From: Alexander Potapenko glider@google.com
[ Upstream commit f630a5d0ca59a6e73b61e3f82c371dc230da99ff ]
KMSAN metadata for adjacent physical pages may not be adjacent, therefore accessing such pages together may lead to metadata corruption. We disable merging pages in biovec to prevent such corruptions.
Link: https://lkml.kernel.org/r/20220915150417.722975-28-glider@google.com Signed-off-by: Alexander Potapenko glider@google.com Cc: Alexander Viro viro@zeniv.linux.org.uk Cc: Alexei Starovoitov ast@kernel.org Cc: Andrey Konovalov andreyknvl@gmail.com Cc: Andrey Konovalov andreyknvl@google.com Cc: Andy Lutomirski luto@kernel.org Cc: Arnd Bergmann arnd@arndb.de Cc: Borislav Petkov bp@alien8.de Cc: Christoph Hellwig hch@lst.de Cc: Christoph Lameter cl@linux.com Cc: David Rientjes rientjes@google.com Cc: Dmitry Vyukov dvyukov@google.com Cc: Eric Biggers ebiggers@google.com Cc: Eric Biggers ebiggers@kernel.org Cc: Eric Dumazet edumazet@google.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Herbert Xu herbert@gondor.apana.org.au Cc: Ilya Leoshkevich iii@linux.ibm.com Cc: Ingo Molnar mingo@redhat.com Cc: Jens Axboe axboe@kernel.dk Cc: Joonsoo Kim iamjoonsoo.kim@lge.com Cc: Kees Cook keescook@chromium.org Cc: Marco Elver elver@google.com Cc: Mark Rutland mark.rutland@arm.com Cc: Matthew Wilcox willy@infradead.org Cc: Michael S. Tsirkin mst@redhat.com Cc: Pekka Enberg penberg@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Petr Mladek pmladek@suse.com Cc: Stephen Rothwell sfr@canb.auug.org.au Cc: Steven Rostedt rostedt@goodmis.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Vasily Gorbik gor@linux.ibm.com Cc: Vegard Nossum vegard.nossum@oracle.com Cc: Vlastimil Babka vbabka@suse.cz Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- block/blk.h | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/block/blk.h b/block/blk.h index aab72194d226..e833f606bf63 100644 --- a/block/blk.h +++ b/block/blk.h @@ -66,6 +66,13 @@ 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 adjacent physical pages may not work correctly under KMSAN + * if their metadata pages aren't adjacent. 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))