v3: - fix commit messages to properly reflect the direction of the overwrite - justify the less-than-word-size patch better - add Acks - move some Fixes up into the commit log as just references v2: https://lore.kernel.org/lkml/20201009195411.4018141-1-keescook@xxxxxxxxxxxx v1: https://lore.kernel.org/lkml/20201008233443.3335464-1-keescook@xxxxxxxxxxxx This fixes redzoning vs the freelist pointer (both for middle-position and very small caches). Both are "theoretical" fixes, in that I see no evidence of such small-sized caches actually be used in the kernel, but that's no reason to let the bugs continue to exist. :) Note on patch 2: Christopher NAKed it, but I actually think this is a reasonable thing to add -- the "too small" check is only made when built with CONFIG_DEBUG_VM, so it *is* actually possible for someone to trip over this directly, even if it would never make it into a released kernel. I see no reason to just leave this foot-gun in place, though, so we might as well just fix it too. (Which seems to be what Longman was similarly supporting, IIUC.) Anyway, if patch 2 stays NAKed, that's fine. It's entirely separable, and the other 2 can land. :) Thanks! -Kees Kees Cook (3): mm/slub: Clarify verification reporting mm/slub: Fix redzoning for small allocations mm/slub: Actually fix freelist pointer vs redzoning Documentation/vm/slub.rst | 10 +++++----- mm/slub.c | 36 +++++++++++++++--------------------- 2 files changed, 20 insertions(+), 26 deletions(-) -- 2.25.1
