[LTP] [PATCH] syscalls/pread02: extend buffer to avoid glibc overflow detection

[Jan Stancek]

pushed

On Mon, Jan 31, 2022 at 5:23 PM Cyril Hrubis <chrubis@suse.cz> wrote:
>
> Hi!
> > Test started failing with recent glibc (glibc-2.34.9000-38.fc36),
> > which detects that buffer in pread is potentially too small:
> >   tst_test.c:1431: TINFO: Timeout per run is 0h 05m 00s
> >   *** buffer overflow detected ***: terminated
> >   tst_test.c:1484: TBROK: Test killed by SIGIOT/SIGABRT!
> >
> > (gdb) bt
> >   #0  __pthread_kill_implementation at pthread_kill.c:44
> >   #1  0x00007ffff7e46f73 in __pthread_kill_internal at pthread_kill.c:78
> >   #2  0x00007ffff7df6a36 in __GI_raise at ../sysdeps/posix/raise.c:26
> >   #3  0x00007ffff7de082f in __GI_abort () at abort.c:79
> >   #4  0x00007ffff7e3b01e in __libc_message at ../sysdeps/posix/libc_fatal.c:155
> >   #5  0x00007ffff7ed945a in __GI___fortify_fail at fortify_fail.c:26
> >   #6  0x00007ffff7ed7dc6 in __GI___chk_fail () at chk_fail.c:28
> >   #7  0x00007ffff7ed8214 in __pread_chk at pread_chk.c:26
> >   #8  0x0000000000404d1a in pread at /usr/include/bits/unistd.h:74
> >   #9  verify_pread (n=<optimized out>) at pread02.c:44
> >   #10 0x000000000040dc19 in run_tests () at tst_test.c:1246
> >   #11 testrun () at tst_test.c:1331
> >   #12 fork_testrun () at tst_test.c:1462
> >   #13 0x000000000040e9a1 in tst_run_tcases
> >   #14 0x0000000000404bde in main
> >
> > Extend it to number of bytes we are trying to read from fd.
> >
> > Signed-off-by: Jan Stancek <jstancek@redhat.com>
> > ---
> >  testcases/kernel/syscalls/pread/pread02.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/testcases/kernel/syscalls/pread/pread02.c b/testcases/kernel/syscalls/pread/pread02.c
> > index de2a81fffc37..fda5fd19037c 100644
> > --- a/testcases/kernel/syscalls/pread/pread02.c
> > +++ b/testcases/kernel/syscalls/pread/pread02.c
> > @@ -39,7 +39,7 @@ struct test_case_t {
> >  static void verify_pread(unsigned int n)
> >  {
> >       struct test_case_t *tc = &tcases[n];
> > -     char buf;
> > +     char buf[K1];
>
> Either we do this, or change the nb to 1 in the tcases.
>
> Anyways:
>
> Reviewed-by: Cyril Hrubis <chrubis@suse.cz>
>
> --
> Cyril Hrubis
> chrubis@suse.cz
>