Hi Kees, On Sat, Sep 18, 2021 at 06:51:51AM -0700, Kees Cook wrote: > > > 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? Yes, my workflow is scripts/checkpatch.pl and then scripts/get_maintainer.pl before sending any patch :) Regards, Len > > -Kees
