cifs: fix use after free in cifs_smb3_do_mount()

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Ronnie Sahlberg 2020-12-16 08:51:33 +10:00 committed by Steve French
parent 0c2b5f7ce5
commit 6cf5abbfa8

View file

@ -854,12 +854,14 @@ cifs_smb3_do_mount(struct file_system_type *fs_type,
if (IS_ERR(sb)) {
root = ERR_CAST(sb);
cifs_umount(cifs_sb);
cifs_sb = NULL;
goto out;
}
if (sb->s_root) {
cifs_dbg(FYI, "Use existing superblock\n");
cifs_umount(cifs_sb);
cifs_sb = NULL;
} else {
rc = cifs_read_super(sb);
if (rc) {
@ -870,7 +872,7 @@ cifs_smb3_do_mount(struct file_system_type *fs_type,
sb->s_flags |= SB_ACTIVE;
}
root = cifs_get_root(cifs_sb->ctx, sb);
root = cifs_get_root(cifs_sb ? cifs_sb->ctx : old_ctx, sb);
if (IS_ERR(root))
goto out_super;