CVE-2022-49296

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

ceph: fix possible deadlock when holding Fwb to get inline_data

1, mount with wsync.

2, create a file with O_RDWR, and the request was sent to mds.0:

ceph_atomic_open()-->

ceph_mdsc_do_request(openc)

finish_open(file, dentry, ceph_open)-->

ceph_open()-->

ceph_init_file()-->

ceph_init_file_info()-->

ceph_uninline_data()-->

{

...

if (inline_version == 1 || /* initial version, no data */

inline_version == CEPH_INLINE_NONE)

goto out_unlock;

...

}

The inline_version will be 1, which is the initial version for the

new create file. And here the ci->i_inline_version will keep with 1,

it's buggy.

3, buffer write to the file immediately:

ceph_write_iter()-->

ceph_get_caps(file, need=Fw, want=Fb, ...);

generic_perform_write()-->

a_ops->write_b

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References