| Message ID | 1454611679-17424-1-git-send-email-jacob.e.keller@intel.com |
|---|---|
| State | Accepted |
| Delegated to: | Jeff Kirsher |
| Headers | show |
-----Original Message----- From: Intel-wired-lan [mailto:intel-wired-lan-bounces@lists.osuosl.org] On Behalf Of Jacob Keller Sent: Thursday, February 4, 2016 10:48 AM To: Intel Wired LAN <intel-wired-lan@lists.osuosl.org> Subject: [Intel-wired-lan] [PATCH 1/6] fm10k: prevent null pointer dereference of msix_entries table According to the C standard dereferencing a variable before it is checked invokes undefined behavior, and thus compilers are free to assume the check for NULL isn't necessary. Prevent this by re-ordering the NULL check of msix_entries in fm10k_free_mbx_irq. Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> --- Tested-by: Krishneil Singh <Krishneil.k.singh@intel.com>
diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_pci.c b/drivers/net/ethernet/intel/fm10k/fm10k_pci.c index 6190a81b7c32..8c23fb3df572 100644 --- a/drivers/net/ethernet/intel/fm10k/fm10k_pci.c +++ b/drivers/net/ethernet/intel/fm10k/fm10k_pci.c @@ -1143,14 +1143,16 @@ static irqreturn_t fm10k_msix_mbx_pf(int __always_unused irq, void *data) void fm10k_mbx_free_irq(struct fm10k_intfc *interface) { - struct msix_entry *entry = &interface->msix_entries[FM10K_MBX_VECTOR]; struct fm10k_hw *hw = &interface->hw; + struct msix_entry *entry; int itr_reg; /* no mailbox IRQ to free if MSI-X is not enabled */ if (!interface->msix_entries) return; + entry = &interface->msix_entries[FM10K_MBX_VECTOR]; + /* disconnect the mailbox */ hw->mbx.ops.disconnect(hw, &hw->mbx);
According to the C standard dereferencing a variable before it is checked invokes undefined behavior, and thus compilers are free to assume the check for NULL isn't necessary. Prevent this by re-ordering the NULL check of msix_entries in fm10k_free_mbx_irq. Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> --- drivers/net/ethernet/intel/fm10k/fm10k_pci.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)