From: Jun Nie jun.nie@linaro.org
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=3613786cb88c93aa1c6a279b1df6a7b201347d0... 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 --- fs/ext4/xattr.c | 7 +++++++ 1 file changed, 7 insertions(+)
--- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -1438,6 +1438,13 @@ static struct inode *ext4_xattr_inode_cr 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.