From nobody Thu Aug 6 15:01:31 2026 X-Original-To: dev-commits-src-branches@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 4hG9Tm44yDz6nB2X for ; Thu, 06 Aug 2026 15:01:32 +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 "YR1" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4hG9Tl4Cv8z3Dn6 for ; Thu, 06 Aug 2026 15:01:31 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1786028491; 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=6cNs2/hWYupYPkhg0odDJjHmcPF+yMDxBiYWnXimvgk=; b=EP2C5lVYmYuKg4GB2cTOnWAFV4lSuA9psF7oPYCUjtYQ+GhHWSobLkdtE73JM1wzl+guPe Gbx5Cs1xejkLh99gf/+KKjiMKMJSb6NL6tArZs+AZ28OG32AQ7+Q76mA2ijqPS9GwBrHGE r0ga7z6i7SVMFUSZOgtToOssQrvwsy3DHDgk3t9a6zIgGs+Wio+wwAyM38xU0GT07mXuF0 O7j+IWmzOgU4bhqT9Mj8zYFL3u91pV+omTE4Xe+ltpiug4pFNUV8P0AsbVmpXc2gYaN7S2 r64a/3/cwTMYD9s+zq+pWbGmcjcQPzdxgtMP/K0tOLtaLvd8dfYTQrvSC4rEMA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1786028491; a=rsa-sha256; cv=none; b=RPhvzU37GKeTJxI2/7+dBu9pHsKU9skCkPejKj1gGsnwKxK90gSvUveSFPspr7ed0U/wrD JYcl3ogP/ifiIvFgvWgKDdphgqnn/0Ddf5YnIzhV7sXvzthLpykWz7j7yBNxtyUTMXhl6U 0y46IOrvAGkfZqJkQegntyG24xJa8er4w8v9YXp2GKU0WIOPSIDcM8iUcTARRSt4YeBKeK jk122lrDVaGbPrLLvuiRH1WbkgcZX72KCkFthU/zAOhIH9qTd6LS2Lk/J/oQcCnS+yhJh5 Y2dbSK35VbStyJd/bd5yDcaFV2mVEA1zWthoWmpYs9yXxYgsts+w6ZFpESgD7g== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1786028491; 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=6cNs2/hWYupYPkhg0odDJjHmcPF+yMDxBiYWnXimvgk=; b=yQSReuY+2uQOCHCfzhRIgAU0KRBzLNW4S//SEvOeVXL0RsGAWRku8mzJFOCau58xyQn2SB jBH6ioZdLI0s59DP/zR/kX6lvV5R2LkNH4yptTNa/mCy1/AMCU36MalCP/VciZrB9Hqh1M wlK8+5fgcZmytfeeEYxlaS2XIny6WOS2oFUcSPpZCxbQNscFnHmaLIy5hqoBCJ3AqRxTKI +ylyLBtNIqufF+KuQiuRqyKSHj7V4OcvakQxX0F8XgoCm/yw+FycHb9eMJJA27F8SUcAqL O6Sa7WoLfge5KN9B72YMCUvg8ndnW+ZmI5AbnUxMmMt8kiPKqeRi5aeSHr2dHA== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4hG9Tl2Yvwz9XC for ; Thu, 06 Aug 2026 15:01:31 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 45e56 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Thu, 06 Aug 2026 15:01:31 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Mark Johnston Subject: git: 30758138f2e3 - stable/15 - unix: Preserve FD_RESOLVE_BENEATH when passing an fd List-Id: Commits to the stable branches of the FreeBSD src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-branches List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-branches@freebsd.org Sender: owner-dev-commits-src-branches@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/stable/15 X-Git-Reftype: branch X-Git-Commit: 30758138f2e36d89bc30cb686796ccc4dfa8b475 Auto-Submitted: auto-generated Date: Thu, 06 Aug 2026 15:01:31 +0000 Message-Id: <6a74a1cb.45e56.769fc93e@gitrepo.freebsd.org> The branch stable/15 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=30758138f2e36d89bc30cb686796ccc4dfa8b475 commit 30758138f2e36d89bc30cb686796ccc4dfa8b475 Author: Mark Johnston AuthorDate: 2026-07-24 20:06:05 +0000 Commit: Mark Johnston CommitDate: 2026-08-06 12:52:28 +0000 unix: Preserve FD_RESOLVE_BENEATH when passing an fd The FD_RESOLVE_BENEATH flag is supposed to be sticky. It's set when you receive an fd from a different jail and preserved by openat() etc.. However, if you send the fd to yourself, the flag is stripped since SCM_RIGHTS message don't preserve file descriptor flags. Fix this by preserving those flags and checking for UF_RESOLVE_BENEATH in restrict_rights(). Fixes: 350ba9672a7f ("unix: Set O_RESOLVE_BENEATH on fds transferred between jails") Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D58317 (cherry picked from commit 586e2b3d89d6e70ab7e4a88497b5f36d78719423) --- sys/kern/uipc_usrreq.c | 27 +++++++++++++++++++-------- tests/sys/kern/unix_passfd_test.