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authorKees Cook <keescook@chromium.org>2018-05-01 14:01:30 -0700
committerDavid S. Miller <davem@davemloft.net>2018-05-02 11:11:30 -0400
commit8ac60ffb9a83c8f0f6b3bab5c205d75a32914904 (patch)
tree2cf6169fe64f112c23cfd632c6c413f1b050aeb6 /drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
parent795d8098d32b6bef3d0821588cb6e4b1f369a7a4 (diff)
downloadop-kernel-dev-8ac60ffb9a83c8f0f6b3bab5c205d75a32914904.zip
op-kernel-dev-8ac60ffb9a83c8f0f6b3bab5c205d75a32914904.tar.gz
net: stmmac: Avoid VLA usage
In the quest to remove all stack VLAs from the kernel[1], this switches the "status" stack buffer to use the existing small (8) upper bound on how many queues can be checked for DMA, and adds a sanity-check just to make sure it doesn't operate under pathological conditions. [1] http://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Jose Abreu <joabreu@synopsys.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/stmicro/stmmac/stmmac_main.c')
-rw-r--r--drivers/net/ethernet/stmicro/stmmac/stmmac_main.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 0135fd3..b935478 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2022,7 +2022,11 @@ static void stmmac_dma_interrupt(struct stmmac_priv *priv)
tx_channel_count : rx_channel_count;
u32 chan;
bool poll_scheduled = false;
- int status[channels_to_check];
+ int status[max_t(u32, MTL_MAX_TX_QUEUES, MTL_MAX_RX_QUEUES)];
+
+ /* Make sure we never check beyond our status buffer. */
+ if (WARN_ON_ONCE(channels_to_check > ARRAY_SIZE(status)))
+ channels_to_check = ARRAY_SIZE(status);
/* Each DMA channel can be used for rx and tx simultaneously, yet
* napi_struct is embedded in struct stmmac_rx_queue rather than in a
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