diff mbox series

[5.4,54/76] nvme-tcp: fix possible data corruption with bio merges

Message ID 20210118113343.566005687@linuxfoundation.org
State Superseded
Headers show
Series None | expand

Commit Message

Greg Kroah-Hartman Jan. 18, 2021, 11:34 a.m. UTC 
From: Sagi Grimberg <sagi@grimberg.me>

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 <pkuwangh@gmail.com>
Fixes: 3f2304f8c6d6 ("nvme-tcp: add NVMe over TCP host driver")
Tested-by: Hao Wang <pkuwangh@gmail.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/nvme/host/tcp.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -186,7 +186,7 @@  static inline size_t nvme_tcp_req_cur_of
 
 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);
 }