CVE-2022-49407

/// Technical description

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

dlm: fix plock invalid read

This patch fixes an invalid read showed by KASAN. A unlock will allocate a

"struct plock_op" and a followed send_op() will append it to a global

send_list data structure. In some cases a followed dev_read() moves it

to recv_list and dev_write() will cast it to "struct plock_xop" and access

fields which are only available in those structures. At this point an

invalid read happens by accessing those fields.

To fix this issue the "callback" field is moved to "struct plock_op" to

indicate that a cast to "plock_xop" is allowed and does the additional

"plock_xop" handling if set.

Example of the KASAN output which showed the invalid read:

[ 2064.296453] ==================================================================

[ 2064.304852] BUG: KASAN: slab-out-of-bounds in dev_write+0x52b/0x5a0 [dlm]

[ 2064.306491] Read of size 8 at addr ffff88800ef227d8 by task dlm_controld/7484

[ 2064.308168]

[ 20

/// 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