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From: Andy Green <andy@warmcat.com>
To: "De Lara Guarch, Pablo" <pablo.de.lara.guarch@intel.com>,
	"dev@dpdk.org" <dev@dpdk.org>
Cc: "Pattan, Reshma" <reshma.pattan@intel.com>,
	"stable@dpdk.org" <stable@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v4 16/18] app/proc-info: sprintf overrun bug
Date: Sat, 12 May 2018 09:33:17 +0800	[thread overview]
Message-ID: <e47972c5-9308-6cf5-05c1-2a7b385ab01d@warmcat.com> (raw)
In-Reply-To: <E115CCD9D858EF4F90C690B0DCB4D8976CD08D09@IRSMSX108.ger.corp.intel.com>



On 05/11/2018 08:26 PM, De Lara Guarch, Pablo wrote:
> 
> 
>> -----Original Message-----
>> From: dev [mailto:dev-bounces@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 <andy@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.

OK.

>> +			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?

It's just logging stuff, policy about truncated overlength logs could go 
either way.

Prior to this patch its policy was to corrupt your stack if overlength 
;-) so I think it's moving it on in the right direction merely 
truncating it.

-Andy

>> +			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: stable@dpdk.org
> 

  reply	other threads:[~2018-05-12  1:33 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-11  1:45 [dpdk-dev] [PATCH v4 00/18] Fix default build on gcc8.0.1 Andy Green
2018-05-11  1:45 ` [dpdk-dev] [PATCH v4 01/18] devtools/check-git: provide more generic grep pattern Andy Green
2018-05-11  8:11   ` De Lara Guarch, Pablo
2018-05-11  1:45 ` [dpdk-dev] [PATCH v4 02/18] net/nfp: solve buffer overflow Andy Green
2018-05-11  8:58   ` De Lara Guarch, Pablo
2018-05-11 10:13   ` De Lara Guarch, Pablo
2018-05-11  1:45 ` [dpdk-dev] [PATCH v4 03/18] bus/pci: replace strncpy dangerous code Andy Green
2018-05-11  8:17   ` De Lara Guarch, Pablo
2018-05-11  1:45 ` [dpdk-dev] [PATCH v4 04/18] bus/dpaa: solve inconsistent struct alignment Andy Green
2018-05-11  8:26   ` De Lara Guarch, Pablo
2018-05-11  1:45 ` [dpdk-dev] [PATCH v4 05/18] net/axgbe: solve broken eeprom string comp Andy Green
2018-05-11 10:09   ` De Lara Guarch, Pablo
2018-05-11  1:45 ` [dpdk-dev] [PATCH v4 06/18] net/nfp/nfpcore: solve strncpy misuse Andy Green
2018-05-11 10:26   ` De Lara Guarch, Pablo
2018-05-11  1:45 ` [dpdk-dev] [PATCH v4 07/18] net/nfp/nfpcore: off-by-one and no NUL on strncpy use Andy Green
2018-05-11 10:33   ` De Lara Guarch, Pablo
2018-05-12  1:17     ` Andy Green
2018-05-11  1:45 ` [dpdk-dev] [PATCH v4 08/18] net/nfp: don't memcpy out of source range Andy Green
2018-05-11 10:36   ` De Lara Guarch, Pablo
2018-05-11  1:46 ` [dpdk-dev] [PATCH v4 09/18] net/qede: strncpy length constant and NUL Andy Green
2018-05-11 10:43   ` De Lara Guarch, Pablo
2018-05-11 10:48     ` Andy Green
2018-05-11 12:48       ` De Lara Guarch, Pablo
2018-05-11 13:38         ` Andy Green
2018-05-11 15:14           ` De Lara Guarch, Pablo
2018-05-11 17:13         ` Shaikh, Shahed
2018-05-11  1:46 ` [dpdk-dev] [PATCH v4 10/18] net/qede: solve broken strncpy Andy Green
2018-05-11 10:47   ` De Lara Guarch, Pablo
2018-05-11  1:46 ` [dpdk-dev] [PATCH v4 11/18] net/sfc: correct strncpy length Andy Green
2018-05-11  8:11   ` Andrew Rybchenko
2018-05-11 10:51   ` De Lara Guarch, Pablo
2018-05-12  1:21     ` Andy Green
2018-05-11  1:46 ` [dpdk-dev] [PATCH v4 12/18] net/sfc: solve strncpy size and NUL Andy Green
2018-05-11  8:13   ` Andrew Rybchenko
2018-05-11 10:55   ` De Lara Guarch, Pablo
2018-05-12  1:24     ` Andy Green
2018-05-11  1:46 ` [dpdk-dev] [PATCH v4 13/18] net/vdev_netvsc: readlink inputs cannot be aliased Andy Green
2018-05-11 15:39   ` De Lara Guarch, Pablo
2018-05-11  1:46 ` [dpdk-dev] [PATCH v4 14/18] net/vdev_netvsc: 3 x strncpy misuse Andy Green
2018-05-11 10:58   ` De Lara Guarch, Pablo
2018-05-11  1:46 ` [dpdk-dev] [PATCH v4 15/18] app: can't find include Andy Green
2018-05-11 11:04   ` De Lara Guarch, Pablo
2018-05-11 11:12     ` Andy Green
2018-05-11 13:20       ` De Lara Guarch, Pablo
2018-05-12  0:52         ` Andy Green
2018-05-11  1:46 ` [dpdk-dev] [PATCH v4 16/18] app/proc-info: sprintf overrun bug Andy Green
2018-05-11 12:26   ` De Lara Guarch, Pablo
2018-05-12  1:33     ` Andy Green [this message]
2018-05-11  1:46 ` [dpdk-dev] [PATCH v4 17/18] app/test-bbdev: strcpy ok for allocated string Andy Green
2018-05-11 12:55   ` De Lara Guarch, Pablo
2018-05-11  1:46 ` [dpdk-dev] [PATCH v4 18/18] " Andy Green
2018-05-11 13:02   ` De Lara Guarch, Pablo
2018-05-12  1:39     ` Andy Green
2018-05-11 11:14 ` [dpdk-dev] [PATCH v4 00/18] Fix default build on gcc8.0.1 Neil Horman

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