| 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-2022-48828: NFSD: Fix ia_size underflow |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| NFSD: Fix ia_size underflow |
| |
| iattr::ia_size is a loff_t, which is a signed 64-bit type. NFSv3 and |
| NFSv4 both define file size as an unsigned 64-bit type. Thus there |
| is a range of valid file size values an NFS client can send that is |
| already larger than Linux can handle. |
| |
| Currently decode_fattr4() dumps a full u64 value into ia_size. If |
| that value happens to be larger than S64_MAX, then ia_size |
| underflows. I'm about to fix up the NFSv3 behavior as well, so let's |
| catch the underflow in the common code path: nfsd_setattr(). |
| |
| The Linux kernel CVE team has assigned CVE-2022-48828 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.10.220 with commit 38d02ba22e43b6fc7d291cf724bc6e3b7be6626b |
| Fixed in 5.15.24 with commit 8e0ecaf7a7e57b30284d6b3289cc436100fadc48 |
| Fixed in 5.16.10 with commit da22ca1ad548429d7822011c54cfe210718e0aa7 |
| Fixed in 5.17 with commit e6faac3f58c7c4176b66f63def17a34232a17b0e |
| |
| 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-2022-48828 |
| 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: |
| fs/nfsd/vfs.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/38d02ba22e43b6fc7d291cf724bc6e3b7be6626b |
| https://git.kernel.org/stable/c/8e0ecaf7a7e57b30284d6b3289cc436100fadc48 |
| https://git.kernel.org/stable/c/da22ca1ad548429d7822011c54cfe210718e0aa7 |
| https://git.kernel.org/stable/c/e6faac3f58c7c4176b66f63def17a34232a17b0e |
