From b1ad377bbaf7dc8141f7b43c3a8013bff03ca0bf Mon Sep 17 00:00:00 2001 From: Michal Schmidt Date: Wed, 11 Oct 2023 16:33:32 -0700 Subject: [PATCH] i40e: prevent crash on probe if hw registers have invalid values commit fc6f716a5069180c40a8c9b63631e97da34f64a3 upstream. The hardware provides the indexes of the first and the last available queue and VF. From the indexes, the driver calculates the numbers of queues and VFs. In theory, a faulty device might say the last index is smaller than the first index. In that case, the driver's calculation would underflow, it would attempt to write to non-existent registers outside of the ioremapped range and crash. I ran into this not by having a faulty device, but by an operator error. I accidentally ran a QE test meant for i40e devices on an ice device. The test used 'echo i40e > /sys/...ice PCI device.../driver_override', bound the driver to the device and crashed in one of the wr32 calls in i40e_clear_hw. Add checks to prevent underflows in the calculations of num_queues and num_vfs. With this fix, the wrong device probing reports errors and returns a failure without crashing. Fixes: 838d41d92a90 ("i40e: clear all queues and interrupts") Signed-off-by: Michal Schmidt Reviewed-by: Simon Horman Tested-by: Pucha Himasekhar Reddy (A Contingent worker at Intel) Link: https://lore.kernel.org/r/20231011233334.336092-2-jacob.e.keller@intel.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/intel/i40e/i40e_common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_common.c b/drivers/net/ethernet/intel/i40e/i40e_common.c index 6475f78e85f6..a3709c4fc65d 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_common.c +++ b/drivers/net/ethernet/intel/i40e/i40e_common.c @@ -1341,7 +1341,7 @@ void i40e_clear_hw(struct i40e_hw *hw) I40E_PFLAN_QALLOC_FIRSTQ_SHIFT; j = (val & I40E_PFLAN_QALLOC_LASTQ_MASK) >> I40E_PFLAN_QALLOC_LASTQ_SHIFT; - if (val & I40E_PFLAN_QALLOC_VALID_MASK) + if (val & I40E_PFLAN_QALLOC_VALID_MASK && j >= base_queue) num_queues = (j - base_queue) + 1; else num_queues = 0; @@ -1351,7 +1351,7 @@ void i40e_clear_hw(struct i40e_hw *hw) I40E_PF_VT_PFALLOC_FIRSTVF_SHIFT; j = (val & I40E_PF_VT_PFALLOC_LASTVF_MASK) >> I40E_PF_VT_PFALLOC_LASTVF_SHIFT; - if (val & I40E_PF_VT_PFALLOC_VALID_MASK) + if (val & I40E_PF_VT_PFALLOC_VALID_MASK && j >= i) num_vfs = (j - i) + 1; else num_vfs = 0;