From nobody Tue Jun 30 17:22:03 2026 X-Original-To: dev-commits-src-all@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 4gqVM04Z8Nz6jZ5d for ; Tue, 30 Jun 2026 17:22:04 +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 4gqVM00YSVz3t6G for ; Tue, 30 Jun 2026 17:22:04 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1782840124; 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=QBfViiJVgwSCf7IYX9Vrm3r+gutBD5RTEfHTxDZDgGw=; b=L1Fue7cMsoX5pxn8pro33Pnc/eBV2EmR/Nb5BBDCjxq+gN/jubsjMcGwVE6eRLp9jUOSYY itob6AGNaOykF/EEBwQmGmphzM0AxQN5/z+qksbiNHYGelnIcJbRBHZQb9vVcaPOAoEWkz gydWcC6Rd2VOpXU998S68zIzBw6+I5fqWXpWuj+fcS4O6q2xOR4LRmMfHpjgi7muKQJlg8 skbZfwDbmJr+qC6Go/8D7QDKhhW/9Syf98MfL+rekSNiBZsWppGJ6tbirFdz+00wL9Vgb6 O5w99aUZROAELVsYWVgWgPsEaXVfT2TTV55hhmXymqngPnhavK2ofx45Bx0TTQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1782840124; a=rsa-sha256; cv=none; b=B0dOd46UW1Uhp+Gyu5PzFyMrhCg3xLyHS0Lmo+Rffnwh/CkxMaZftzXvGsbN+dpZMNf6wt IsT4Bf+NfT5lTBjkLv+CuelqlamJaLcGKn5uaqHFt4WYH/lySUDL5Hx0d6gBA69CcLusey Vk/ek3T+Uv4uVfBgxotuNjN1hmLMblqqbZVaOoOHHPC6vIYYXeHzGaoqINL02sVKR5anUX Yt+aVal5Hkcd1CHW1iv3WQEfKeV/4YAR5UZ6iXF2v/ZWdUsnzQcibTH4C1v6KsZZLeLolw S5CogkjFtwpheixEvKlZhhZJ86cDBTyDxJEmhqRFJFpEQaswJ6wmQlNDR0fL8w== 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=1782840124; 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=QBfViiJVgwSCf7IYX9Vrm3r+gutBD5RTEfHTxDZDgGw=; b=VDMM0fKXZaDs1Tj8sAXqHrTzuWlu/n24Mfqzt7TxixH1BGnb8pR6beLJuU/jMn9zZ6dvEG GnZF8jxbgZcTmF+6IcYXZNtn1/0TW8JrJrnWmRM78qrTbXB+XVSIZUaSWyWuKrWCP/Tg7N Mr3Ynu1XZdMWmKHzT7vjaVE9m5EWq/y7jxLHatz9gRD3ymv9ZXAx1JeHfs/heTnkCWRYDx HTdKKDIRu9xX3kq663rvjPjFSMhG5UFbsJQOWsycywWzeDgAEMTT4gfnX/nTB5rpfXShYX ItslloZRVGTalXVyUqOr1qCl8CTwoQ/0UwGnqvMjysbkSeEpV5fSk1j4CtwGMg== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4gqVLz6DxkztYX for ; Tue, 30 Jun 2026 17:22:03 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 45d4d by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Tue, 30 Jun 2026 17:22:03 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Mark Johnston Subject: git: b15971f462b6 - releng/15.1 - posixshm: Fix handling of sendfile() with largepage objects List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@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/releng/15.1 X-Git-Reftype: branch X-Git-Commit: b15971f462b6af68aeb8468bddc55efa6ca0bc95 Auto-Submitted: auto-generated Date: Tue, 30 Jun 2026 17:22:03 +0000 Message-Id: <6a43fb3b.45d4d.1ed2f36f@gitrepo.freebsd.org> The branch releng/15.1 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=b15971f462b6af68aeb8468bddc55efa6ca0bc95 commit b15971f462b6af68aeb8468bddc55efa6ca0bc95 Author: Mark Johnston AuthorDate: 2026-06-24 19:57:00 +0000 Commit: Mark Johnston CommitDate: 2026-06-29 19:16:41 +0000 posixshm: Fix handling of sendfile() with largepage objects sendfile(2) can transmit POSIX shared memory objects. Typically it will look up and wire each page before sending it to a socket; once transmission is complete, the page is unwired and typically released back into the page queues. sendfile() has an advisory flag, SF_NOCACHE, which means, "try to free the page once transmission is complete." This is implemented in vm_page_release(), which expects to operate on managed pages. Pages belonging a largepage object are de-facto wired not explicitly so. Thus, vm_page_release() will unwire and, having found no additional references, free the page. Because mappings of largepage objects are unmanaged, userspace can still access the now freed page. Fix the problem by explicitly wiring largepage pages. Make the VM object destructor responsible for unwiring and freeing them. Add a regression test. Approved by: so Security: FreeBSD-SA-26:44.posixshm Security: CVE-2026-49427 Reported by: Chris Jarrett-Davies Reviewed by: kib Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D57832 --- sys/kern/uipc_shm.c | 22 ++++++++-- sys/vm/vm_page.c | 23 +++++----- tests/sys/posixshm/posixshm_test.c | 89 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 121 insertions(+), 13 deletions(-) diff --git a/sys/kern/uipc_shm.c b/sys/kern/uipc_shm.c index b1b6a8657d69..8341364f4d16 100644 --- a/sys/kern/uipc_shm.c +++ b/sys/kern/uipc_shm.c @@ -326,6 +326,7 @@ static void shm_largepage_phys_ctor(vm_object_t