4.14-stable review patch. If anyone has any objections, please let me know.
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From: Michal Schmidt mschmidt@redhat.com
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 mschmidt@redhat.com Reviewed-by: Simon Horman horms@kernel.org Tested-by: Pucha Himasekhar Reddy himasekharx.reddy.pucha@intel.com (A Contingent worker at Intel) Link: https://lore.kernel.org/r/20231011233334.336092-2-jacob.e.keller@intel.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/intel/i40e/i40e_common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/net/ethernet/intel/i40e/i40e_common.c +++ b/drivers/net/ethernet/intel/i40e/i40e_common.c @@ -1320,7 +1320,7 @@ 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; @@ -1330,7 +1330,7 @@ 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;