Hi, On Sat, Sep 11, 2021 at 12:28:18PM +0200, Len Baker wrote: > As noted in the "Deprecated Interfaces, Language Features, Attributes, > and Conventions" documentation [1], size calculations (especially > multiplication) should not be performed in memory allocator (or similar) > function arguments due to the risk of them overflowing. This could lead > to values wrapping around and a smaller allocation being made than the > caller was expecting. Using those allocations could lead to linear > overflows of heap memory and other misbehaviors. > > So, use the struct_size() helper to do the arithmetic instead of the > argument "size + count * size" in the kzalloc() function. > > [1] https://www.kernel.org/doc/html/v5.14/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments > > Signed-off-by: Len Baker <len.baker@xxxxxxx> > --- > drivers/net/ethernet/microsoft/mana/hw_channel.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/net/ethernet/microsoft/mana/hw_channel.c b/drivers/net/ethernet/microsoft/mana/hw_channel.c > index 1a923fd99990..0efdc6c3c32a 100644 > --- a/drivers/net/ethernet/microsoft/mana/hw_channel.c > +++ b/drivers/net/ethernet/microsoft/mana/hw_channel.c > @@ -398,9 +398,7 @@ static int mana_hwc_alloc_dma_buf(struct hw_channel_context *hwc, u16 q_depth, > int err; > u16 i; > > - dma_buf = kzalloc(sizeof(*dma_buf) + > - q_depth * sizeof(struct hwc_work_request), > - GFP_KERNEL); > + dma_buf = kzalloc(struct_size(dma_buf, reqs, q_depth), GFP_KERNEL); > if (!dma_buf) > return -ENOMEM; > > -- > 2.25.1 > I have received a email from the linux-media subsystem telling that this patch is not applicable. The email is the following: Hello, The following patch (submitted by you) has been updated in Patchwork: * linux-media: net: mana: Prefer struct_size over open coded arithmetic - http://patchwork.linuxtv.org/project/linux-media/patch/20210911102818.3804-1-len.baker@xxxxxxx/ - for: Linux Media kernel patches was: New now: Not Applicable This email is a notification only - you do not need to respond. The question is: Why it is not applicable?. I have no received any bad comment and a "Reviewed-by:" tag from Haiyang Zhang. So, what is the reason for the "Not Applicable" state?. Regards, Len
