4.15-stable review patch. If anyone has any objections, please let me know.
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From: Douglas Gilbert dgilbert@interlog.com
commit 69e0927b3774563c19b5fb32e91d75edc147fb62 upstream.
During stress tests by syzkaller on the sg driver the block layer infrequently returns EINVAL. Closer inspection shows the block layer was trying to return ENOMEM (which is much more understandable) but for some reason overroad that useful error.
Patch below does not show this (unchanged) line: ret =__blk_rq_map_user_iov(rq, map_data, &i, gfp_mask, copy); That 'ret' was being overridden when that function failed.
Signed-off-by: Douglas Gilbert dgilbert@interlog.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- block/blk-map.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/block/blk-map.c +++ b/block/blk-map.c @@ -119,7 +119,7 @@ int blk_rq_map_user_iov(struct request_q unsigned long align = q->dma_pad_mask | queue_dma_alignment(q); struct bio *bio = NULL; struct iov_iter i; - int ret; + int ret = -EINVAL;
if (!iter_is_iovec(iter)) goto fail; @@ -148,7 +148,7 @@ unmap_rq: __blk_rq_unmap_user(bio); fail: rq->bio = NULL; - return -EINVAL; + return ret; } EXPORT_SYMBOL(blk_rq_map_user_iov);