From nobody Tue Sep 29 15:55:47 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 4hvN7R2s7yz6tl5r for ; Tue, 29 Sep 2026 15:55:47 +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 4hvN7R153Fz4Sxx for ; Tue, 29 Sep 2026 15:55:47 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1790697347; 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=IjBVMfv/enCEmQwzDgtn/bUbPt6dti5OtEz+007R3Hs=; b=pF1ZijQzG/gAAGSrnGLFrH7aMHfOM/wzoh+KssQlD4BoCecUZj/TwingVrXisSnXsX3Oeh UD2t1jzfeGWF1hZPiY9qOAQqHNLFJlFEHWcT3q/UpDl3ffe7kVicxW5zMVNzIQp7dtm0dM pLlcSNw++mGwzDr5LanCy6yU2nU1NOadfscUkQLVwXzAVfchlRwYam8hRdsZRiecMzaGv+ vt1gERAvrwJYSoXuXvHXRpMYWp30FmJ16h31A9+3URrRVC0ZD+TedqINFPhy20/ZCV7sBD V42dyOiiRM54wBhAziBlPLNb9rS8BltwGjhD95f4DqFL0gGUqyKEEA+ARObTlQ== ARC-Seal: i=1; a=rsa-sha256; d=freebsd.org; s=dkim; cv=none; t=1790697347; b=SBxVl1Wx2gcgTiAxNwKFtGhg4QRIJl63sPkeM4sdxjTyRCE2wCFNwv2hTCtYpgKlCyH2SR YcNZUWIyIHpGNv/tnSehhI3CYYhfauJMvu8y3TYDvn+EInYG+JaA8opmFXoKRHQ6Blz8TB sDrsXaoN/P29pLU+z/S39VoJZFFbu3VcjN76KJvsTNqmK+nzxgL4xTmEP/Zx7qXP5Q3xa9 8s/x6iskeNrquslUpu5p3UKFODP1Pbu/XfZGdDXczVL2AMWCXA5TgeaAa2PUYXy2R/DGBF X4GBCBIpS0DHbL+XBPTjNnoGUYUYSb6HwUgChbmMiAcJnofD0po4d26DX4TINw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1790697347; 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=IjBVMfv/enCEmQwzDgtn/bUbPt6dti5OtEz+007R3Hs=; b=M+udHgFgeqTXI+rj+kiqtcqhRxOB/rkanVElHLHdRNvgkcXO6t1laSyUp9+3cyg565hnNc wW6rDe823cewJLKQom0oMmu+N8eLRBlXSGArmM6h0xM1x7lkysOxbr9f5H5kTAl34su2qg dmUxnfFPh2E2ylSPjO+hF5tfY/zr2fadbPvt27zhGYIB3TDnkwZjI+Kn9mHGnJLf8vxPAp DYmOEd9afR9qGeGbC+dAT62rzpIDwv27ut4zmO48j0u/d41o00O0mIaB4CpbTLGUV/gteb KEMLQeRQEuh9sYqZTYKA0Wsp+uywugqcRYL1CW19bk/XXhTJPGaWPy3outCEJw== 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 4hvN7R08NQz1K1w for ; Tue, 29 Sep 2026 15:55:47 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 26841 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Tue, 29 Sep 2026 15:55:47 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mark Johnston Subject: git: dfc979fb8e21 - main - file: Add filecaps_intersect() and cap_rights_intersect() 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: dfc979fb8e210b565c4e291b6e67205733b6e663 Auto-Submitted: auto-generated Date: Tue, 29 Sep 2026 15:55:47 +0000 Message-Id: <6abbdf83.26841.2a9b23fd@gitrepo.freebsd.org> The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=dfc979fb8e210b565c4e291b6e67205733b6e663 commit dfc979fb8e210b565c4e291b6e67205733b6e663 Author: Mark Johnston AuthorDate: 2026-09-28 14:43:23 +0000 Commit: Mark Johnston CommitDate: 2026-09-29 15:54:16 +0000 file: Add filecaps_intersect() and cap_rights_intersect() These routines let one compute the intersection of two sets of filecaps or capability rights, just as filecaps_merge() and cap_rights_merge() compute the union. This will be useful in an upcoming patch. filecaps_intersect() is complex due to the need to merge sets of ioctls. For now this is implemented with a dumb nested loop on the basis that ioctl lists are typically short enough that this is fine. It may be better to instead sort the two lists first and step through them together. No functional change intended. Approved by: so Security: FreeBSD-SA-26:66.jail Reviewed by: kib Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D59885 --- lib/libc/capability/cap_rights_init.3 | 16 ++++++++++-- sys/kern/kern_descrip.c | 49 +++++++++++++++++++++++++++++++++++ sys/kern/subr_capability.c | 23 ++++++++++++++++ sys/sys/capsicum.h | 1 + sys/sys/filedesc.h | 1 + 5 files changed, 88 insertions(+), 2 deletions(-) diff --git a/lib/libc/capability/cap_rights_init.3 b/lib/libc/capability/cap_rights_init.3 index 98b50f653f2c..1dbb76686283 100644 --- a/lib/libc/capability/cap_rights_init.3 +++ b/lib/libc/capability/cap_rights_init.3 @@ -35,6 +35,7 @@ .Nm cap_rights_is_set , .Nm cap_rights_is_empty , .Nm cap_rights_is_valid , +.Nm cap_rights_intersect , .Nm cap_rights_merge , .Nm cap_rights_remove , .Nm cap_rights_contains @@ -56,6 +57,8 @@ .Ft bool .Fn cap_rights_is_valid "const cap_rights_t *rights" .Ft cap_rights_t * +.Fn cap_rights_intersect "cap_rights_t *dst" "const cap_rights_t *src" +.Ft cap_rights_t * .Fn cap_rights_merge "cap_rights_t *dst" "const