From: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx> [ 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@xxxxxxxxxxxxx> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx> Fixes: 44144185951a0f ("hv_netvsc: Add validation for untrusted Hyper-V values") Reviewed-by: Jesse Brandeburg <jesse.brandeburg@xxxxxxxxx> Link: https://lore.kernel.org/r/20210203113602.558916-1-parri.andrea@xxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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