| From bippy-d175d3acf727 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-2021-47213: NFSD: Fix exposure in nfsd4_decode_bitmap() |
| Message-Id: <2024041005-CVE-2021-47213-c84f@gregkh> |
| Content-Length: 1987 |
| Lines: 57 |
| X-Developer-Signature: v=1; a=openpgp-sha256; l=2045; |
| i=gregkh@linuxfoundation.org; h=from:subject:message-id; |
| bh=ID2nPGGUOP0Qnw+Z7BAkS5MBqS9u3a0qdtcx+iy8Da8=; |
| b=owGbwMvMwCRo6H6F97bub03G02pJDGlij3RnpOZuSlLkmLuokmtLatGSG19cUtas379XYs069 |
| ofPQh/2dsSyMAgyMciKKbJ82cZzdH/FIUUvQ9vTMHNYmUCGMHBxCsBEHtQwzI9T4Jxx7oXcb66D |
| /LvnH1wbJmIoz8cwz4D513+OkN/zWT83lMu2Xj1jdeFbCgA= |
| X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; |
| fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| NFSD: Fix exposure in nfsd4_decode_bitmap() |
| |
| rtm@csail.mit.edu reports: |
| > nfsd4_decode_bitmap4() will write beyond bmval[bmlen-1] if the RPC |
| > directs it to do so. This can cause nfsd4_decode_state_protect4_a() |
| > to write client-supplied data beyond the end of |
| > nfsd4_exchange_id.spo_must_allow[] when called by |
| > nfsd4_decode_exchange_id(). |
| |
| Rewrite the loops so nfsd4_decode_bitmap() cannot iterate beyond |
| @bmlen. |
| |
| Reported by: rtm@csail.mit.edu |
| |
| The Linux kernel CVE team has assigned CVE-2021-47213 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.11 with commit d1c263a031e8 and fixed in 5.15.5 with commit 10c22d9519f3 |
| Issue introduced in 5.11 with commit d1c263a031e8 and fixed in 5.16 with commit c0019b7db1d7 |
| |
| 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-2021-47213 |
| 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/nfs4xdr.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/10c22d9519f3f5939de61a1500aa3a926b778d3a |
| https://git.kernel.org/stable/c/c0019b7db1d7ac62c711cda6b357a659d46428fe |
