Alexander Potapenko 9ff078f5ba kmsan: do not wipe out origin when doing partial unpoisoning ... commit 2ef3cec44c upstream. As noticed by Brian, KMSAN should not be zeroing the origin when unpoisoning parts of a four-byte uninitialized value, e.g.: char a[4]; kmsan_unpoison_memory(a, 1); This led to false negatives, as certain poisoned values could receive zero origins, preventing those values from being reported. To fix the problem, check that kmsan_internal_set_shadow_origin() writes zero origins only to slots which have zero shadow. Link: https://lkml.kernel.org/r/20240528104807.738758-1-glider@google.com Fixes: f80be4571b ("kmsan: add KMSAN runtime core") Signed-off-by: Alexander Potapenko <glider@google.com> Reported-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Link: https://lore.kernel.org/lkml/20240524232804.1984355-1-bjohannesmeyer@gmail.com/T/ Reviewed-by: Marco Elver <elver@google.com> Tested-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2024-06-16 13:41:38 +02:00
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core.c	kmsan: do not wipe out origin when doing partial unpoisoning	2024-06-16 13:41:38 +02:00
hooks.c	mm: kmsan: handle alloc failures in kmsan_ioremap_page_range()	2023-04-26 14:28:41 +02:00
init.c	init: kmsan: call KMSAN initialization routines	2022-10-03 14:03:21 -07:00
instrumentation.c	x86: fortify: kmsan: fix KMSAN fortify builds	2022-10-28 13:37:23 -07:00
kmsan_test.c	kmsan: include linux/vmalloc.h	2023-01-04 11:28:59 +01:00
kmsan.h	kmsan: core: kmsan_in_runtime() should return true in NMI context	2022-11-08 15:57:24 -08:00
Makefile	kmsan: add tests for KMSAN	2022-10-03 14:03:22 -07:00
report.c	kmsan: add KMSAN runtime core	2022-10-03 14:03:19 -07:00
shadow.c	mm: kmsan: handle alloc failures in kmsan_vmap_pages_range_noflush()	2023-04-26 14:28:41 +02:00