Re: [next-20170609][bisected 4d72ba0] WARNING: CPU: 8 PID: 11043 at lib/vsprintf.c:1945 set_precision

From: Joe Perches
Date: Mon Jun 12 2017 - 04:13:01 EST


On Mon, 2017-06-12 at 13:23 +0530, Abdul Haleem wrote:
> Hi Rasmus,
>
> With commit (4d72ba0-lib/vsprintf.c: warn about too large precisions..)
>
> WARN_ONCE is being triggered while running trinity
> $ git clone https://github.com/kernelslacker/trinity.git
> $ cd trinity;./configure;make
> $ ./trinity --dangerous
>
> Machine : Power 8 PowerVM LPAR
> gcc : version 5.2.1
> config : attached
>
>
> In file lib/vsprintf.c at line 1945:
> set_precision(struct printf_spec *spec, int prec)
> {
> spec->precision = prec;
> if (WARN_ONCE(spec->precision != prec, "precision %d too large",
> prec)) {
> spec->precision = clamp(prec, 0, PRECISION_MAX);
> }
> }

Presumably there should be a PATH_MAX maximum check added
to the strlen(name) in get_fs_type.

fs/filesystems.c:271

struct file_system_type *get_fs_type(const char *name)
{
struct file_system_type *fs;
const char *dot = strchr(name, '.');
int len = dot ? dot - name : strlen(name);

fs = __get_fs_type(name, len);
if (!fs && (request_module("fs-%.*s", len, name) == 0))
fs = __get_fs_type(name, len);