On Fri, Feb 13, 2015 at 06:11:02PM +0000, Ananyev, Konstantin wrote: > > > > -----Original Message----- > > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Neil Horman > > Sent: Friday, February 13, 2015 5:55 PM > > To: Olivier MATZ > > Cc: dev at dpdk.org > > Subject: Re: [dpdk-dev] [PATCH v6 04/19] eal: fix wrong strnlen() return > > value in 32bit icc > > > > On Fri, Feb 13, 2015 at 03:05:44PM +0100, Olivier MATZ wrote: > > > Hi Neil, > > > > > > On 02/13/2015 02:49 PM, Neil Horman wrote: > > > > On Fri, Feb 13, 2015 at 09:38:06AM +0800, Cunming Liang wrote: > > > >> The problem is that strnlen() here may return invalid value with 32bit > > > >> icc. > > > >> (actually it returns it?s second parameter,e.g: sysconf(_SC_ARG_MAX)). > > > >> It starts to manifest hwen max_len parameter is > 2M and using icc > > > >> ?m32 ?O2 (or above). > > > >> > > > >> Suggested-by: Konstantin Ananyev <konstantin.ananyev at intel.com> > > > >> Signed-off-by: Cunming Liang <cunming.liang at intel.com> > > > >> --- > > > >> v5 changes: > > > >> using strlen instead of strnlen. > > > >> > > > >> lib/librte_eal/common/eal_common_options.c | 6 +++--- > > > >> 1 file changed, 3 insertions(+), 3 deletions(-) > > > >> > > > >> diff --git a/lib/librte_eal/common/eal_common_options.c > > > >> b/lib/librte_eal/common/eal_common_options.c > > > >> index 178e303..9cf2faa 100644 > > > >> --- a/lib/librte_eal/common/eal_common_options.c > > > >> +++ b/lib/librte_eal/common/eal_common_options.c > > > >> @@ -167,7 +167,7 @@ eal_parse_coremask(const char *coremask) > > > >> if (coremask[0] == '0' && ((coremask[1] == 'x') > > > >> || (coremask[1] == 'X'))) > > > >> coremask += 2; > > > >> - i = strnlen(coremask, PATH_MAX); > > > >> + i = strlen(coremask); > > > > This is crash prone. If coremask is passed in without a trailing null > > > > pointer, > > > > strlen will return a huge value that can overrun the array. > > > > > > We discussed that in a previous thread: > > > http://dpdk.org/ml/archives/dev/2015-February/012552.html > > > > > > coremask is always a valid nul-terminated string as it comes from > > > argv[] table. > > > It is not a memory fragment that is controlled by a user, so I don't > > > think using strnlen() instead of strlen() would solve any issue. > > > > > Thats absolutely false, you can't in any way make that assertion. > > eal_parse_common_option is a public API call. > > Why do you consider is as public API? > It is declared in private librte_eal header file: > lib/librte_eal/common/eal_options.h > So yes, in theory it can be used by some other functions inside librte_eal. > But it shouldn't be visible outside librte_eal. > Konstantin > I apologize, I misread the Makefile. I thought I saw that it was symlinked as a publically accessible header file, but thats not the case. As such, it should be ok.
Acked-by: Neil Horman <nhorman at tuxdriver.com> > > An application can construct its > > own string to pass into the parser. The test applications all use the > > command > > line functions so its not a visible issue from the test apps, but you can't > > assume what the test apps do is what everyone will do. It would be one > > thing if > > you could make the parse_common_option function private, but with the > > current > > layout you can't so you have to be ready for garbage input. > > > > Neil > > > > > Regards, > > > Olivier > > >
