diff mbox

nfit: fix unchecked dereference in acpi_nfit_ctl

Message ID 153132901164.57269.12329347241228490231.stgit@djiang5-desk3.ch.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dave Jiang July 11, 2018, 5:10 p.m. UTC
Incremental patch to fix the unchecked dereference in acpi_nfit_ctl.
Reported by Dan Carpenter:

"acpi/nfit: fix cmd_rc for acpi_nfit_ctl to
always return a value" from Jun 28, 2018, leads to the following
Smatch complaint:

    drivers/acpi/nfit/core.c:578 acpi_nfit_ctl()
     warn: variable dereferenced before check 'cmd_rc' (see line 411)

drivers/acpi/nfit/core.c
   410
   411		*cmd_rc = -EINVAL;
                ^^^^^^^^^^^^^^^^^^
Patch adds unchecked dereference.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/acpi/nfit/core.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Dan Williams July 11, 2018, 5:14 p.m. UTC | #1
On Wed, Jul 11, 2018 at 10:10 AM, Dave Jiang <dave.jiang@intel.com> wrote:
> Incremental patch to fix the unchecked dereference in acpi_nfit_ctl.
> Reported by Dan Carpenter:
>
> "acpi/nfit: fix cmd_rc for acpi_nfit_ctl to
> always return a value" from Jun 28, 2018, leads to the following
> Smatch complaint:
>
>     drivers/acpi/nfit/core.c:578 acpi_nfit_ctl()
>      warn: variable dereferenced before check 'cmd_rc' (see line 411)
>
> drivers/acpi/nfit/core.c
>    410
>    411          *cmd_rc = -EINVAL;
>                 ^^^^^^^^^^^^^^^^^^
> Patch adds unchecked dereference.

Looks good, when committing I would add:

Fixes: c1985cefd844 ("acpi/nfit: fix cmd_rc for acpi_nfit_ctl to
always return a value")

...and in the pull request to Linus note that this was the result of
testing in -next so he knows why there is a fresh commit on the
branch, and that the rest of the commits have survived -next with no
issues.
diff mbox

Patch

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 2be8373153ed..0f47917b8ef1 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -408,7 +408,8 @@  int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 	const guid_t *guid;
 	int rc, i;
 
-	*cmd_rc = -EINVAL;
+	if (cmd_rc)
+		*cmd_rc = -EINVAL;
 	func = cmd;
 	if (cmd == ND_CMD_CALL) {
 		call_pkg = buf;
@@ -519,7 +520,8 @@  int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 		 * If we return an error (like elsewhere) then caller wouldn't
 		 * be able to rely upon data returned to make calculation.
 		 */
-		*cmd_rc = 0;
+		if (cmd_rc)
+			*cmd_rc = 0;
 		return 0;
 	}