Re: [dpdk-dev] [dpdk-stable] [PATCH] eal: fix dereference before null check

[Ferruh Yigit]

On 9/19/2020 11:34 AM, wangyunjian wrote:
From: Yunjian Wang <wangyunj...@huawei.com>
This patch fixes (dereference after null check) coverity issue.
The intr_handle may be a null pointer which led to this issue.

Coverity issue: 357695, 357751
Fixes: 05c4105738d8 ("trace: add interrupt tracepoints")
Cc: sta...@dpdk.org

Signed-off-by: Yunjian Wang <wangyunj...@huawei.com>
---
  lib/librte_eal/freebsd/eal_interrupts.c | 6 ++++--
  lib/librte_eal/linux/eal_interrupts.c   | 6 ++++--
  2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/lib/librte_eal/freebsd/eal_interrupts.c 
b/lib/librte_eal/freebsd/eal_interrupts.c
index 6d53d33c8..028ab457a 100644
--- a/lib/librte_eal/freebsd/eal_interrupts.c
+++ b/lib/librte_eal/freebsd/eal_interrupts.c
@@ -380,7 +380,8 @@ rte_intr_enable(const struct rte_intr_handle *intr_handle)
        }
  
  out:
-       rte_eal_trace_intr_enable(intr_handle, rc);
+       if (intr_handle)
+               rte_eal_trace_intr_enable(intr_handle, rc);
        return rc;
  }
  
@@ -418,7 +419,8 @@ rte_intr_disable(const struct rte_intr_handle *intr_handle)
                break;
        }
  out:
-       rte_eal_trace_intr_disable(intr_handle, rc);
+       if (intr_handle)
+               rte_eal_trace_intr_disable(intr_handle, rc);
        return rc;
  }
  
diff --git a/lib/librte_eal/linux/eal_interrupts.c b/lib/librte_eal/linux/eal_interrupts.c
index 13db5c4e8..e46443873 100644
--- a/lib/librte_eal/linux/eal_interrupts.c
+++ b/lib/librte_eal/linux/eal_interrupts.c
@@ -725,7 +725,8 @@ rte_intr_enable(const struct rte_intr_handle *intr_handle)
                break;
        }
  out:
-       rte_eal_trace_intr_enable(intr_handle, rc);
+       if (intr_handle)
+               rte_eal_trace_intr_enable(intr_handle, rc);
        return rc;

It looks like whole function requires 'intr_handle' to be not NULL, so what do 
you think add following at the very beginning of the function and remove other 
'intr_handle' NULL checks from function:

if (intr_handle == NULL)
        return -1;

  }
  
@@ -852,7 +853,8 @@ rte_intr_disable(const struct rte_intr_handle *intr_handle)
                break;
        }
  out:
-       rte_eal_trace_intr_disable(intr_handle, rc);
+       if (intr_handle)
+               rte_eal_trace_intr_disable(intr_handle, rc);
        return rc;
  }