diff mbox series

[2/2] tracing/probes: Fix to exit fetching if an error is detected

Message ID 168804802668.2028538.4634073314317984220.stgit@mhiramat.roam.corp.google.com
State New
Headers
Series [1/2] tracing/probes: Fix to avoid double count of the string length on the array |

Commit Message

Masami Hiramatsu (Google) June 29, 2023, 2:13 p.m. UTC 
  From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Fix to exit fetching arguments if an error is detected when storing
strings. Without this fix, if an array is specified with string types
it may point wrong address to store the data.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/8819b154-2ba1-43c3-98a2-cbde20892023@moroto.mountain/
Fixes: 9b960a38835f ("tracing: probeevent: Unify fetch_insn processing common part")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
 kernel/trace/trace_probe_tmpl.h |    2 ++
 1 file changed, 2 insertions(+)

Comments

Steven Rostedt July 2, 2023, 1:16 a.m. UTC | #1 
On Thu, 29 Jun 2023 23:13:46 +0900
"Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:

> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> 
> Fix to exit fetching arguments if an error is detected when storing
> strings. Without this fix, if an array is specified with string types
> it may point wrong address to store the data.

  "it may store that data at the wrong address".

> 
> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> Closes: https://lore.kernel.org/all/8819b154-2ba1-43c3-98a2-cbde20892023@moroto.mountain/
> Fixes: 9b960a38835f ("tracing: probeevent: Unify fetch_insn processing common part")
> Cc: stable@vger.kernel.org
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> ---
>  kernel/trace/trace_probe_tmpl.h |    2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h
> index 4735c5cb76fa..d6f2bf69f9bc 100644
> --- a/kernel/trace/trace_probe_tmpl.h
> +++ b/kernel/trace/trace_probe_tmpl.h
> @@ -193,6 +193,8 @@ process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val,
>  	default:
>  		return -EILSEQ;
>  	}
> +	if (ret < 0)
> +		return ret;

Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>

-- Steve

>  	code++;
>  
>  	/* 4th stage: modify stored value if needed */
Masami Hiramatsu (Google) July 2, 2023, 1:46 p.m. UTC | #2 
On Sat, 1 Jul 2023 21:16:17 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> On Thu, 29 Jun 2023 23:13:46 +0900
> "Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
> 
> > From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> > 
> > Fix to exit fetching arguments if an error is detected when storing
> > strings. Without this fix, if an array is specified with string types
> > it may point wrong address to store the data.
> 
>   "it may store that data at the wrong address".

Good catch! Yes, while updating the data location, the remaining length
and offset becomes wrong and next array element (string) will be stored
in wrong memory address.

> 
> > 
> > Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> > Closes: https://lore.kernel.org/all/8819b154-2ba1-43c3-98a2-cbde20892023@moroto.mountain/
> > Fixes: 9b960a38835f ("tracing: probeevent: Unify fetch_insn processing common part")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> > ---
> >  kernel/trace/trace_probe_tmpl.h |    2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h
> > index 4735c5cb76fa..d6f2bf69f9bc 100644
> > --- a/kernel/trace/trace_probe_tmpl.h
> > +++ b/kernel/trace/trace_probe_tmpl.h
> > @@ -193,6 +193,8 @@ process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val,
> >  	default:
> >  		return -EILSEQ;
> >  	}
> > +	if (ret < 0)
> > +		return ret;
> 
> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Thanks!

> 
> -- Steve
> 
> >  	code++;
> >  
> >  	/* 4th stage: modify stored value if needed */
>
diff mbox series

Patch

diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h
index 4735c5cb76fa..d6f2bf69f9bc 100644
--- a/kernel/trace/trace_probe_tmpl.h
+++ b/kernel/trace/trace_probe_tmpl.h
@@ -193,6 +193,8 @@  process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val,
 	default:
 		return -EILSEQ;
 	}
+	if (ret < 0)
+		return ret;
 	code++;
 
 	/* 4th stage: modify stored value if needed */