On September 18, 2021 6:20:10 AM PDT, Len Baker <len.baker@xxxxxxx> wrote: >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?. That is the "Media" subsystem patch tracker. The patch appears to be for networking, so the Media tracker has marked it as "not applicable [to the media subsystem]". The CC list for this patch seems rather wide (media, dri). I would have expected only netdev. Were you using scripts/get_maintainer.pl for getting addresses? -Kees
