Re: [tip:tracing/ftrace] kernel/trace/trace_functions_graph.c: fixnsecs_str buffer size

From: Ingo Molnar
Date: Mon Mar 23 2009 - 13:16:28 EST



* Frederic Weisbecker <fweisbec@xxxxxxxxx> wrote:

> On Mon, Mar 23, 2009 at 04:42:27PM +0000, Daniel Mack wrote:
> > Commit-ID: 603b9b9081ae0a1af986b9059a0a5055876ddea9
> > Gitweb: http://git.kernel.org/tip/603b9b9081ae0a1af986b9059a0a5055876ddea9
> > Author: Daniel Mack <daniel@xxxxxxxx>
> > AuthorDate: Mon, 23 Mar 2009 17:10:37 +0100
> > Committer: Ingo Molnar <mingo@xxxxxxx>
> > CommitDate: Mon, 23 Mar 2009 17:40:51 +0100
> >
> > kernel/trace/trace_functions_graph.c: fix nsecs_str buffer size
> >
> > Impact: fix currently inactive buffer-overflow
> >
> > In kernel/trace/trace_functions_graph.c, print_graph_duration(),
> > len can be as low as 1 or 2, which could make snprintf() write
> > beyond the buffer bounds. (Found by cppcheck, no real-world bug
> > occured)
> >
> > Signed-off-by: Daniel Mack <daniel@xxxxxxxx>
> > Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> > Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> > LKML-Reference: <1237824637-28190-1-git-send-email-daniel@xxxxxxxx>
> > Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
> >
> >
> > ---
> > kernel/trace/trace_functions_graph.c | 2 +-
> > 1 files changed, 1 insertions(+), 1 deletions(-)
>
>
>
> Ingo, as I explained to Daniel before (I should have Cc you),
> there is no overflow to protect here, so this patch will not
> change anything.
>
> This is my bad, I should better comment my code.

Yeah - saw your reply, and zapped the commit already. Please add a
comment in any case.

Ingo
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