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 50 insertions(+), 8 deletions(-) diff --git a/sys/kern/uipc_usrreq.c b/sys/kern/uipc_usrreq.c index bbea5ef3914c..ed3e22ad63f6 100644 --- a/sys/kern/uipc_usrreq.c +++ b/sys/kern/uipc_usrreq.c @@ -3488,15 +3488,25 @@ unp_freerights(struct filedescent **fdep, int fdcount) free(fdep[0], M_FILECAPS); } -static bool -restrict_rights(struct file *fp, struct thread *td) +/* + * Flags to set on the receiving side when externalizing a file descriptor. + * When transferring fds between jails, ensure that the receiver cannot use + * a dirfd to escape the jail chroot. + */ +static int +externalize_fdflags(struct filedescent *fde, struct thread *td) { struct prison *prison1, *prison2; - prison1 = fp->f_cred->cr_prison; + if ((fde->fde_flags & UF_RESOLVE_BENEATH) != 0) + return (O_RESOLVE_BENEATH); + prison1 = fde->fde_file->f_cred->cr_prison; prison2 = td->td_ucred->cr_prison; - return (prison1 != prison2 && prison1->pr_root != prison2->pr_root && - prison2 != &prison0); + if (prison1 != prison2 && prison1->pr_root != prison2->pr_root && + prison2 != &prison0) + return (O_RESOLVE_BENEATH); + else + return (0); } static int @@ -3562,9 +3572,9 @@ unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags) struct file *fp; fp = fdep[i]->fde_file; - _finstall(fdesc, fp, *fdp, fdflags | - (restrict_rights(fp, td) ? - O_RESOLVE_BENEATH : 0), &fdep[i]->fde_caps); + _finstall(fdesc, fp, *fdp, + fdflags | externalize_fdflags(fdep[i], td), + &fdep[i]->fde_caps); unp_externalize_fp(fp); } @@ -3800,6 +3810,7 @@ unp_internalize(struct mbuf *control, struct mchain *mc, struct thread *td) fdep[i]->fde_file = fde->fde_file; filecaps_copy(&fde->fde_caps, &fdep[i]->fde_caps, true); + fdep[i]->fde_flags = fde->fde_flags; unp_internalize_fp(fdep[i]->fde_file); } FILEDESC_SUNLOCK(fdesc); diff --git a/tests/sys/kern/unix_passfd_test.c b/tests/sys/kern/unix_passfd_test.c index 66bb406ea14e..566591522784 100644 --- a/tests/sys/kern/unix_passfd_test.c +++ b/tests/sys/kern/unix_passfd_test.c @@ -1189,6 +1189,36 @@ ATF_TC_CLEANUP(cross_jail_dirfd, tc) err(1, "jail_remove"); } +/* + * Verify that FD_RESOLVE_BENEATH is preserved when an fd is passed over a UNIX + * domain socket. + */ +ATF_TC_WITHOUT_HEAD(resolve_beneath_preserved); +ATF_TC_BODY(resolve_beneath_preserved, tc) +{ + int fd[2], getfd, putfd, fdflags; + + domainsocketpair(fd); + tempfile(&putfd); + + fdflags = fcntl(putfd, F_GETFD); + ATF_REQUIRE(fdflags != -1); + ATF_REQUIRE(fcntl(putfd, F_SETFD, fdflags | FD_RESOLVE_BENEATH) != -1); + ATF_REQUIRE((fcntl(putfd, F_GETFD) & FD_RESOLVE_BENEATH) != 0); + + sendfd(fd[0], putfd); + recvfd(fd[1], &getfd, 0); + + fdflags = fcntl(getfd, F_GETFD); + ATF_REQUIRE(fdflags != -1); + ATF_REQUIRE_MSG((fdflags & FD_RESOLVE_BENEATH) != 0, + "FD_RESOLVE_BENEATH was not preserved across SCM_RIGHTS transfer"); + + ATF_REQUIRE(close(putfd) == 0); + ATF_REQUIRE(close(getfd) == 0); + closesocketpair(fd); +} + ATF_TC_WITHOUT_HEAD(listening_socket); ATF_TC_BODY(listening_socket, tc) { @@ -1239,6 +1269,7 @@ ATF_TP_ADD_TCS(tp) ATF_TP_ADD_TC(tp, empty_rights_message); ATF_TP_ADD_TC(tp, control_creates_records); ATF_TP_ADD_TC(tp, cross_jail_dirfd); + ATF_TP_ADD_TC(tp, resolve_beneath_preserved); ATF_TP_ADD_TC(tp, listening_socket); return (atf_no_error());