CIFS: Fix undefined behavior when mount fails

Fix double kfree() calls on the same pointers and cleanup mount code.

Reviewed-and-Tested-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This commit is contained in:
Pavel Shilovsky 2011-05-25 13:35:34 +04:00 committed by Steve French
parent 3c1105df69
commit b2e5cd33b5

View File

@ -104,29 +104,23 @@ cifs_sb_deactive(struct super_block *sb)
}
static int
cifs_read_super(struct super_block *sb, struct cifs_sb_info *cifs_sb,
void *data, struct smb_vol *volume_info, const char *devname,
int silent)
cifs_read_super(struct super_block *sb, struct smb_vol *volume_info,
const char *devname, int silent)
{
struct inode *inode;
struct cifs_sb_info *cifs_sb;
int rc = 0;
/* BB should we make this contingent on mount parm? */
sb->s_flags |= MS_NODIRATIME | MS_NOATIME;
sb->s_fs_info = cifs_sb;
cifs_sb = CIFS_SB(sb);
spin_lock_init(&cifs_sb->tlink_tree_lock);
cifs_sb->tlink_tree = RB_ROOT;
rc = bdi_setup_and_register(&cifs_sb->bdi, "cifs", BDI_CAP_MAP_COPY);
if (rc) {
kfree(cifs_sb);
if (rc)
return rc;
}
cifs_sb->bdi.ra_pages = default_backing_dev_info.ra_pages;
if (data)
cifs_sb->mountdata = data;
cifs_sb->bdi.ra_pages = default_backing_dev_info.ra_pages;
rc = cifs_mount(sb, cifs_sb, volume_info, devname);
@ -179,15 +173,7 @@ out_no_root:
cifs_umount(sb, cifs_sb);
out_mount_failed:
if (cifs_sb) {
if (cifs_sb->mountdata) {
kfree(cifs_sb->mountdata);
cifs_sb->mountdata = NULL;
}
unload_nls(cifs_sb->local_nls);
bdi_destroy(&cifs_sb->bdi);
kfree(cifs_sb);
}
bdi_destroy(&cifs_sb->bdi);
return rc;
}
@ -553,7 +539,6 @@ cifs_do_mount(struct file_system_type *fs_type,
struct cifs_sb_info *cifs_sb;
struct smb_vol *volume_info;
struct dentry *root;
char *copied_data = NULL;
cFYI(1, "Devname: %s flags: %d ", dev_name, flags);
@ -576,20 +561,23 @@ cifs_do_mount(struct file_system_type *fs_type,
goto out;
}
sb->s_flags = flags;
/*
* Copy mount params for use in submounts. Better to do
* the copy here and deal with the error before cleanup gets
* complicated post-mount.
*/
copied_data = kstrndup(data, PAGE_SIZE, GFP_KERNEL);
if (copied_data == NULL) {
cifs_sb->mountdata = kstrndup(data, PAGE_SIZE, GFP_KERNEL);
if (cifs_sb->mountdata == NULL) {
root = ERR_PTR(-ENOMEM);
goto err_out;
}
rc = cifs_read_super(sb, cifs_sb, copied_data, volume_info, dev_name,
sb->s_flags = flags;
/* BB should we make this contingent on mount parm? */
sb->s_flags |= MS_NODIRATIME | MS_NOATIME;
sb->s_fs_info = cifs_sb;
rc = cifs_read_super(sb, volume_info, dev_name,
flags & MS_SILENT ? 1 : 0);
if (rc) {
root = ERR_PTR(rc);
@ -604,6 +592,8 @@ out:
return root;
err_out:
kfree(cifs_sb->mountdata);
unload_nls(cifs_sb->local_nls);
kfree(cifs_sb);
deactivate_locked_super(sb);
cifs_cleanup_volume_info(&volume_info);