> -----Original Message-----
> From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Andy Green
> Sent: Friday, May 11, 2018 2:47 AM
> To: dev@dpdk.org
> Subject: [dpdk-dev] [PATCH v4 16/18] app/proc-info: sprintf overrun bug
>
> /home/agreen/projects/dpdk/app/proc-info/main.c: In function
> ‘nic_xstats_display’:
> /home/agreen/projects/dpdk/app/proc-info/main.c:495:45:
> error: ‘%s’ directive writing up to 255 bytes into a region of size between
> 165
> and 232 [-Werror=format-overflow=]
> sprintf(buf, "PUTVAL %s/dpdkstat-port.%u/%s-%s N:%"
> ^~
> PRIu64"\n", host_id, port_id, counter_type,
> ~~~~~~~~~~~~
> /home/agreen/projects/dpdk/app/proc-info/main.c:495:4: note:
> ‘sprintf’ output between 31 and 435 bytes into a destination of size 256
> sprintf(buf, "PUTVAL %s/dpdkstat-port.%u/%s-%s N:%"
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> PRIu64"\n", host_id, port_id, counter_type,
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> xstats_names[i].name, values[i]);
>
> Signed-off-by: Andy Green <a...@warmcat.com>
> ---
> app/proc-info/main.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/app/proc-info/main.c b/app/proc-info/main.c index
> 539e13243..df46c235e 100644
> --- a/app/proc-info/main.c
> +++ b/app/proc-info/main.c
> @@ -488,14 +488,19 @@ nic_xstats_display(uint16_t port_id)
> if (enable_collectd_format) {
> char counter_type[MAX_STRING_LEN];
> char buf[MAX_STRING_LEN];
> + size_t n;
>
> collectd_resolve_cnt_type(counter_type,
> sizeof(counter_type),
> xstats_names[i].name);
> - sprintf(buf, "PUTVAL %s/dpdkstat-port.%u/%s-%s N:%"
> + n = snprintf(buf, MAX_STRING_LEN,
> + "PUTVAL %s/dpdkstat-port.%u/%s-%s N:%"
> PRIu64"\n", host_id, port_id, counter_type,
> xstats_names[i].name, values[i]);
> - ret = write(stdout_fd, buf, strlen(buf));
> + buf[sizeof(buf) - 1] = '\0';
No need to NULL terminate, since snprintf already does it.
> + if (n > sizeof(buf) - 1)
> + n = sizeof(buf) - 1;
If (n > sizeof(buf) -1 ), it means that there wasn't enough space to write all
the data,
So shouldn't we return an error here?
> + ret = write(stdout_fd, buf, n);
> if (ret < 0)
> goto err;
> } else {
Missing fixes line and CC stable.
Fixes: 2deb6b5246d7 ("app/procinfo: add collectd format and host id")
Cc: sta...@dpdk.org
