| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-45004: KEYS: trusted: dcp: fix leak of blob encryption key |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| KEYS: trusted: dcp: fix leak of blob encryption key |
| |
| Trusted keys unseal the key blob on load, but keep the sealed payload in |
| the blob field so that every subsequent read (export) will simply |
| convert this field to hex and send it to userspace. |
| |
| With DCP-based trusted keys, we decrypt the blob encryption key (BEK) |
| in the Kernel due hardware limitations and then decrypt the blob payload. |
| BEK decryption is done in-place which means that the trusted key blob |
| field is modified and it consequently holds the BEK in plain text. |
| Every subsequent read of that key thus send the plain text BEK instead |
| of the encrypted BEK to userspace. |
| |
| This issue only occurs when importing a trusted DCP-based key and |
| then exporting it again. This should rarely happen as the common use cases |
| are to either create a new trusted key and export it, or import a key |
| blob and then just use it without exporting it again. |
| |
| Fix this by performing BEK decryption and encryption in a dedicated |
| buffer. Further always wipe the plain text BEK buffer to prevent leaking |
| the key via uninitialized memory. |
| |
| The Linux kernel CVE team has assigned CVE-2024-45004 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.10 with commit 2e8a0f40a39cc253002f21c54e1b5b995e5ec510 and fixed in 6.10.7 with commit 9e3b266afcfe4294e84496f50f006f029d3100db |
| Issue introduced in 6.10 with commit 2e8a0f40a39cc253002f21c54e1b5b995e5ec510 and fixed in 6.11 with commit 0e28bf61a5f9ab30be3f3b4eafb8d097e39446bb |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-45004 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| security/keys/trusted-keys/trusted_dcp.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/9e3b266afcfe4294e84496f50f006f029d3100db |
| https://git.kernel.org/stable/c/0e28bf61a5f9ab30be3f3b4eafb8d097e39446bb |
