From: Greg Kroah-Hartman gregkh@linuxfoundation.org
[ Upstream commit 37ea7b630ae5cdea4e8ff381d9d23abfef5939e6 ]
Lots of callers of debugfs_lookup() were just checking NULL to see if the file/directory was found or not. By changing this in ff9fb72bc077 ("debugfs: return error values, not NULL") we caused some subsystems to easily crash.
Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL") Reported-by: syzbot+b382ba6a802a3d242790@syzkaller.appspotmail.com Reported-by: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Cc: Omar Sandoval osandov@fb.com Cc: Jens Axboe axboe@fb.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/debugfs/inode.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 0bbe2df9077c6..377aec4ddab64 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -252,8 +252,8 @@ MODULE_ALIAS_FS("debugfs"); * @parent: a pointer to the parent dentry of the file. * * This function will return a pointer to a dentry if it succeeds. If the file - * doesn't exist or an error occurs, %ERR_PTR(-ERROR) will be returned. The - * returned dentry must be passed to dput() when it is no longer needed. + * doesn't exist or an error occurs, %NULL will be returned. The returned + * dentry must be passed to dput() when it is no longer needed. * * If debugfs is not enabled in the kernel, the value -%ENODEV will be * returned. @@ -263,7 +263,7 @@ struct dentry *debugfs_lookup(const char *name, struct dentry *parent) struct dentry *dentry;
if (IS_ERR(parent)) - return parent; + return NULL;
if (!parent) parent = debugfs_mount->mnt_root; @@ -273,10 +273,10 @@ struct dentry *debugfs_lookup(const char *name, struct dentry *parent) inode_unlock(d_inode(parent));
if (IS_ERR(dentry)) - return dentry; + return NULL; if (!d_really_is_positive(dentry)) { dput(dentry); - return ERR_PTR(-EINVAL); + return NULL; } return dentry; }