Re: [PATCH] sysfs & dput.

[Patrick Mochel]

> there is another, small bug in sysfs. In sysfs_create_bin_file 
> dentry gets assigned the error value of the call to sysfs_create
> if the call failed. The subsequent call to dput will crash. The
> solution is to remove the assignment of the error to dentry.

Thanks for the catch; Andrew Morton also posted a patch yesterday. 
However, your patch drops the error value, and his adds another variable. 
The patch below should be equivalent (and fixes the same problem for 
directories, too). 

Please test it, if you get a chance. 

> blue skies,

Heh, not today. :)


Thanks,


	Pat


===== fs/sysfs/dir.c 1.11 vs edited =====
--- 1.11/fs/sysfs/dir.c	Fri Aug 29 14:17:37 2003
+++ edited/fs/sysfs/dir.c	Thu Sep 11 09:32:12 2003
@@ -32,12 +32,12 @@
 		int error = sysfs_create(dentry,
 					 S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO,
 					 init_dir);
+		dput(dentry);
 		if (!error) {
 			dentry->d_fsdata = k;
 			p->d_inode->i_nlink++;
 		} else
 			dentry = ERR_PTR(error);
-		dput(dentry);
 	}
 	up(&p->d_inode->i_sem);
 	return dentry;
===== fs/sysfs/file.c 1.11 vs edited =====
--- 1.11/fs/sysfs/file.c	Fri Aug 29 09:40:51 2003
+++ edited/fs/sysfs/file.c	Thu Sep 11 09:32:19 2003
@@ -353,12 +353,14 @@
 	down(&dir->d_inode->i_sem);
 	dentry = sysfs_get_dentry(dir,attr->name);
 	if (!IS_ERR(dentry)) {
-		error = sysfs_create(dentry,(attr->mode & S_IALLUGO) | S_IFREG,init_file);
+		error = sysfs_create(dentry,
+				     (attr->mode & S_IALLUGO) | S_IFREG,
+				     init_file);
+		dput(dentry);
 		if (!error)
 			dentry->d_fsdata = (void *)attr;
 		else
 			dentry = ERR_PTR(error);
-		dput(dentry);
 	} else
 		error = PTR_ERR(dentry);
 	up(&dir->d_inode->i_sem);

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/