CVE-2021-47259
Description
In the Linux kernel, the following vulnerability has been resolved: NFS: Fix use-after-free in nfs4_init_client() KASAN reports a use-after-free when attempting to mount two different exports through two different NICs that belong to the same server. Olga was able to hit this with kernels starting somewhere between 5.7 and 5.10, but I traced the patch that introduced the clear_bit() call to 4.13. So something must have changed in the refcounting of the clp pointer to make this call to nfs_put_client() the very last one.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-47259
Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2021-47259.html
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 5.10.46-1 |
| debian | bullseye | fixed | 5.10.46-1 |
| debian | forky | fixed | 5.10.46-1 |
| debian | sid | fixed | 5.10.46-1 |
| debian | trixie | fixed | 5.10.46-1 |
References
Verify integrity in audit chain (admin only). AS-IS.