[PATCH 5.10 064/104] hv_netvsc: Reset the RSC count if NVSP_STAT_FAIL in netvsc_receive()

Greg Kroah-Hartman
2021-02-15T15:40:30Z

From: Andrea Parri (Microsoft) <parri.andrea@gmail.com>

[ Upstream commit 12bc8dfb83b5292fe387b795210018b7632ee08b ]

Commit 44144185951a0f ("hv_netvsc: Add validation for untrusted Hyper-V
values") added validation to rndis_filter_receive_data() (and
rndis_filter_receive()) which introduced NVSP_STAT_FAIL-scenarios where
the count is not updated/reset. Fix this omission, and prevent similar
scenarios from occurring in the future.

Reported-by: Juan Vazquez <juvazq@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Fixes: 44144185951a0f ("hv_netvsc: Add validation for untrusted Hyper-V values")
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Link: https://lore.kernel.org/r/20210203113602.558916-1-parri.andrea@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/hyperv/netvsc.c | 5 ++++-
drivers/net/hyperv/rndis_filter.c | 2 --
2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 0c3de94b51787..6a7ab930ef70d 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -1253,8 +1253,11 @@ static int netvsc_receive(struct net_device *ndev,
ret = rndis_filter_receive(ndev, net_device,
nvchan, data, buflen);

- if (unlikely(ret != NVSP_STAT_SUCCESS))
+ if (unlikely(ret != NVSP_STAT_SUCCESS)) {
+ /* Drop incomplete packet */
+ nvchan->rsc.cnt = 0;
status = NVSP_STAT_FAIL;
+ }
}

enq_receive_complete(ndev, net_device, q_idx,
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index b22e47bcfeca1..90bc0008fa2fd 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -508,8 +508,6 @@ static int rndis_filter_receive_data(struct net_device *ndev,
return ret;

drop:
- /* Drop incomplete packet */
- nvchan->rsc.cnt = 0;
return NVSP_STAT_FAIL;
}

--
2.27.0