lkml.org 
[lkml]   [2017]   [Oct]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 2/5] trace-cmd: Fix NULL pointer being passed to memcpy
    On Mon, Oct 09, 2017 at 06:24:32PM -0400, Steven Rostedt wrote:
    > On Sat, 12 Aug 2017 11:30:44 -0600
    > Michael Sartain <mikesart@fastmail.com> wrote:
    >
    > > Signed-off-by: Michael Sartain <mikesart@fastmail.com>
    > > ---
    > > trace-output.c | 6 +++++-
    > > 1 file changed, 5 insertions(+), 1 deletion(-)
    > >
    > > diff --git a/trace-output.c b/trace-output.c
    > > index bfe6331..84b21b0 100644
    > > --- a/trace-output.c
    > > +++ b/trace-output.c
    > > @@ -929,7 +929,11 @@ tracecmd_add_option(struct tracecmd_output *handle,
    > > free(option);
    > > return NULL;
    > > }
    > > - memcpy(option->data, data, size);
    > > +
    > > + /* Some IDs (like TRACECMD_OPTION_TRACECLOCK) pass NULL data */
    > > + if (data)
    > > + memcpy(option->data, data, size);
    >
    > Is this a problem, as when this happens, size should be zero. Does it
    > crash with data=NULL and size=0, or have you seen size not be zero?

    I got an ASAN warning, but you are correct - the size was 0 and it did
    not crash.

    \
     
     \ /
      Last update: 2017-10-10 00:27    [W:3.028 / U:0.020 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site