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 Greg Kroah-Hartman
parent e042205188
commit fdf2c95f28
1 changed files with 13 additions and 12 deletions

View File

@ -265,13 +265,14 @@ int proc_dostring(struct ctl_table *table, int write,
ppos); ppos);
} }
static size_t proc_skip_spaces(char **buf) static void proc_skip_spaces(char **buf, size_t *size)
{ {
size_t ret; while (*size) {
char *tmp = skip_spaces(*buf); if (!isspace(**buf))
ret = tmp - *buf; break;
*buf = tmp; (*size)--;
return ret; (*buf)++;
}
} }
static void proc_skip_char(char **buf, size_t *size, const char v) static void proc_skip_char(char **buf, size_t *size, const char v)
@ -518,7 +519,7 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
bool neg; bool neg;
if (write) { if (write) {
left -= proc_skip_spaces(&p); proc_skip_spaces(&p, &left);
if (!left) if (!left)
break; break;
@ -545,7 +546,7 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
if (!write && !first && left && !err) if (!write && !first && left && !err)
proc_put_char(&buffer, &left, '\n'); proc_put_char(&buffer, &left, '\n');
if (write && !err && left) if (write && !err && left)
left -= proc_skip_spaces(&p); proc_skip_spaces(&p, &left);
if (write && first) if (write && first)
return err ? : -EINVAL; return err ? : -EINVAL;
*lenp -= left; *lenp -= left;
@ -587,7 +588,7 @@ static int do_proc_douintvec_w(unsigned int *tbl_data,
if (left > PAGE_SIZE - 1) if (left > PAGE_SIZE - 1)
left = PAGE_SIZE - 1; left = PAGE_SIZE - 1;
left -= proc_skip_spaces(&p); proc_skip_spaces(&p, &left);
if (!left) { if (!left) {
err = -EINVAL; err = -EINVAL;
goto out_free; goto out_free;
@ -607,7 +608,7 @@ static int do_proc_douintvec_w(unsigned int *tbl_data,
} }
if (!err && left) if (!err && left)
left -= proc_skip_spaces(&p); proc_skip_spaces(&p, &left);
out_free: out_free:
if (err) if (err)
@ -1072,7 +1073,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table,
if (write) { if (write) {
bool neg; bool neg;
left -= proc_skip_spaces(&p); proc_skip_spaces(&p, &left);
if (!left) if (!left)
break; break;
@ -1101,7 +1102,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table,
if (!write && !first && left && !err) if (!write && !first && left && !err)
proc_put_char(&buffer, &left, '\n'); proc_put_char(&buffer, &left, '\n');
if (write && !err) if (write && !err)
left -= proc_skip_spaces(&p); proc_skip_spaces(&p, &left);
if (write && first) if (write && first)
return err ? : -EINVAL; return err ? : -EINVAL;
*lenp -= left; *lenp -= left;