| 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-2021-47259: NFS: Fix use-after-free in nfs4_init_client() |
| |
| 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. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47259 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.13 with commit 8dcbec6d20eb881ba368d0aebc3a8a678aebb1da and fixed in 4.14.237 with commit c7eab9e2d7b4e983ce280276fb920af649955897 |
| Issue introduced in 4.13 with commit 8dcbec6d20eb881ba368d0aebc3a8a678aebb1da and fixed in 4.19.195 with commit 42c10b0db064e45f5c5ae7019bbf2168ffab766c |
| Issue introduced in 4.13 with commit 8dcbec6d20eb881ba368d0aebc3a8a678aebb1da and fixed in 5.4.126 with commit 3e3c7ebbfac152d08be75c92802a64a1f6471a15 |
| Issue introduced in 4.13 with commit 8dcbec6d20eb881ba368d0aebc3a8a678aebb1da and fixed in 5.10.44 with commit c3b6cf64dfe4ef96e7341508d50d6998da7062c7 |
| Issue introduced in 4.13 with commit 8dcbec6d20eb881ba368d0aebc3a8a678aebb1da and fixed in 5.12.11 with commit 72651c6579a25317a90536181d311c663d0329ab |
| Issue introduced in 4.13 with commit 8dcbec6d20eb881ba368d0aebc3a8a678aebb1da and fixed in 5.13 with commit 476bdb04c501fc64bf3b8464ffddefc8dbe01577 |
| |
| 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-2021-47259 |
| 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/nfs/nfs4client.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/c7eab9e2d7b4e983ce280276fb920af649955897 |
| https://git.kernel.org/stable/c/42c10b0db064e45f5c5ae7019bbf2168ffab766c |
| https://git.kernel.org/stable/c/3e3c7ebbfac152d08be75c92802a64a1f6471a15 |
| https://git.kernel.org/stable/c/c3b6cf64dfe4ef96e7341508d50d6998da7062c7 |
| https://git.kernel.org/stable/c/72651c6579a25317a90536181d311c663d0329ab |
| https://git.kernel.org/stable/c/476bdb04c501fc64bf3b8464ffddefc8dbe01577 |
