KMSAN metadata for consequent physical pages may be inconsequent, therefore accessing such pages together may lead to metadata corruption. We disable merging pages in biovec to prevent such corruptions. Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> --- Link: https://linux-review.googlesource.com/id/Iece16041be5ee47904fbc98121b105e5be5fea5c --- block/blk.h | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/block/blk.h b/block/blk.h index ccde6e6f17360..e0c62a5d5639e 100644 --- a/block/blk.h +++ b/block/blk.h @@ -103,6 +103,13 @@ static inline bool biovec_phys_mergeable(struct request_queue *q, phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset; phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset; + /* + * Merging consequent physical pages may not work correctly under KMSAN + * if their metadata pages aren't consequent. Just disable merging. + */ + if (IS_ENABLED(CONFIG_KMSAN)) + return false; + if (addr1 + vec1->bv_len != addr2) return false; if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page)) -- 2.34.1.173.g76aa8bc2d0-goog
