CVE-2021-47316
Description
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix NULL dereference in nfs3svc_encode_getaclres In error cases the dentry may be NULL. Before 20798dfe249a, the encoder also checked dentry and d_really_is_positive(dentry), but that looks like overkill to me--zero status should be enough to guarantee a positive dentry. This isn't the first time we've seen an error-case NULL dereference hidden in the initialization of a local variable in an xdr encoder. But I went back through the other recent rewrites and didn't spot any similar bugs.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No vendor mitigations ingested yet for this CVE. The mitigation-content worker queues fetches as references arrive — check back in a few minutes, or see the references list below.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 0 |
| debian | bullseye | fixed | 0 |
| debian | forky | fixed | 0 |
| debian | sid | fixed | 0 |
| debian | trixie | fixed | 0 |
| linux-kernel | affected | 5.13.4 |
References
- https://git.kernel.org/stable/c/650e6f383a6eb40f7c0a010982a74ab4b6893870
- https://git.kernel.org/stable/c/ab1016d39cc052064e32f25ad18ef8767a0ee3b8
- https://git.kernel.org/stable/c/e79057d15d96ef19de4de6d7e479bae3d58a2a8d
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html
- https://cert-portal.siemens.com/productcert/html/ssa-355557.html
- https://www.suse.com/security/cve/CVE-2021-47316.html
- https://security-tracker.debian.org/tracker/CVE-2021-47316
CWEs
CWE-476
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Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.