Commit a92b67e7 authored Jan 03, 2023 by Jun Nie Committed by Greg Kroah-Hartman Mar 11, 2023

ext4: refuse to create ea block when umounted



commit f31173c19901a96bb2ebf6bcfec8a08df7095c91 upstream.

The ea block expansion need to access s_root while it is
already set as NULL when umount is triggered. Refuse this
request to avoid panic.

Reported-by:  <syzbot+2dacb8f015bf1420155f@syzkaller.appspotmail.com>
Link: https://syzkaller.appspot.com/bug?id=3613786cb88c93aa1c6a279b1df6a7b201347d08
Link: https://lore.kernel.org/r/20230103014517.495275-3-jun.nie@linaro.org


Cc: stable@kernel.org
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 3b28c799

fs/ext4/xattr.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -1432,6 +1432,13 @@ static struct inode ext4_xattr_inode_create(handle_t handle,
		uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) };
		int err;

		if (inode->i_sb->s_root == NULL) {
		ext4_warning(inode->i_sb,
		"refuse to create EA inode when umounting");
		WARN_ON(1);
		return ERR_PTR(-EINVAL);
		}

		/*
		* Let the next inode be the goal, so we try and allocate the EA inode
		* in the same group, or nearby one.