On 2/18/2024 9:04 PM, Kees Cook wrote: > On Mon, Feb 27, 2023 at 12:28:43PM -0800, Jesse Brandeburg wrote: >> On 2/22/2023 5:42 PM, Jacob Keller wrote: >>> The mux_chip structure size is over allocated to additionally include both >>> the array of mux controllers as well as a device specific private area. >>> The controllers array is then pointed to by assigning mux_chip->mux to the >>> first block of extra memory, while the private area is extracted via >>> mux_chip_priv() and points to the area just after the controllers. >>> >>> The size of the mux_chip allocation uses direct multiplication and addition >>> rather than the <linux/overflow.h> helpers. In addition, the mux_chip->mux >>> struct member wastes space by having to store the pointer as part of the >>> structures. >>> >>> Convert struct mux_chip to use a flexible array member for the mux >>> controller array. Use struct_size() and size_add() to compute the size of >>> the structure while protecting against overflow. >>> >>> After converting the mux pointer, notice that two 4-byte holes remain in >>> the structure layout due to the alignment requirements for the dev >>> sub-structure and the ops pointer. >>> >>> These can be easily fixed through re-ordering the id field to the 4-byte >>> hole just after the controllers member. >> >> Looks good to me (just a driver dev, not a mux dev!). Also added >> linux-i2c mailing list and a couple others for more review. >> >> Reviewed-by: Jesse Brandeburg <jesse.brandeburg@xxxxxxxxx> >> >> related thread (cocci script) at [1] >> >> [1] >> https://lore.kernel.org/all/20230227202428.3657443-1-jacob.e.keller@xxxxxxxxx/ > > *thread necromancy* > > Can we land this? It's the last struct_size() instance that the above > Coccinelle script flags. > > Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> > I'm happy to send a v2 if we need. Thanks, Jake
