Messages in this thread | | | Date | Wed, 24 Aug 2011 19:12:05 +0800 | Subject | Re: [PATCH] mtd: check parts pointer before using it | From | Jason Liu <> |
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2011/8/24 Jamie Iles <jamie@jamieiles.com>: > Hi Jason, > > On Wed, Aug 24, 2011 at 06:53:01PM +0800, Jason Liu wrote: >> The code has the check for parts but it called after kmemdup, >> kmemdup(parts, sizeof(*parts) * nr_parts,...) >> if (!parts) >> return -ENOMEM >> >> In fact, we need check parts before safely using it. >> >> Signed-off-by: Jason Liu <jason.hui@linaro.org> >> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> >> Cc: Artem Bityutskiy <artem.bityutskiy@intel.com> >> >> --- >> This patch is based on git://git.infradead.org/users/dedekind/l2-mtd-2.6.git >> --- >> drivers/mtd/mtdcore.c | 4 +--- >> 1 files changed, 1 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c >> index 09bdbac..ce59ff5 100644 >> --- a/drivers/mtd/mtdcore.c >> +++ b/drivers/mtd/mtdcore.c >> @@ -465,12 +465,10 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char **types, >> struct mtd_partition *real_parts; >> >> err = parse_mtd_partitions(mtd, types, &real_parts, parser_data); >> - if (err <= 0 && nr_parts) { >> + if (err <= 0 && nr_parts && !parts) { > > I don't think this is right. Don't we want to check that parts is != > NULL? So > > if (err <= 0 && nr_parts && parts) > > instead? We don't want to kmemdup() NULL.
My bad, I type it error. Thanks for it.
> >> real_parts = kmemdup(parts, sizeof(*parts) * nr_parts, >> GFP_KERNEL); >> err = nr_parts; >> - if (!parts) >> - err = -ENOMEM; > > I think this hunk should be changed to: > > if (!real_parts) > err = -ENOMEM; > > and keep the check so that we're checking kmemdup()'s allocation is > successful.
Yes, correct. Thanks,
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