| Message ID | 20190529165343.GA2584@embeddedor (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ima: use struct_size() in kzalloc() | expand |
Hi all, Friendly ping: Who can take this, please? Thanks -- Gustavo On 5/29/19 11:53 AM, Gustavo A. R. Silva wrote: > One of the more common cases of allocation size calculations is finding > the size of a structure that has a zero-sized array at the end, along > with memory for some number of elements for that array. For example: > > struct foo { > int stuff; > struct boo entry[]; > }; > > instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL); > > Instead of leaving these open-coded and prone to type mistakes, we can > now use the new struct_size() helper: > > instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL); > > This code was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > --- > security/integrity/ima/ima_template.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c > index b631b8bc7624..b945dff2ed14 100644 > --- a/security/integrity/ima/ima_template.c > +++ b/security/integrity/ima/ima_template.c > @@ -281,9 +281,8 @@ static int ima_restore_template_data(struct ima_template_desc *template_desc, > int ret = 0; > int i; > > - *entry = kzalloc(sizeof(**entry) + > - template_desc->num_fields * sizeof(struct ima_field_data), > - GFP_NOFS); > + *entry = kzalloc(struct_size(*entry, template_data, > + template_desc->num_fields), GFP_NOFS); > if (!*entry) > return -ENOMEM; > >
On Wed, 2019-08-28 at 13:29 -0500, Gustavo A. R. Silva wrote: > Hi all, > > Friendly ping: > > Who can take this, please? Thank you for the reminder. I'm just getting back from LSS and a very short vacation. I'll look at it shortly. Mimi
On 8/28/19 1:46 PM, Mimi Zohar wrote: > On Wed, 2019-08-28 at 13:29 -0500, Gustavo A. R. Silva wrote: >> Hi all, >> >> Friendly ping: >> >> Who can take this, please? > > Thank you for the reminder. I'm just getting back from LSS and a very > short vacation. I'll look at it shortly. > Thanks, Mimi. -- Gustavo
Hi Gustavo, On Wed, 2019-08-28 at 13:29 -0500, Gustavo A. R. Silva wrote: > On 5/29/19 11:53 AM, Gustavo A. R. Silva wrote: > > One of the more common cases of allocation size calculations is finding > > the size of a structure that has a zero-sized array at the end, along > > with memory for some number of elements for that array. For example: > > > > struct foo { > > int stuff; > > struct boo entry[]; > > }; > > > > instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL); > > > > Instead of leaving these open-coded and prone to type mistakes, we can > > now use the new struct_size() helper: > > > > instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL); > > > > This code was detected with the help of Coccinelle. > > > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > > --- > > security/integrity/ima/ima_template.c | 5 ++--- > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c > > index b631b8bc7624..b945dff2ed14 100644 > > --- a/security/integrity/ima/ima_template.c > > +++ b/security/integrity/ima/ima_template.c > > @@ -281,9 +281,8 @@ static int ima_restore_template_data(struct ima_template_desc *template_desc, > > int ret = 0; > > int i; > > > > - *entry = kzalloc(sizeof(**entry) + > > - template_desc->num_fields * sizeof(struct ima_field_data), > > - GFP_NOFS); > > + *entry = kzalloc(struct_size(*entry, template_data, > > + template_desc->num_fields), GFP_NOFS); > > if (!*entry) > > return -ENOMEM; > > > > The same usage exists in ima_api.c: ima_alloc_init_template(). Did you want to make the change there as well? thanks, Mimi
Hi Mimi, On 8/28/19 10:45 PM, Mimi Zohar wrote: > > The same usage exists in ima_api.c: ima_alloc_init_template(). Did > you want to make the change there as well? > Yep. I'll write a patch for that one too. Thanks -- Gustavo
diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c index b631b8bc7624..b945dff2ed14 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -281,9 +281,8 @@ static int ima_restore_template_data(struct ima_template_desc *template_desc, int ret = 0; int i; - *entry = kzalloc(sizeof(**entry) + - template_desc->num_fields * sizeof(struct ima_field_data), - GFP_NOFS); + *entry = kzalloc(struct_size(*entry, template_data, + template_desc->num_fields), GFP_NOFS); if (!*entry) return -ENOMEM;
One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct foo { int stuff; struct boo entry[]; }; instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- security/integrity/ima/ima_template.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)