linux-kernel - [PATCH 1/2] libnvdimm/security: 'security' attr never show 'overwrite' state

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Message-Id: <1595606959-8516-1-git-send-email-jane.chu@oracle.com>
Date:   Fri, 24 Jul 2020 10:09:18 -0600
From:   Jane Chu <jane.chu@...cle.com>
To:     dan.j.williams@...el.com, vishal.l.verma@...el.com,
        dave.jiang@...el.com, ira.weiny@...el.com, jmoyer@...hat.com,
        linux-nvdimm@...ts.01.org, linux-kernel@...r.kernel.org
Cc:     jane.chu@...cle.com
Subject: [PATCH 1/2] libnvdimm/security: 'security' attr never show 'overwrite' state

Since
commit d78c620a2e82 ("libnvdimm/security: Introduce a 'frozen' attribute"),
when issue
 # ndctl sanitize-dimm nmem0 --overwrite
then immediately check the 'security' attribute,
 # cat /sys/devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0012:00/ndbus0/nmem0/security
 unlocked
Actually the attribute stays 'unlocked' through out the entire overwrite
operation, never changed.  That's because 'nvdimm->sec.flags' is a bitmap
that has both bits set indicating 'overwrite' and 'unlocked'.
But security_show() checks the mutually exclusive bits before it checks
the 'overwrite' bit at last. The order should be reversed.

The commit also has a typo: in one occasion, 'nvdimm->sec.ext_state'
assignment is replaced with 'nvdimm->sec.flags' assignment for
the NVDIMM_MASTER type.

Cc: Dan Williams <dan.j.williams@...el.com>
Fixes: d78c620a2e82 ("libnvdimm/security: Introduce a 'frozen' attribute")
Signed-off-by: Jane Chu <jane.chu@...cle.com>
---
 drivers/nvdimm/dimm_devs.c | 4 ++--
 drivers/nvdimm/security.c  | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index b7b77e8..5d72026 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -363,14 +363,14 @@ __weak ssize_t security_show(struct device *dev,
 {
 	struct nvdimm *nvdimm = to_nvdimm(dev);
 
+	if (test_bit(NVDIMM_SECURITY_OVERWRITE, &nvdimm->sec.flags))
+		return sprintf(buf, "overwrite\n");
 	if (test_bit(NVDIMM_SECURITY_DISABLED, &nvdimm->sec.flags))
 		return sprintf(buf, "disabled\n");
 	if (test_bit(NVDIMM_SECURITY_UNLOCKED, &nvdimm->sec.flags))
 		return sprintf(buf, "unlocked\n");
 	if (test_bit(NVDIMM_SECURITY_LOCKED, &nvdimm->sec.flags))
 		return sprintf(buf, "locked\n");
-	if (test_bit(NVDIMM_SECURITY_OVERWRITE, &nvdimm->sec.flags))
-		return sprintf(buf, "overwrite\n");
 	return -ENOTTY;
 }
 
diff --git a/drivers/nvdimm/security.c b/drivers/nvdimm/security.c
index 4cef69b..8f3971c 100644
--- a/drivers/nvdimm/security.c
+++ b/drivers/nvdimm/security.c
@@ -457,7 +457,7 @@ void __nvdimm_security_overwrite_query(struct nvdimm *nvdimm)
 	clear_bit(NDD_WORK_PENDING, &nvdimm->flags);
 	put_device(&nvdimm->dev);
 	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
-	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_MASTER);
+	nvdimm->sec.ext_flags = nvdimm_security_flags(nvdimm, NVDIMM_MASTER);
 }
 
 void nvdimm_security_overwrite_query(struct work_struct *work)
-- 
1.8.3.1