Date: Mon, 27 Dec 2021 00:57:08 GMT From: Rick Macklem <rmacklem@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 030acb63d9a8 - stable/13 - nfsd: Limit parsing of layout errors to maxcnt bytes Message-ID: <202112270057.1BR0v8dP069804@gitrepo.freebsd.org>
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The branch stable/13 has been updated by rmacklem: URL: https://cgit.FreeBSD.org/src/commit/?id=030acb63d9a86b9a7bd15b06e60699abfa8a0a2b commit 030acb63d9a86b9a7bd15b06e60699abfa8a0a2b Author: Rick Macklem <rmacklem@FreeBSD.org> AuthorDate: 2021-12-13 23:21:31 +0000 Commit: Rick Macklem <rmacklem@FreeBSD.org> CommitDate: 2021-12-27 00:53:50 +0000 nfsd: Limit parsing of layout errors to maxcnt bytes This patch decrements maxcnt by the appropriate number of bytes during parsing and checks to see if there is data remaining. If not, it just returns from nfsrv_flexlayouterr() without further processing. This prevents the tl pointer from running off the end of the error data pointed at by layp, if there are flaws in the data. PR: 260293 (cherry picked from commit c302f889e21f73746a3b0917df5246e639df1481) --- sys/fs/nfsserver/nfs_nfsdstate.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/sys/fs/nfsserver/nfs_nfsdstate.c b/sys/fs/nfsserver/nfs_nfsdstate.c index 67f615ecea7c..1d0884683904 100644 --- a/sys/fs/nfsserver/nfs_nfsdstate.c +++ b/sys/fs/nfsserver/nfs_nfsdstate.c @@ -7001,14 +7001,25 @@ nfsrv_flexlayouterr(struct nfsrv_descript *nd, uint32_t *layp, int maxcnt, char devid[NFSX_V4DEVICEID]; tl = layp; - cnt = fxdr_unsigned(int, *tl++); + maxcnt -= NFSX_UNSIGNED; + if (maxcnt > 0) + cnt = fxdr_unsigned(int, *tl++); + else + cnt = 0; NFSD_DEBUG(4, "flexlayouterr cnt=%d\n", cnt); for (i = 0; i < cnt; i++) { + maxcnt -= NFSX_STATEID + 2 * NFSX_HYPER + + NFSX_UNSIGNED; + if (maxcnt <= 0) + break; /* Skip offset, length and stateid for now. */ tl += (4 + NFSX_STATEID / NFSX_UNSIGNED); errcnt = fxdr_unsigned(int, *tl++); NFSD_DEBUG(4, "flexlayouterr errcnt=%d\n", errcnt); for (j = 0; j < errcnt; j++) { + maxcnt -= NFSX_V4DEVICEID + 2 * NFSX_UNSIGNED; + if (maxcnt < 0) + break; NFSBCOPY(tl, devid, NFSX_V4DEVICEID); tl += (NFSX_V4DEVICEID / NFSX_UNSIGNED); stat = fxdr_unsigned(int, *tl++);
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