lkml.org 
[lkml]   [2019]   [Dec]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.4 15/80] block: fix "check bi_size overflow before merge"
Date
From: Andreas Gruenbacher <agruenba@redhat.com>

commit cc90bc68422318eb8e75b15cd74bc8d538a7df29 upstream.

This partially reverts commit e3a5d8e386c3fb973fa75f2403622a8f3640ec06.

Commit e3a5d8e386c3 ("check bi_size overflow before merge") adds a bio_full
check to __bio_try_merge_page. This will cause __bio_try_merge_page to fail
when the last bi_io_vec has been reached. Instead, what we want here is only
the bi_size overflow check.

Fixes: e3a5d8e386c3 ("block: check bi_size overflow before merge")
Cc: stable@vger.kernel.org # v5.4+
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
block/bio.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/block/bio.c
+++ b/block/bio.c
@@ -751,10 +751,12 @@ bool __bio_try_merge_page(struct bio *bi
if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
return false;

- if (bio->bi_vcnt > 0 && !bio_full(bio, len)) {
+ if (bio->bi_vcnt > 0) {
struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];

if (page_is_mergeable(bv, page, len, off, same_page)) {
+ if (bio->bi_iter.bi_size > UINT_MAX - len)
+ return false;
bv->bv_len += len;
bio->bi_iter.bi_size += len;
return true;

\
 
 \ /
  Last update: 2019-12-19 19:54    [W:0.281 / U:3.172 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site