From 2f83fd8c2849a388082f30d755a75c1e67c4643b Mon Sep 17 00:00:00 2001 From: hujianyang Date: Tue, 6 Jan 2015 12:52:13 +0800 Subject: ovl: Fix kernel panic while mounting overlayfs The function ovl_fill_super() in recently multi-layer support version will incorrectly return 0 at error handling path and then cause kernel panic. This failure can be reproduced by mounting a overlayfs with upperdir and workdir in different mounts. And also, If the memory allocation of *lower_mnt* fail, this function may return an zero either. This patch fix this problem by setting *err* to proper error number before jumping to error handling path. Signed-off-by: hujianyang Signed-off-by: Miklos Szeredi --- fs/overlayfs/super.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 84f3144e1b33..6ca8ea8cb9b2 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -836,6 +836,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) if (err) goto out_put_upperpath; + err = -EINVAL; if (upperpath.mnt != workpath.mnt) { pr_err("overlayfs: workdir and upperdir must reside under the same mount\n"); goto out_put_workpath; @@ -894,12 +895,14 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) } } + err = -ENOMEM; ufs->lower_mnt = kcalloc(numlower, sizeof(struct vfsmount *), GFP_KERNEL); if (ufs->lower_mnt == NULL) goto out_put_workdir; for (i = 0; i < numlower; i++) { struct vfsmount *mnt = clone_private_mount(&stack[i]); + err = PTR_ERR(mnt); if (IS_ERR(mnt)) { pr_err("overlayfs: failed to clone lowerpath\n"); goto out_put_lower_mnt; -- cgit v1.2.3