The quilt patch titled
Subject: x86: fs: kmsan: disable CONFIG_DCACHE_WORD_ACCESS
has been removed from the -mm tree. Its filename was
x86-fs-kmsan-disable-config_dcache_word_access.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Alexander Potapenko <glider@xxxxxxxxxx>
Subject: x86: fs: kmsan: disable CONFIG_DCACHE_WORD_ACCESS
Date: Thu, 15 Sep 2022 17:04:12 +0200
dentry_string_cmp() calls read_word_at_a_time(), which might read
uninitialized bytes to optimize string comparisons. Disabling
CONFIG_DCACHE_WORD_ACCESS should prohibit this optimization, as well as
(probably) similar ones.
Link: https://lkml.kernel.org/r/20220915150417.722975-39-glider@xxxxxxxxxx
Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
Suggested-by: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Eric Biggers <ebiggers@xxxxxxxxxx>
Cc: Eric Biggers <ebiggers@xxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Petr Mladek <pmladek@xxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Vegard Nossum <vegard.nossum@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/Kconfig | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/arch/x86/Kconfig~x86-fs-kmsan-disable-config_dcache_word_access
+++ a/arch/x86/Kconfig
@@ -129,7 +129,9 @@ config X86
select CLKEVT_I8253
select CLOCKSOURCE_VALIDATE_LAST_CYCLE
select CLOCKSOURCE_WATCHDOG
- select DCACHE_WORD_ACCESS
+ # Word-size accesses may read uninitialized data past the trailing \0
+ # in strings and cause false KMSAN reports.
+ select DCACHE_WORD_ACCESS if !KMSAN
select DYNAMIC_SIGFRAME
select EDAC_ATOMIC_SCRUB
select EDAC_SUPPORT
_
Patches currently in -mm which might be from glider@xxxxxxxxxx are
