From: Christoph Hellwig <hch@xxxxxx> From: Christoph Hellwig <hch@xxxxxx> Upstream commit: b90994c6ab62 ("block: fix bounce_clone_bio for passthrough bios") This is backport to stable 5.10. It fixes an issue reported by syzbot. Link: https://syzkaller.appspot.com/bug?id=a3416231e37024a75f2b95bd95db0d8ce8132a84 Now that bio_alloc_bioset does not fall back to kmalloc for a NULL bio_set, handle that case explicitly and simplify the calling conventions. Based on an earlier patch from Chaitanya Kulkarni. Fixes: 3175199ab0ac ("block: split bio_kmalloc from bio_alloc_bioset") Reported-by: syzbot+4f441e6ca0fcad141421@xxxxxxxxxxxxxxxxxxxxxxxxx Reported-by: Chaitanya Kulkarni <Chaitanya.Kulkarni@xxxxxxx> Signed-off-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Tadeusz Struk <tadeusz.struk@xxxxxxxxxx> --- block/bounce.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/block/bounce.c b/block/bounce.c index 162a6eee8999..4da429de78a2 100644 --- a/block/bounce.c +++ b/block/bounce.c @@ -214,8 +214,7 @@ static void bounce_end_io_read_isa(struct bio *bio) __bounce_end_io_read(bio, &isa_page_pool); } -static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask, - struct bio_set *bs) +static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask) { struct bvec_iter iter; struct bio_vec bv; @@ -242,8 +241,11 @@ static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask, * asking for trouble and would force extra work on * __bio_clone_fast() anyways. */ - - bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs); + if (bio_is_passthrough(bio_src)) + bio = bio_kmalloc(gfp_mask, bio_segments(bio_src)); + else + bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), + &bounce_bio_set); if (!bio) return NULL; bio->bi_disk = bio_src->bi_disk; @@ -294,7 +296,6 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, unsigned i = 0; bool bounce = false; int sectors = 0; - bool passthrough = bio_is_passthrough(*bio_orig); bio_for_each_segment(from, *bio_orig, iter) { if (i++ < BIO_MAX_PAGES) @@ -305,14 +306,14 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, if (!bounce) return; - if (!passthrough && sectors < bio_sectors(*bio_orig)) { + if (!bio_is_passthrough(*bio_orig) && + sectors < bio_sectors(*bio_orig)) { bio = bio_split(*bio_orig, sectors, GFP_NOIO, &bounce_bio_split); bio_chain(bio, *bio_orig); submit_bio_noacct(*bio_orig); *bio_orig = bio; } - bio = bounce_clone_bio(*bio_orig, GFP_NOIO, passthrough ? NULL : - &bounce_bio_set); + bio = bounce_clone_bio(*bio_orig, GFP_NOIO); /* * Bvec table can't be updated by bio_for_each_segment_all(), -- 2.36.1 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel