6.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexander Potapenko <glider@xxxxxxxxxx> commit 90d1f14cbb9ddbfc532e2da13bf6e0ed8320e792 upstream. It turned out that KMSAN instruments READ_ONCE_NOCHECK(), resulting in false positive reports, because __no_sanitize_or_inline enforced inlining. Properly declare __no_sanitize_or_inline under __SANITIZE_MEMORY__, so that it does not __always_inline the annotated function. Link: https://lkml.kernel.org/r/20240426091622.3846771-1-glider@xxxxxxxxxx Fixes: 5de0ce85f5a4 ("kmsan: mark noinstr as __no_sanitize_memory") Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> Reported-by: syzbot+355c5bb8c1445c871ee8@xxxxxxxxxxxxxxxxxxxxxxxxx Link: https://lkml.kernel.org/r/000000000000826ac1061675b0e3@xxxxxxxxxx Cc: <stable@xxxxxxxxxxxxxxx> Reviewed-by: Marco Elver <elver@xxxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Miguel Ojeda <ojeda@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/linux/compiler_types.h | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -278,6 +278,17 @@ struct ftrace_likely_data { # define __no_kcsan #endif +#ifdef __SANITIZE_MEMORY__ +/* + * Similarly to KASAN and KCSAN, KMSAN loses function attributes of inlined + * functions, therefore disabling KMSAN checks also requires disabling inlining. + * + * __no_sanitize_or_inline effectively prevents KMSAN from reporting errors + * within the function and marks all its outputs as initialized. + */ +# define __no_sanitize_or_inline __no_kmsan_checks notrace __maybe_unused +#endif + #ifndef __no_sanitize_or_inline #define __no_sanitize_or_inline __always_inline #endif
