From ca1ff67d0fb14f39cf0cc5102b1fbcc3b14f6fb9 Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Wed, 13 Jan 2021 13:56:57 -0800 Subject: [PATCH] nvme-tcp: fix possible data corruption with bio merges When a bio merges, we can get a request that spans multiple bios, and the overall request payload size is the sum of all bios. When we calculate how much we need to send from the existing bio (and bvec), we did not take into account the iov_iter byte count cap. Since multipage bvecs support, bvecs can split in the middle which means that when we account for the last bvec send we should also take the iov_iter byte count cap as it might be lower than the last bvec size. Reported-by: Hao Wang Fixes: 3f2304f8c6d6 ("nvme-tcp: add NVMe over TCP host driver") Tested-by: Hao Wang Signed-off-by: Sagi Grimberg Signed-off-by: Christoph Hellwig --- drivers/nvme/host/tcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index b2e0865785ef..216619926563 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -201,7 +201,7 @@ static inline size_t nvme_tcp_req_cur_offset(struct nvme_tcp_request *req) static inline size_t nvme_tcp_req_cur_length(struct nvme_tcp_request *req) { - return min_t(size_t, req->iter.bvec->bv_len - req->iter.iov_offset, + return min_t(size_t, iov_iter_single_seg_count(&req->iter), req->pdu_len - req->pdu_sent); }