cnt = 0;
udev_device->udev = udev;
udev_device->refcount = 1;
udev_device->parent = NULL;
@@ -650,20 +652,39 @@ struct udev_device *udev_device_new_from_file(struct udev *udev, const char *pat
break;
}
}
cnt++;
}
else if (strcmp(line, "DEVNAME=") == 0) {
snprintf(devnode, sizeof(devnode), "/dev/%s", line + 8);
udev_list_entry_add(&udev_device->properties, "DEVNAME", devnode, 0);
}
else if ((pos = strchr(line, '='))) {
else {
pos = strchr(line, '=');
// file is malformed, abort here.
if (!pos) {
cnt = 0;
break;
}
*pos = '\0';
if (strcmp(line, "SUBSYSTEM") == 0 ||
strcmp(line, "ACTION") == 0 ||
strcmp(line, "SEQNUM") == 0) {
cnt++;
}
udev_list_entry_add(&udev_device->properties, line, pos + 1, 0);
}
}
fclose(file);
if (!sysname) {
// https://freedesktop.org/software/systemd/man/udev_device_new_from_environment.html
// > The keys DEVPATH, SUBSYSTEM, ACTION, and SEQNUM are mandatory.
if (cnt != 4) {
udev_device_unref(udev_device);
return NULL;
}