KMSAN doesn't allow treating adjacent memory pages as such, if they were allocated by different alloc_pages() calls. The block layer however does so: adjacent pages end up being used together. To prevent this, make page_is_mergeable() return false under KMSAN. Suggested-by: Eric Biggers <ebiggers@xxxxxxxxxx> Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> --- v4: -- swap block: and kmsan: in the subject Link: https://linux-review.googlesource.com/id/Ie29cc2464c70032347c32ab2a22e1e7a0b37b905 --- block/bio.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/block/bio.c b/block/bio.c index 51c99f2c5c908..ce6b3c82159a6 100644 --- a/block/bio.c +++ b/block/bio.c @@ -867,6 +867,8 @@ static inline bool page_is_mergeable(const struct bio_vec *bv, return false; *same_page = ((vec_end_addr & PAGE_MASK) == page_addr); + if (!*same_page && IS_ENABLED(CONFIG_KMSAN)) + return false; if (*same_page) return true; return (bv->bv_page + bv_end / PAGE_SIZE) == (page + off / PAGE_SIZE); -- 2.37.0.rc0.161.g10f37bed90-goog
