From cb8563f5c735a042ea2dd7df1ad55ae06d63ffeb Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Wed, 3 Feb 2021 01:20:25 -0800 Subject: nvmet-tcp: fix out-of-bounds access when receiving multiple h2cdata PDUs When the host sends multiple h2cdata PDUs, we keep track on the receive progress and calculate the scatterlist index and offsets. The issue is that sg_offset should only be kept for the first iov entry we map in the iovec as this is the difference between our cursor and the sg entry offset itself. In addition, the sg index was calculated wrong because we should not round up when dividing the command byte offset with PAG_SIZE. Fixes: 872d26a391da ("nvmet-tcp: add NVMe over TCP target driver") Reported-by: Narayan Ayalasomayajula Tested-by: Narayan Ayalasomayajula Signed-off-by: Sagi Grimberg Signed-off-by: Christoph Hellwig --- drivers/nvme/target/tcp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/nvme') diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c index dc1f0f647189..aacf06f0b431 100644 --- a/drivers/nvme/target/tcp.c +++ b/drivers/nvme/target/tcp.c @@ -305,7 +305,7 @@ static void nvmet_tcp_map_pdu_iovec(struct nvmet_tcp_cmd *cmd) length = cmd->pdu_len; cmd->nr_mapped = DIV_ROUND_UP(length, PAGE_SIZE); offset = cmd->rbytes_done; - cmd->sg_idx = DIV_ROUND_UP(offset, PAGE_SIZE); + cmd->sg_idx = offset / PAGE_SIZE; sg_offset = offset % PAGE_SIZE; sg = &cmd->req.sg[cmd->sg_idx]; @@ -318,6 +318,7 @@ static void nvmet_tcp_map_pdu_iovec(struct nvmet_tcp_cmd *cmd) length -= iov_len; sg = sg_next(sg); iov++; + sg_offset = 0; } iov_iter_kvec(&cmd->recv_msg.msg_iter, READ, cmd->iov, -- cgit v1.2.3-58-ga151