Thomas Schauß <scha...@...> writes:
>
> Hello,
>
> we have exactly the same issue with unionfs and firefox. We did apply the
> patch posted above. The kernel oops occurs every time firefox is launched.
> Syslog shows the following:
>
> I tried to track down the problem and came to a similar conclusion as in the
> previous post:
>
> lower_inode = unionfs_lower_inode(inode); ==> lower_inode == NULL
>
> I tried to solve the problem by adding the following directly after the
> previous call:
>
> if (!lower_inode) {
> pr_info("unionfs: lower_inode NULL
> (name=%s)\n",dentry->d_name.name);
> err = -EINVAL;
> goto out;
> }
>
> This evaluation became true occasionally but the oops still occurred (still
> NULL pointer dereference in unionfs_setattr).
I had come to something similar but this was not enough. The second oops I got
was on the call of fput.
Here is the patch that avoid all oopses here on openoffice.org-voikko removal
(the binary called there indeed does several open/unlink/truncate for temporary
scripts)
Signed-off-by: Pascal Terjan <pter...@mandriva.com>
---
fs/unionfs/copyup.c | 2 +-
fs/unionfs/inode.c | 7 +++++++
2 files changed, 8 insertions(+), 1 deletions(-)
diff --git a/fs/unionfs/copyup.c b/fs/unionfs/copyup.c
index c43cc7f..9d7468f 100644
--- a/fs/unionfs/copyup.c
+++ b/fs/unionfs/copyup.c
@@ -498,7 +498,7 @@ out_unlink:
*/
vfs_unlink(new_lower_parent_dentry->d_inode, new_lower_dentry);
- if (copyup_file) {
+ if (copyup_file && *copyup_file) {
/* need to close the file */
fput(*copyup_file);
diff --git a/fs/unionfs/inode.c b/fs/unionfs/inode.c
index bd5a3b3..6b2f16f 100644
--- a/fs/unionfs/inode.c
+++ b/fs/unionfs/inode.c
@@ -918,11 +918,18 @@ static int unionfs_setattr(struct dentry *dentry, struct
iattr *ia)
lower_dentry = unionfs_lower_dentry(dentry);
if (!lower_dentry) { /* should never happen after above revalidate */
+ printk(KERN_ERR "unionfs: lower dentry NULL\n");
err = -EINVAL;
goto out;
}
lower_inode = unionfs_lower_inode(inode);
+ /* give up if no lower_inode */
+ if(!lower_inode) {
+ printk(KERN_ERR "unionfs: lower inode NULL\n");
+ err = -EINVAL;
+ goto out;
+ }
/* check if user has permission to change lower inode */
err = inode_change_ok(lower_inode, ia);
if (err)
--
1.6.2.5
_______________________________________________
unionfs mailing list: http://unionfs.filesystems.org/
unionfs@mail.fsl.cs.sunysb.edu
http://www.fsl.cs.sunysb.edu/mailman/listinfo/unionfs
