From: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> stable inclusion from stable-v5.10.97 commit 4d3fcfe8464838b3920bc2b939d888e0b792934e bugzilla: https://gitee.com/openeuler/kernel/issues/I55O0O Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 5aac9108a180fc06e28d4e7fb00247ce603b72ee upstream. There will be BUG_ON() triggered in include/linux/skbuff.h leading to intermittent kernel panic, when the skb length underflow is detected. Fix this by dropping the packet if such length underflows are seen because of inconsistencies in the hardware descriptors. Fixes: 622c36f143fc ("amd-xgbe: Fix jumbo MTU processing on newer hardware") Suggested-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20220127092003.2812745-1-Shyam-sundar.S-k@amd.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yu Liao <liaoyu15@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- drivers/net/ethernet/amd/xgbe/xgbe-drv.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c index 66e71fa50687..a816b30bca04 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c @@ -2559,6 +2559,14 @@ static int xgbe_rx_poll(struct xgbe_channel *channel, int budget) buf2_len = xgbe_rx_buf2_len(rdata, packet, len); len += buf2_len; + if (buf2_len > rdata->rx.buf.dma_len) { + /* Hardware inconsistency within the descriptors + * that has resulted in a length underflow. + */ + error = 1; + goto skip_data; + } + if (!skb) { skb = xgbe_create_skb(pdata, napi, rdata, buf1_len); @@ -2588,8 +2596,10 @@ static int xgbe_rx_poll(struct xgbe_channel *channel, int budget) if (!last || context_next) goto read_again; - if (!skb) + if (!skb || error) { + dev_kfree_skb(skb); goto next_packet; + } /* Be sure we don't exceed the configured MTU */ max_len = netdev->mtu + ETH_HLEN; -- 2.20.1