[dpdk-dev] [PATCH] app/test: fix +/-1 error in allocation

[David Marchand]

On Tue, May 3, 2016 at 9:15 PM, Jan Viktorin <viktorin at rehivetech.com> wrote:
> A bug has been detected by valgrind:
>
> ==14406== Invalid write of size 1
> ==14406==    by 0x86ECC76: sprintf (in /usr/lib/libc-2.23.so)
> ==14406==    by 0x430B0A: commands_init (in /home/jviki/Projects/dpdk/dpdk-soc/build/app/test)
> ==14406==    by 0x42F215: main (in /home/jviki/Projects/dpdk/dpdk-soc/build/app/test)
> ==14406==  Address 0x9d72ff2 is 0 bytes after a block of size 1,346 alloc'd
> ==14406==    at 0x78C1BD0: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
> ==14406==    by 0x430AE4: commands_init (in /home/jviki/Projects/dpdk/dpdk-soc/build/app/test)
> ==14406==    by 0x42F215: main (in /home/jviki/Projects/dpdk/dpdk-soc/build/app/test)
> ==14406==
>
> The commands buffer is exactly 1346 B long so there is an access just after
> the buffer. The sprintf always writes '\0' at the end of the string. The '#'
> separator adds 1 B more to each string. This is correct until the last string
> is sprinted there. The last one is 1 B longer then expected, i.e.:
>
>  strlen(t->command) + strlen("#") + ONE_FOR_ZERO
>
> Fixes: 727909c59231 ("app/test: introduce dynamic commands list")
>
> Signed-off-by: Jan Viktorin <viktorin at rehivetech.com>

Good catch.
Acked-by: David Marchand <david.marchand at 6wind.com>

-- 
David Marchand