From: Sagi Grimberg Date: Wed, 3 Feb 2021 09:20:25 +0000 (-0800) Subject: nvmet-tcp: fix out-of-bounds access when receiving multiple h2cdata PDUs X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=cb8563f5c735a042ea2dd7df1ad55ae06d63ffeb;p=linux.git 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 --- diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c index dc1f0f6471896..aacf06f0b4312 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,