proc: proc_skip_spaces() shouldn't think it is working on C strings

commit bce9332220 upstream.

proc_skip_spaces() seems to think it is working on C strings, and ends
up being just a wrapper around skip_spaces() with a really odd calling
convention.

Instead of basing it on skip_spaces(), it should have looked more like
proc_skip_char(), which really is the exact same function (except it
skips a particular character, rather than whitespace).  So use that as
inspiration, odd coding and all.

Now the calling convention actually makes sense and works for the
intended purpose.

Reported-and-tested-by: Kyle Zeng <zengyhkyle@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Linus Torvalds 2022-12-05 12:09:06 -08:00 committed by Justin Hammond
parent c83e0b063e
commit f7eb4cfa0e

View file

@ -379,13 +379,14 @@ int proc_dostring(struct ctl_table *table, int write,
ppos);
}
static size_t proc_skip_spaces(char **buf)
static void proc_skip_spaces(char **buf, size_t *size)
{
size_t ret;
char *tmp = skip_spaces(*buf);
ret = tmp - *buf;
*buf = tmp;
return ret;
while (*size) {
if (!isspace(**buf))
break;
(*size)--;
(*buf)++;
}
}
static void proc_skip_char(char **buf, size_t *size, const char v)
@ -632,7 +633,7 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
bool neg;
if (write) {
left -= proc_skip_spaces(&p);
proc_skip_spaces(&p, &left);
if (!left)
break;
@ -659,7 +660,7 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
if (!write && !first && left && !err)
proc_put_char(&buffer, &left, '\n');
if (write && !err && left)
left -= proc_skip_spaces(&p);
proc_skip_spaces(&p, &left);
if (write && first)
return err ? : -EINVAL;
*lenp -= left;
@ -701,7 +702,7 @@ static int do_proc_douintvec_w(unsigned int *tbl_data,
if (left > PAGE_SIZE - 1)
left = PAGE_SIZE - 1;
left -= proc_skip_spaces(&p);
proc_skip_spaces(&p, &left);
if (!left) {
err = -EINVAL;
goto out_free;
@ -721,7 +722,7 @@ static int do_proc_douintvec_w(unsigned int *tbl_data,
}
if (!err && left)
left -= proc_skip_spaces(&p);
proc_skip_spaces(&p, &left);
out_free:
if (err)
@ -1258,7 +1259,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table,
if (write) {
bool neg;
left -= proc_skip_spaces(&p);
proc_skip_spaces(&p, &left);
if (!left)
break;
@ -1286,7 +1287,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table,
if (!write && !first && left && !err)
proc_put_char(&buffer, &left, '\n');
if (write && !err)
left -= proc_skip_spaces(&p);
proc_skip_spaces(&p, &left);
if (write && first)
return err ? : -EINVAL;
*lenp -= left;