On Thu, Apr 02, 2026 at 03:48:20PM +0200, Marco Elver wrote: > On Thu, 2 Apr 2026 at 15:33, Dan Carpenter <[email protected]> wrote: > > > > Hi Marco, > > > > kernel test robot noticed the following build warnings: > > > > https://git-scm.com/docs/git-format-patch#_base_tree_information] > > > > url: > > https://github.com/intel-lab-lkp/linux/commits/Marco-Elver/slab-support-for-compiler-assisted-type-based-slab-cache-partitioning/20260401-035608 > > base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git > > mm-everything > > patch link: > > https://lore.kernel.org/r/20260331111240.153913-1-elver%40google.com > > patch subject: [PATCH v1] slab: support for compiler-assisted type-based > > slab cache partitioning > > config: um-randconfig-r072-20260401 > > compiler: gcc-14 (Debian 14.2.0-19) 14.2.0 > > smatch: v0.5.0-9004-gb810ac53 > > > > If you fix the issue in a separate patch/commit (i.e. not just a new > > version of > > the same patch/commit), kindly add following tags > > | Reported-by: kernel test robot <[email protected]> > > | Reported-by: Dan Carpenter <[email protected]> > > | Closes: https://lore.kernel.org/r/[email protected]/ > > > > New smatch warnings: > > drivers/misc/lkdtm/heap.c:118 lkdtm_READ_AFTER_FREE() warn: potential > > pointer math issue ('base' is a 32 bit pointer) > > drivers/misc/lkdtm/heap.c:169 lkdtm_KFENCE_READ_AFTER_FREE() warn: > > potential pointer math issue ('base' is a 32 bit pointer) > > How is this related to the patch I sent? Did the <linux/slab.h> change > force rechecking of all these files and it found latent issues? >
Oh, crud. It turns out that for this check Smatch allows integer_array[sizeof()]so long as we know that the index is within bounds. What happened is that your patch renamed the kmalloc() function so Smatch stopped knowing the size of the buffer. For these zero day bot warnings, the emails are automatically generated so I don't have any context outside what's in the email. I saw that Kees wrote the code, but I figured maybe you forwarded it or something. Sorry about that. regards, dan carpenter
