[PATCH 1/2] debugfs: be more robust at handling improper input in debugfs_lookup()

[PATCH 1/2] debugfs: be more robust at handling improper input in debugfs_lookup()

[Greg Kroah-Hartman]

debugfs_lookup() doesn't like it if it is passed an illegal name
pointer, or if the filesystem isn't even initialized yet.  If either of
these happen, it will crash the system, so fix it up by properly testing
for valid input and that we are up and running before trying to find a
file in the filesystem.

Reported-by: Michael Walle <michael@walle.cc>
Tested-by: Michael Walle <michael@walle.cc>
Tested-by: Marc Zyngier <maz@kernel.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/debugfs/inode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 2fcf66473436..bbeb563cbe78 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -297,7 +297,7 @@ struct dentry *debugfs_lookup(const char *name, struct dentry *parent)
 {
 	struct dentry *dentry;
 
-	if (IS_ERR(parent))
+	if (!debugfs_initialized() || IS_ERR_OR_NULL(name) || IS_ERR(parent))
 		return NULL;
 
 	if (!parent)
-- 
2.30.1

[PATCH 2/2] debugfs: do not attempt to create a new file before the filesystem is initalized

[Greg Kroah-Hartman]

Some subsystems want to add debugfs files at early boot, way before
debugfs is initialized.  This seems to work somehow as the vfs layer
will not allow it to happen, but let's be explicit and test to ensure we
are properly up and running before allowing files to be created.

Reported-by: Michael Walle <michael@walle.cc>
Reported-by: Marc Zyngier <maz@kernel.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/debugfs/inode.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index bbeb563cbe78..86c7f0489620 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -318,6 +318,9 @@ static struct dentry *start_creating(const char *name, struct dentry *parent)
 	if (!(debugfs_allow & DEBUGFS_ALLOW_API))
 		return ERR_PTR(-EPERM);
 
+	if (!debugfs_initialized())
+		return ERR_PTR(-ENOENT);
+
 	pr_debug("creating file '%s'\n", name);
 
 	if (IS_ERR(parent))
-- 
2.30.1

[irqchip: irq/irqchip-next] debugfs: do not attempt to create a new file before the filesystem is initalized

[irqchip-bot for Greg Kroah-Hartman]

The following commit has been merged into the irq/irqchip-next branch of irqchip:

Commit-ID:     fb0757f54bc9259c4c67907fd97ca3ad109d3f6f
Gitweb:        https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms/fb0757f54bc9259c4c67907fd97ca3ad109d3f6f
Author:        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
AuthorDate:    Thu, 18 Feb 2021 11:08:18 +01:00
Committer:     Marc Zyngier <maz@kernel.org>
CommitterDate: Thu, 18 Feb 2021 11:39:18 

debugfs: do not attempt to create a new file before the filesystem is initalized

Some subsystems want to add debugfs files at early boot, way before
debugfs is initialized.  This seems to work somehow as the vfs layer
will not allow it to happen, but let's be explicit and test to ensure we
are properly up and running before allowing files to be created.

Reported-by: Michael Walle <michael@walle.cc>
Reported-by: Marc Zyngier <maz@kernel.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210218100818.3622317-2-gregkh@linuxfoundation.org
---
 fs/debugfs/inode.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index bbeb563..86c7f04 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -318,6 +318,9 @@ static struct dentry *start_creating(const char *name, struct dentry *parent)
 	if (!(debugfs_allow & DEBUGFS_ALLOW_API))
 		return ERR_PTR(-EPERM);
 
+	if (!debugfs_initialized())
+		return ERR_PTR(-ENOENT);
+
 	pr_debug("creating file '%s'\n", name);
 
 	if (IS_ERR(parent))

[irqchip: irq/irqchip-next] debugfs: be more robust at handling improper input in debugfs_lookup()

[irqchip-bot for Greg Kroah-Hartman]

The following commit has been merged into the irq/irqchip-next branch of irqchip:

Commit-ID:     2ad058730606cb68e75177ee7e330e1f94ab7b4b
Gitweb:        https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms/2ad058730606cb68e75177ee7e330e1f94ab7b4b
Author:        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
AuthorDate:    Thu, 18 Feb 2021 11:08:17 +01:00
Committer:     Marc Zyngier <maz@kernel.org>
CommitterDate: Thu, 18 Feb 2021 11:39:18 

debugfs: be more robust at handling improper input in debugfs_lookup()

debugfs_lookup() doesn't like it if it is passed an illegal name
pointer, or if the filesystem isn't even initialized yet.  If either of
these happen, it will crash the system, so fix it up by properly testing
for valid input and that we are up and running before trying to find a
file in the filesystem.

Reported-by: Michael Walle <michael@walle.cc>
Tested-by: Michael Walle <michael@walle.cc>
Tested-by: Marc Zyngier <maz@kernel.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210218100818.3622317-1-gregkh@linuxfoundation.org
---
 fs/debugfs/inode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 2fcf664..bbeb563 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -297,7 +297,7 @@ struct dentry *debugfs_lookup(const char *name, struct dentry *parent)
 {
 	struct dentry *dentry;
 
-	if (IS_ERR(parent))
+	if (!debugfs_initialized() || IS_ERR_OR_NULL(name) || IS_ERR(parent))
 		return NULL;
 
 	if (!parent)