In the Linux kernel, the following vulnerability has been resolved: ext4: do not create EA inode under buffer lock ext4_xattr_set_entry() creates new EA inodes while holding buffer lock on the external xattr block. This is problematic as it nests all the allocation locking (which acquires locks on other buffers) under the buffer lock. This can even deadlock when the filesystem is corrupted and e.g. quota file is setup to contain xattr block as data block. Move the allocation of EA inode out of ext4_xattr_set_entry() into the callers.
https://git.kernel.org/stable/c/737fb7853acd5bc8984f6f42e4bfba3334be8ae1
https://git.kernel.org/stable/c/111103907234bffd0a34fba070ad9367de058752
https://git.kernel.org/stable/c/0a46ef234756dca04623b7591e8ebb3440622f0b
https://git.kernel.org/stable/c/0752e7fb549d90c33b4d4186f11cfd25a556d1dd