From: Sagi Grimberg Date: Wed, 13 Jan 2021 21:56:57 +0000 (-0800) Subject: nvme-tcp: fix possible data corruption with bio merges X-Git-Tag: v5.4.91~23 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=c70f6e0ac9f9350cd8cf3fcc2e55c5daa776d653;p=thirdparty%2Fkernel%2Fstable.git nvme-tcp: fix possible data corruption with bio merges commit ca1ff67d0fb14f39cf0cc5102b1fbcc3b14f6fb9 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index a31c6e1f6063a..a554021e1ab92 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -186,7 +186,7 @@ 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); }