On Tue, Dec 05, 2023 at 01:41:57PM -0800, Doug Anderson wrote:
> Hi,
>
> On Sun, Nov 19, 2023 at 4:10 PM Yuran Pereira <yuran.pere...@hotmail.com>
> wrote:
> >
> > The function simple_strtoul performs no error checking in scenarios
> > where the input value overflows the intended output variable.
> > This results in this function successfully returning, even when the
> > output does not match the input string (aka the function returns
> > successfully even when the result is wrong).
> >
> > Or as it was mentioned [1], "...simple_strtol(), simple_strtoll(),
> > simple_strtoul(), and simple_strtoull() functions explicitly ignore
> > overflows, which may lead to unexpected results in callers."
> > Hence, the use of those functions is discouraged.
> >
> > This patch replaces all uses of the simple_strtoul with the safer
> > alternatives kstrtoint and kstrtol.
> >
> > [1]
> > https://www.kernel.org/doc/html/latest/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull
> >
> > Signed-off-by: Yuran Pereira <yuran.pere...@hotmail.com>
> > ---
> > kernel/trace/trace_kdb.c | 14 ++++++--------
> > 1 file changed, 6 insertions(+), 8 deletions(-)
> >
> > diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c
> > index 59857a1ee44c..3891f885e4a6 100644
> > --- a/kernel/trace/trace_kdb.c
> > +++ b/kernel/trace/trace_kdb.c
> > @@ -96,23 +96,21 @@ static int kdb_ftdump(int argc, const char **argv)
> > {
> > int skip_entries = 0;
> > long cpu_file;
> > - char *cp;
> > + int err;
> > int cnt;
> > int cpu;
> >
> > if (argc > 2)
> > return KDB_ARGCOUNT;
> >
> > - if (argc) {
> > - skip_entries = simple_strtol(argv[1], &cp, 0);
> > - if (*cp)
> > + if (argc)
> > + if (kstrtoint(argv[1], 0, &skip_entries))
> > skip_entries = 0;
> > - }
>
> Similar nit about braces as in patch #1. tl;dr is change the above to:
>
> if (argc && kstrtoint(argv[1], 0, &skip_entries))
> skip_entries = 0;
Surely that should be:
if (...)
return KDB_BADINT;
There seems little point switching to a "safer" API if we just ignore the
errors it provides us.
Daniel.
