path: root/fs/debugfs
diff options
authorOndrej Mosnacek <>2021-05-07 14:53:04 +0200
committerGreg Kroah-Hartman <>2021-05-18 18:05:59 +0200
commit5881fa8dc2de9697a89451f6518e8b3a796c09c6 (patch)
treeeccf4c734a67417eaad33fea91bd2750bce801b3 /fs/debugfs
parentd07f6ca923ea0927a1024dfccafc5b53b61cfecc (diff)
debugfs: fix security_locked_down() call for SELinux
When (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) is zero, then the SELinux implementation of the locked_down hook might report a denial even though the operation would actually be allowed. To fix this, make sure that security_locked_down() is called only when the return value will be taken into account (i.e. when changing one of the problematic attributes). Note: this was introduced by commit 5496197f9b08 ("debugfs: Restrict debugfs when the kernel is locked down"), but it didn't matter at that time, as the SELinux support came in later. Fixes: 59438b46471a ("security,lockdown,selinux: implement SELinux lockdown") Cc: stable <> Signed-off-by: Ondrej Mosnacek <> Link: Signed-off-by: Greg Kroah-Hartman <>
Diffstat (limited to 'fs/debugfs')
1 files changed, 6 insertions, 3 deletions
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 1d252164d97b..8129a430d789 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -45,10 +45,13 @@ static unsigned int debugfs_allow __ro_after_init = DEFAULT_DEBUGFS_ALLOW_BITS;
static int debugfs_setattr(struct user_namespace *mnt_userns,
struct dentry *dentry, struct iattr *ia)
- int ret = security_locked_down(LOCKDOWN_DEBUGFS);
+ int ret;
- if (ret && (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)))
- return ret;
+ if (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) {
+ ret = security_locked_down(LOCKDOWN_DEBUGFS);
+ if (ret)
+ return ret;
+ }
return simple_setattr(&init_user_ns, dentry, ia);