cap_rights_t *src" .Ft cap_rights_t * .Fn cap_rights_remove "cap_rights_t *dst" "const cap_rights_t *src" @@ -133,6 +136,14 @@ function verifies if the given structure is valid. .Pp The +.Fn cap_rights_intersect +function clears all capability rights from the +.Fa dst +structure that are not present in the +.Fa src +structure, leaving only the rights common to both. +.Pp +The .Fn cap_rights_merge function merges all capability rights present in the .Fa src @@ -173,9 +184,10 @@ structure given in the argument. .Pp The -.Fn cap_rights_merge -and +.Fn cap_rights_merge , .Fn cap_rights_remove +and +.Fn cap_rights_intersect functions return pointer to the .Vt cap_rights_t structure given in the diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c index b169a3a677c3..80735e0b4c0c 100644 --- a/sys/kern/kern_descrip.c +++ b/sys/kern/kern_descrip.c @@ -1945,6 +1945,55 @@ filecaps_full(const struct filecaps *fcaps) fcaps->fc_fcntls == CAP_FCNTL_ALL && fcaps->fc_nioctls == -1); } +/* + * Find the intersection of two filecaps structures and store the result in the + * first structure. This is a destructive operation on the src structure. + */ +void +filecaps_intersect(struct filecaps *src, struct filecaps *dst) +{ + + cap_rights_intersect(&dst->fc_rights, &src->fc_rights); + dst->fc_fcntls &= src->fc_fcntls; + if (dst->fc_nioctls == -1) { + dst->fc_ioctls = src->fc_ioctls; + dst->fc_nioctls = src->fc_nioctls; + src->fc_ioctls = NULL; + } else if (src->fc_nioctls != -1) { + int count; + + /* + * ioctl lists are usually short, so this dumb merge is fine. + * We could alternately sort both lists and walk them in + * parallel. + */ + count = 0; + for (int i = 0; i < dst->fc_nioctls; i++) { + bool found; + + found = false; + for (int j = 0; j < src->fc_nioctls; j++) { + if (dst->fc_ioctls[i] == src->fc_ioctls[j]) { + count++; + found = true; + break; + } + } + if (!found) { + if (i != dst->fc_nioctls - 1) + dst->fc_ioctls[i] = + dst->fc_ioctls[dst->fc_nioctls - 1]; + dst->fc_nioctls--; + i--; + } + } + dst->fc_nioctls = count; + } + if (dst->fc_nioctls == 0) + filecaps_free_ioctl(dst); + filecaps_free(src); +} + static u_long * filecaps_free_prep(struct filecaps *fcaps) { diff --git a/sys/kern/subr_capability.c b/sys/kern/subr_capability.c index f5242216a2a2..72636980b1b1 100644 --- a/sys/kern/subr_capability.c +++ b/sys/kern/subr_capability.c @@ -316,6 +316,29 @@ cap_rights_is_valid(const cap_rights_t *rights) return (true); } +cap_rights_t * +cap_rights_intersect(cap_rights_t *dst, const cap_rights_t *src) +{ + unsigned int i, n; + + assert(CAPVER(dst) == CAP_RIGHTS_VERSION_00); + assert(CAPVER(src) == CAP_RIGHTS_VERSION_00); + assert(CAPVER(dst) == CAPVER(src)); + assert(cap_rights_is_valid(src)); + assert(cap_rights_is_valid(dst)); + + n = CAPARSIZE(dst); + assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX); + + for (i = 0; i < n; i++) + dst->cr_rights[i] &= src->cr_rights[i] | ~0x01FFFFFFFFFFFFFFULL; + + assert(cap_rights_is_valid(src)); + assert(cap_rights_is_valid(dst)); + + return (dst); +} + cap_rights_t * cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src) { diff --git a/sys/sys/capsicum.h b/sys/sys/capsicum.h index d912d10bc4e2..03173b02375d 100644 --- a/sys/sys/capsicum.h +++ b/sys/sys/capsicum.h @@ -391,6 +391,7 @@ bool __cap_rights_is_set(const cap_rights_t *rights, ...); bool cap_rights_is_empty(const cap_rights_t *rights); bool cap_rights_is_valid(const cap_rights_t *rights); +cap_rights_t *cap_rights_intersect(cap_rights_t *dst, const cap_rights_t *src); cap_rights_t *cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src); cap_rights_t *cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src); diff --git a/sys/sys/filedesc.h b/sys/sys/filedesc.h index 0f878e530436..a2bb6c671dbb 100644 --- a/sys/sys/filedesc.h +++ b/sys/sys/filedesc.h @@ -246,6 +246,7 @@ void filecaps_move(struct filecaps *src, struct filecaps *dst); void filecaps_fill(struct filecaps *fcaps); void filecaps_free(struct filecaps *fcaps); bool filecaps_full(const struct filecaps *fcaps); +void filecaps_intersect(struct filecaps *src, struct filecaps *dst); int closef(struct file *fp, struct thread *td); void closef_nothread(struct file *fp);