[PATCH][V2] scsi: qedf: remove memset/memcpy to nfunc and use func instead

[Colin King]

From: Colin Ian King <colin.k...@canonical.com>

Currently the qedf_dbg_* family of functions can overrun the end
of the source string if it is less than the destination buffer
length because of the use of a fixed sized memcpy. Remove the
memset/memcpy calls to nfunc and just use func instead as it
is always a null terminated string.

Addresses-Coverity: ("Out-of-bounds access")
Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver 
framework.")
Signed-off-by: Colin Ian King <colin.k...@canonical.com>
---

V2: replace the V1 strscpy with just using func since this is always
    going to be a NUL terminated string. Thanks to Rasmus Villemoes for
    noticing that.

---
 drivers/scsi/qedf/qedf_dbg.c | 32 ++++++++------------------------
 1 file changed, 8 insertions(+), 24 deletions(-)

diff --git a/drivers/scsi/qedf/qedf_dbg.c b/drivers/scsi/qedf/qedf_dbg.c
index f2397ee9ba69..f7d170bffc82 100644
--- a/drivers/scsi/qedf/qedf_dbg.c
+++ b/drivers/scsi/qedf/qedf_dbg.c
@@ -15,10 +15,6 @@ qedf_dbg_err(struct qedf_dbg_ctx *qedf, const char *func, 
u32 line,
 {
        va_list va;
        struct va_format vaf;
-       char nfunc[32];
-
-       memset(nfunc, 0, sizeof(nfunc));
-       memcpy(nfunc, func, sizeof(nfunc) - 1);
 
        va_start(va, fmt);
 
@@ -27,9 +23,9 @@ qedf_dbg_err(struct qedf_dbg_ctx *qedf, const char *func, u32 
line,
 
        if (likely(qedf) && likely(qedf->pdev))
                pr_err("[%s]:[%s:%d]:%d: %pV", dev_name(&(qedf->pdev->dev)),
-                       nfunc, line, qedf->host_no, &vaf);
+                       func, line, qedf->host_no, &vaf);
        else
-               pr_err("[0000:00:00.0]:[%s:%d]: %pV", nfunc, line, &vaf);
+               pr_err("[0000:00:00.0]:[%s:%d]: %pV", func, line, &vaf);
 
        va_end(va);
 }
@@ -40,10 +36,6 @@ qedf_dbg_warn(struct qedf_dbg_ctx *qedf, const char *func, 
u32 line,
 {
        va_list va;
        struct va_format vaf;
-       char nfunc[32];
-
-       memset(nfunc, 0, sizeof(nfunc));
-       memcpy(nfunc, func, sizeof(nfunc) - 1);
 
        va_start(va, fmt);
 
@@ -55,9 +47,9 @@ qedf_dbg_warn(struct qedf_dbg_ctx *qedf, const char *func, 
u32 line,
 
        if (likely(qedf) && likely(qedf->pdev))
                pr_warn("[%s]:[%s:%d]:%d: %pV", dev_name(&(qedf->pdev->dev)),
-                       nfunc, line, qedf->host_no, &vaf);
+                       func, line, qedf->host_no, &vaf);
        else
-               pr_warn("[0000:00:00.0]:[%s:%d]: %pV", nfunc, line, &vaf);
+               pr_warn("[0000:00:00.0]:[%s:%d]: %pV", func, line, &vaf);
 
 ret:
        va_end(va);
@@ -69,10 +61,6 @@ qedf_dbg_notice(struct qedf_dbg_ctx *qedf, const char *func, 
u32 line,
 {
        va_list va;
        struct va_format vaf;
-       char nfunc[32];
-
-       memset(nfunc, 0, sizeof(nfunc));
-       memcpy(nfunc, func, sizeof(nfunc) - 1);
 
        va_start(va, fmt);
 
@@ -84,10 +72,10 @@ qedf_dbg_notice(struct qedf_dbg_ctx *qedf, const char 
*func, u32 line,
 
        if (likely(qedf) && likely(qedf->pdev))
                pr_notice("[%s]:[%s:%d]:%d: %pV",
-                         dev_name(&(qedf->pdev->dev)), nfunc, line,
+                         dev_name(&(qedf->pdev->dev)), func, line,
                          qedf->host_no, &vaf);
        else
-               pr_notice("[0000:00:00.0]:[%s:%d]: %pV", nfunc, line, &vaf);
+               pr_notice("[0000:00:00.0]:[%s:%d]: %pV", func, line, &vaf);
 
 ret:
        va_end(va);
@@ -99,10 +87,6 @@ qedf_dbg_info(struct qedf_dbg_ctx *qedf, const char *func, 
u32 line,
 {
        va_list va;
        struct va_format vaf;
-       char nfunc[32];
-
-       memset(nfunc, 0, sizeof(nfunc));
-       memcpy(nfunc, func, sizeof(nfunc) - 1);
 
        va_start(va, fmt);
 
@@ -114,9 +98,9 @@ qedf_dbg_info(struct qedf_dbg_ctx *qedf, const char *func, 
u32 line,
 
        if (likely(qedf) && likely(qedf->pdev))
                pr_info("[%s]:[%s:%d]:%d: %pV", dev_name(&(qedf->pdev->dev)),
-                       nfunc, line, qedf->host_no, &vaf);
+                       func, line, qedf->host_no, &vaf);
        else
-               pr_info("[0000:00:00.0]:[%s:%d]: %pV", nfunc, line, &vaf);
+               pr_info("[0000:00:00.0]:[%s:%d]: %pV", func, line, &vaf);
 
 ret:
        va_end(va);
-- 
2.20.1