From: Richard Weinberger <richard@nod.at>
Date: Sun, 8 Jul 2018 21:33:25 +0000 (+0200)
Subject: ubifs: xattr: Don't operate on deleted inodes
X-Git-Tag: MMI-QSB30.62-17~983^2~71^2~17
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8a23348d76a1e7716da6e76383281ac82fc071cf;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git

ubifs: xattr: Don't operate on deleted inodes

commit 11a6fc3dc743e22fb50f2196ec55bee5140d3c52 upstream.

xattr operations can race with unlink and the following assert triggers:
UBIFS assert failed in ubifs_jnl_change_xattr at 1606 (pid 6256)

Fix this by checking i_nlink before working on the host inode.

Cc: <stable@vger.kernel.org>
Fixes: 1e51764a3c2a ("UBIFS: add new flash file system")
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c
index c13eae819cbc..d47f16c0d582 100644
--- a/fs/ubifs/xattr.c
+++ b/fs/ubifs/xattr.c
@@ -152,6 +152,12 @@ static int create_xattr(struct ubifs_info *c, struct inode *host,
 	ui->data_len = size;
 
 	mutex_lock(&host_ui->ui_mutex);
+
+	if (!host->i_nlink) {
+		err = -ENOENT;
+		goto out_noent;
+	}
+
 	host->i_ctime = current_time(host);
 	host_ui->xattr_cnt += 1;
 	host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm));
@@ -183,6 +189,7 @@ out_cancel:
 	host_ui->xattr_size -= CALC_XATTR_BYTES(size);
 	host_ui->xattr_names -= fname_len(nm);
 	host_ui->flags &= ~UBIFS_CRYPT_FL;
+out_noent:
 	mutex_unlock(&host_ui->ui_mutex);
 out_free:
 	make_bad_inode(inode);
@@ -234,6 +241,12 @@ static int change_xattr(struct ubifs_info *c, struct inode *host,
 	mutex_unlock(&ui->ui_mutex);
 
 	mutex_lock(&host_ui->ui_mutex);
+
+	if (!host->i_nlink) {
+		err = -ENOENT;
+		goto out_noent;
+	}
+
 	host->i_ctime = current_time(host);
 	host_ui->xattr_size -= CALC_XATTR_BYTES(old_size);
 	host_ui->xattr_size += CALC_XATTR_BYTES(size);
@@ -255,6 +268,7 @@ static int change_xattr(struct ubifs_info *c, struct inode *host,
 out_cancel:
 	host_ui->xattr_size -= CALC_XATTR_BYTES(size);
 	host_ui->xattr_size += CALC_XATTR_BYTES(old_size);
+out_noent:
 	mutex_unlock(&host_ui->ui_mutex);
 	make_bad_inode(inode);
 out_free:
@@ -483,6 +497,12 @@ static int remove_xattr(struct ubifs_info *c, struct inode *host,
 		return err;
 
 	mutex_lock(&host_ui->ui_mutex);
+
+	if (!host->i_nlink) {
+		err = -ENOENT;
+		goto out_noent;
+	}
+
 	host->i_ctime = current_time(host);
 	host_ui->xattr_cnt -= 1;
 	host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm));
@@ -502,6 +522,7 @@ out_cancel:
 	host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm));
 	host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len);
 	host_ui->xattr_names += fname_len(nm);
+out_noent:
 	mutex_unlock(&host_ui->ui_mutex);
 	ubifs_release_budget(c, &req);
 	make_bad_inode(inode);
@@ -541,6 +562,9 @@ static int ubifs_xattr_remove(struct inode *host, const char *name)
 
 	ubifs_assert(inode_is_locked(host));
 
+	if (!host->i_nlink)
+		return -ENOENT;
+
 	if (fname_len(&nm) > UBIFS_MAX_NLEN)
 		return -ENAMETOOLONG;