On Wed, May 29, 2019 at 1:31 PM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> Hello Amir Goldstein,
>
> The patch 0e7f2cccb42a: "ovl: detect overlapping layers" from Apr 18,
> 2019, leads to the following static checker warning:
>
> fs/overlayfs/super.c:998 ovl_setup_trap()
> warn: passing a valid pointer to 'PTR_ERR'
>
> fs/overlayfs/super.c
> 991 static int ovl_setup_trap(struct super_block *sb, struct dentry *dir,
> 992 struct inode **ptrap, const char *name)
> 993 {
> 994 struct inode *trap;
> 995 int err;
> 996
> 997 trap = ovl_get_trap_inode(sb, dir);
> 998 err = PTR_ERR(trap);
> 999 if (IS_ERR(trap) && err == -ELOOP) {
> 1000 pr_err("overlayfs: conflicting %s path\n", name);
> 1001 return err;
> 1002 }
> 1003
> 1004 *ptrap = trap;
> 1005 return 0;
> 1006 }
>
> The warning message is wrong but the code is also wrong. The
> ovl_get_trap_inode() can return ERR_PTR(-ENOMEM) and that would lead to
> and Oops when we try to call iput() on it.
>
Right, thank you for spotting this!
Miklos,
Can you fold in this fix:
Thanks,
Amir.
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -996,8 +996,9 @@ static int ovl_setup_trap(struct super_block *sb,
struct dentry *dir,
trap = ovl_get_trap_inode(sb, dir);
err = PTR_ERR(trap);
- if (IS_ERR(trap) && err == -ELOOP) {
- pr_err("overlayfs: conflicting %s path\n", name);
+ if (IS_ERR(trap)) {
+ if (err == -ELOOP)
+ pr_err("overlayfs: conflicting %s path\n", name);
return err;
}
