[PATCH] _proc_do_string(): fix short reads
If you try to read things like /proc/sys/kernel/osrelease with single-byte reads, you get just one byte and then EOF. This is because _proc_do_string() assumes that the caller is read()ing into a buffer which is large enough to fit the whole string in a single hit. Fix. Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Michael Tokarev <mjt@tls.msk.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Родитель
c75fb88dbc
Коммит
8d06087714
|
@ -1686,13 +1686,12 @@ static int _proc_do_string(void* data, int maxlen, int write,
|
|||
size_t len;
|
||||
char __user *p;
|
||||
char c;
|
||||
|
||||
if (!data || !maxlen || !*lenp ||
|
||||
(*ppos && !write)) {
|
||||
|
||||
if (!data || !maxlen || !*lenp) {
|
||||
*lenp = 0;
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
if (write) {
|
||||
len = 0;
|
||||
p = buffer;
|
||||
|
@ -1713,6 +1712,15 @@ static int _proc_do_string(void* data, int maxlen, int write,
|
|||
len = strlen(data);
|
||||
if (len > maxlen)
|
||||
len = maxlen;
|
||||
|
||||
if (*ppos > len) {
|
||||
*lenp = 0;
|
||||
return 0;
|
||||
}
|
||||
|
||||
data += *ppos;
|
||||
len -= *ppos;
|
||||
|
||||
if (len > *lenp)
|
||||
len = *lenp;
|
||||
if (len)
|
||||
|
|
Загрузка…
Ссылка в новой задаче