init: stricter checking of major:minor root= values

In the kernel command-line, previously, root=1:2jakshflaksjdhfa would
be accepted and interpreted just like root=1:2. This patch adds
stricter checking so that additional characters after major:minor are
rejected by root=.

The goal of this change is to help in unifying DM's interpretation of
its block device argument by using existing kernel code (name_to_dev_t).
But DM rejects malformed major:minor pairs, it seems reasonable for
root= to reject them as well.

Signed-off-by: Dan Ehrenberg <dehrenberg@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Dan Ehrenberg 2015-02-10 15:20:50 -08:00 коммит произвёл Mike Snitzer
Родитель e6e20a7a5f
Коммит 283e7ad024
1 изменённых файлов: 2 добавлений и 1 удалений

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@ -226,8 +226,9 @@ dev_t name_to_dev_t(const char *name)
if (strncmp(name, "/dev/", 5) != 0) {
unsigned maj, min;
char dummy;
if (sscanf(name, "%u:%u", &maj, &min) == 2) {
if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2) {
res = MKDEV(maj, min);
if (maj != MAJOR(res) || min != MINOR(res))
goto fail;