Messages in this thread Patch in this message | | | Date | Fri, 26 Aug 2022 17:08:02 +0200 | Subject | [PATCH v5 39/44] x86: fs: kmsan: disable CONFIG_DCACHE_WORD_ACCESS | From | Alexander Potapenko <> |
| |
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.
Suggested-by: Andrey Konovalov <andreyknvl@gmail.com> Signed-off-by: Alexander Potapenko <glider@google.com> --- Link: https://linux-review.googlesource.com/id/I4c0073224ac2897cafb8c037362c49dda9cfa133 --- arch/x86/Kconfig | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 33f4d4baba079..697da8dae1418 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -128,7 +128,9 @@ 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 -- 2.37.2.672.g94769d06f0-goog
| |