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

[Cyril Hrubis]

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