From nobody Tue Sep 29 15:55:49 2026 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4hvN7T3tsMz6tl36 for ; Tue, 29 Sep 2026 15:55:49 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "YR2" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4hvN7T2cflz4T8n for ; Tue, 29 Sep 2026 15:55:49 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1790697349; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=qNbmGDxR4H/6TaFo439lEgL32XObVC4te6WCkle8MIU=; b=R07NWP4NYGSj+uTkvnva0+tUWpW7cq0lIASE3ZxKyH+yrqJPG7k0SEaEYTB6hRWkXT5L35 6YEOgE//lENRH2gw8vYR0DRz0/A+o0gjd3av+UjNI17JgKE90YmdfG7KwIDbWgN1dKesiv /3tDr2KwyvCNzEdZYV6mRpqUMnYGrgt+WoyEO5GPKU12AqNiqsjVCKTJCyf64CdchBFsQW +n289/MspNJ3KPyH7D6iXu3001VnD2aTUJyQLg1VvpBHX+cBS6m9+21rfpUe+8OS2nhX3y bGqsP1OXTEw7ZyXL2ETGElFx6Wl/8dXHprCrzacMyU9heMT9D83wpJzJRoQzaQ== ARC-Seal: i=1; a=rsa-sha256; d=freebsd.org; s=dkim; cv=none; t=1790697349; b=iA3rZu3N5GADlAuMgYqqQmTGsiSs37r78bLk6q/PI9zyFoeMoraZ3nlSUn1CM+t4mw/YON uuYeQVVyCcGZFZBvA8Om/3R6ehCA9R9wfyJSA5IDjkATKHWueUO5iX0LL+iVq6qshjQ1cB gjKdVsI9KNPXggoUPXSSTm/MfBkUGgSevxyJTjqULR/Lx/AkUBW9x64zbfbC+GjEFMY4dM Q08e/byi45aE114q4l4zCLmtsAQY1vCThZayTPVtgV0bICnz24+ewUM2rNH0Lmf8AXhVN6 vZvqrbAtiupT53qVypSOr4RCUlL4islm/8Y3zcRBnqQ827cBaVMqxXYAmMzOfg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1790697349; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=qNbmGDxR4H/6TaFo439lEgL32XObVC4te6WCkle8MIU=; b=Fpj/HlOGhUhwqrhXhV55pENe2KpunqIer6MFboxqi1qnxcI61tJtOrjLhKdpaOHmBaGOGe o+oUgEtDK/wZb+E28V8Mq+Q+lujxfaHNDqjYjffLMVhIdRrqPXXLurrJ65ErmOCesJ3LFq +/pGL5Cp3+N4Y663pwBdgX1e5F3hFCDD7wNSNBts1JAy0Dwj+jULuLGDGHyWHPt16/JWez DW+bSD6fs3WV2XWx7868Sk6mNmdRLuNUEs6ZTlCDKS6n4t1f+VsOR1AQN4OkXTCAXWViRy dM/0zm+0F8JP4i2NxZ6NKYwlKAJTcdgmL0YPO3AA46XHKS8rKwG18JMwSiW5hA== ARC-Authentication-Results: i=1; mx1.freebsd.org; none Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4hvN7T1hDdz1KNB for ; Tue, 29 Sep 2026 15:55:49 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 27adc by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Tue, 29 Sep 2026 15:55:49 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mark Johnston Subject: git: 9c10f4c021dd - main - vfs: Disallow renameat() with FD_RESOLVE_BENEATH descriptors List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@FreeBSD.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: markj X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 9c10f4c021ddd272ec4352412cf75880424bc70c Auto-Submitted: auto-generated Date: Tue, 29 Sep 2026 15:55:49 +0000 Message-Id: <6abbdf85.27adc.7ff93bb1@gitrepo.freebsd.org> The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=9c10f4c021ddd272ec4352412cf75880424bc70c commit 9c10f4c021ddd272ec4352412cf75880424bc70c Author: Mark Johnston AuthorDate: 2026-09-28 16:47:56 +0000 Commit: Mark Johnston CommitDate: 2026-09-29 15:54:16 +0000 vfs: Disallow renameat() with FD_RESOLVE_BENEATH descriptors The FD_RESOLVE_BENEATH flag was intended to try to resolve bugzilla PR 262179 without entirely disallowing fd passing between jails. However, one can use renameat() to bypass the restriction: upon receiving a directory fd with FD_RESOLVE_BENEATH set, a jailed process can still move its CWD or one of its ancestors to the directory, and just cd out of its jail root. So disallow renameat() when either the source or destination directory fds has FD_RESOLVE_BENEATH set, like we do with fchdir() and fchroot() to prevent similar escapes. Approved by: so Security: FreeBSD-SA-26:66.jail Security: CVE-2026-101305 PR: 262179 Reported by: firk@cantconnect.ru Reviewed by: olce, kib Differential Revision: https://reviews.freebsd.org/D59875 --- lib/libsys/fcntl.2 | 9 ++++++++- sys/kern/vfs_syscalls.c | 9 +++++++++ 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/lib/libsys/fcntl.2 b/lib/libsys/fcntl.2 index b919e1b8674b..123dd5543ab2 100644 --- a/lib/libsys/fcntl.2 +++ b/lib/libsys/fcntl.2 @@ -25,7 +25,7 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.Dd June 24, 2025 +.Dd September 22, 2026 .Dt FCNTL 2 .Os .Sh NAME @@ -173,6 +173,13 @@ and similar operations, and opening a directory with .Xr openat 2 where the directory descriptor has the flag set causes the new directory descriptor to also have the flag set. +A file descriptor with the +.Dv FD_RESOLVE_BENEATH +set cannot be used as either the source or target descriptor in +.Xr renameat 2 +or +.Xr renameat2 2 +system calls. .El .It Dv F_SETFD Set flags associated with diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c index 9bae2cd6b854..0a7fcaca6a77 100644 --- a/sys/kern/vfs_syscalls.c +++ b/sys/kern/vfs_syscalls.c @@ -3869,6 +3869,15 @@ again: error = EEXIST; goto out; } + if (fvp->v_type == VDIR && + ((fromnd.ni_resflags | tond.ni_resflags) & NIRES_BENEATH) != 0) { + /* + * We must not rename a directory relative to FD_RESOLVE_BENEATH + * descriptors. + */ + error = ENOTCAPABLE; + goto out; + } if (exchange) { if (tvp == NULL) { error = ENOENT;