From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Smatch complains that if we hit an error (for example if the file is
immutable) then "range" has uninitialized stack data and we copy it to
the user.
I've re-written the error handling to avoid this problem and make it a
little cleaner as well.
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Jie Liu <jeff.liu@xxxxxxxxxx>
---
v2: check for argp earlier
diff --git a/fs/ocfs2/move_extents.c b/fs/ocfs2/move_extents.c
index 9f8dcad..8f3d3cb 100644
--- a/fs/ocfs2/move_extents.c
+++ b/fs/ocfs2/move_extents.c
@@ -1057,42 +1057,40 @@ int ocfs2_ioctl_move_extents(struct file *filp, void __user *argp)
struct inode *inode = file_inode(filp);
struct ocfs2_move_extents range;
- struct ocfs2_move_extents_context *context = NULL;
+ struct ocfs2_move_extents_context *context;
+
+ if (!argp)
+ return -EINVAL;
status = mnt_want_write_file(filp);
if (status)
return status;
if ((!S_ISREG(inode->i_mode)) || !(filp->f_mode & FMODE_WRITE))
- goto out;
+ goto out_drop;
if (inode->i_flags & (S_IMMUTABLE|S_APPEND)) {
status = -EPERM;
- goto out;
+ goto out_drop;
}
context = kzalloc(sizeof(struct ocfs2_move_extents_context), GFP_NOFS);
if (!context) {
status = -ENOMEM;
mlog_errno(status);
- goto out;
+ goto out_drop;
}
context->inode = inode;
context->file = filp;
- if (argp) {
- if (copy_from_user(&range, argp, sizeof(range))) {
- status = -EFAULT;
- goto out;
- }
- } else {
- status = -EINVAL;
- goto out;
+ if (copy_from_user(&range, argp, sizeof(range))) {
+ status = -EFAULT;
+ goto out_free;
}
if (range.me_start > i_size_read(inode))
- goto out;
+ goto out_free;
if (range.me_start + range.me_len > i_size_read(inode))
range.me_len = i_size_read(inode) - range.me_start;
@@ -1124,25 +1122,24 @@ int ocfs2_ioctl_move_extents(struct file *filp, void __user *argp)
status = ocfs2_validate_and_adjust_move_goal(inode, &range);
if (status)
- goto out;
+ goto out_copy;
}
status = ocfs2_move_extents(context);
if (status)
mlog_errno(status);
-out:
+out_copy:
/*
* movement/defragmentation may end up being partially completed,
* that's the reason why we need to return userspace the finished
* length and new_offset even if failure happens somewhere.
*/
- if (argp) {
- if (copy_to_user(argp, &range, sizeof(range)))
- status = -EFAULT;
- }
+ if (copy_to_user(argp, &range, sizeof(range)))
+ status = -EFAULT;
+out_free:
kfree(context);
-
+out_drop:
mnt_drop_write_file(filp);
return status;
--
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