object, vm_prot_t prot, vm_ooffset_t foff, struct ucred *cred) { + object->flags |= OBJ_PG_DTOR; } static void @@ -333,11 +334,27 @@ shm_largepage_phys_dtor(vm_object_t object) { int psind; + VM_OBJECT_ASSERT_WLOCKED(object); + psind = object->un_pager.phys.data_val; if (psind != 0) { + struct pctrie_iter pages; + vm_page_t m; + bool removed __diagused; + + vm_page_iter_init(&pages, object); +restart: + VM_RADIX_FOREACH(m, &pages) { + if (!vm_page_busy_acquire(m, VM_ALLOC_WAITFAIL)) { + pctrie_iter_reset(&pages); + goto restart; + } + removed = vm_page_iter_remove(&pages, m); + KASSERT(!removed, ("%s: page %p not wired", __func__, m)); + vm_page_unwire(m, PQ_NONE); + } atomic_subtract_long(&count_largepages[psind], object->size / (pagesizes[psind] / PAGE_SIZE)); - vm_wire_sub(object->size); } else { KASSERT(object->size == 0, ("largepage phys obj %p not initialized bit size %#jx > 0", @@ -818,7 +835,7 @@ shm_dotruncate_largepage(struct shmfd *shmfd, off_t length, void *rl_cookie) if ((shmfd->shm_seals & F_SEAL_GROW) != 0) return (EPERM); - aflags = VM_ALLOC_NORMAL | VM_ALLOC_ZERO; + aflags = VM_ALLOC_NORMAL | VM_ALLOC_ZERO | VM_ALLOC_WIRED; if (shmfd->shm_lp_alloc_policy == SHM_LARGEPAGE_ALLOC_NOWAIT) aflags |= VM_ALLOC_WAITFAIL; try = 0; @@ -874,7 +891,6 @@ shm_dotruncate_largepage(struct shmfd *shmfd, off_t length, void *rl_cookie) object->size += OFF_TO_IDX(pagesizes[psind]); shmfd->shm_size += pagesizes[psind]; atomic_add_long(&count_largepages[psind], 1); - vm_wire_add(atop(pagesizes[psind])); } return (0); } diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c index 3753079f2fde..cd95cc620ad4 100644 --- a/sys/vm/vm_page.c +++ b/sys/vm/vm_page.c @@ -4272,6 +4272,9 @@ vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse) { u_int old; + KASSERT(nqueue < PQ_COUNT, + ("vm_page_unwire: invalid queue %u request for page %p", + nqueue, m)); KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("%s: page %p is unmanaged", __func__, m)); @@ -4330,17 +4333,15 @@ vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse) void vm_page_unwire(vm_page_t m, uint8_t nqueue) { - - KASSERT(nqueue < PQ_COUNT, - ("vm_page_unwire: invalid queue %u request for page %p", - nqueue, m)); + KASSERT(nqueue < PQ_COUNT || nqueue == PQ_NONE, + ("%s: invalid queue %u request for page %p", __func__, nqueue, m)); if ((m->oflags & VPO_UNMANAGED) != 0) { if (vm_page_unwire_noq(m) && m->ref_count == 0) vm_page_free(m); - return; + } else { + vm_page_unwire_managed(m, nqueue, false); } - vm_page_unwire_managed(m, nqueue, false); } /* @@ -4514,13 +4515,15 @@ vm_page_release_toq(vm_page_t m, uint8_t nqueue, const bool noreuse) void vm_page_release(vm_page_t m, int flags) { - vm_object_t object; - - KASSERT((m->oflags & VPO_UNMANAGED) == 0, - ("vm_page_release: page %p is unmanaged", m)); + if ((m->oflags & VPO_UNMANAGED) != 0) { + vm_page_unwire(m, PQ_NONE); + return; + } if ((flags & VPR_TRYFREE) != 0) { for (;;) { + vm_object_t object; + object = atomic_load_ptr(&m->object); if (object == NULL) break; diff --git a/tests/sys/posixshm/posixshm_test.c b/tests/sys/posixshm/posixshm_test.c index e816e2d1efa7..e4b57dec6311 100644 --- a/tests/sys/posixshm/posixshm_test.c +++ b/tests/sys/posixshm/posixshm_test.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include #include @@ -2148,6 +2149,93 @@ ATF_TC_BODY(largepage_reopen, tc) "close failed; errno=%d", errno); } +static unsigned char +largepage_sendfile_expected(size_t off) +{ + + return ((unsigned char)(off * 131 + (off >> 8))); +} + +ATF_TC_WITHOUT_HEAD(largepage_sendfile); +ATF_TC_BODY(largepage_sendfile, tc) +{ + static const int flags[] = { 0, SF_NOCACHE }; + char *addr; + off_t sbytes; + size_t ps[MAXPAGESIZES]; + int error, fd, pscnt, sd[2], status; + pid_t child; + + pscnt = pagesizes(ps, true); + + for (int i = 1; i < pscnt; i++) { + for (int fi = 0; fi < (int)nitems(flags); fi++) { + fd = shm_open_large(i, SHM_LARGEPAGE_ALLOC_DEFAULT, + ps[i]); + addr = mmap(NULL, ps[i], PROT_READ | PROT_WRITE, + MAP_SHARED, fd, 0); + ATF_REQUIRE_MSG(addr != MAP_FAILED, + "mmap(%zu bytes) failed; error=%d", ps[i], errno); + + /* Fill with a verifiable pattern. */ + for (size_t j = 0; j < ps[i]; j++) + addr[j] = largepage_sendfile_expected(j); + + ATF_REQUIRE(socketpair(PF_LOCAL, SOCK_STREAM, 0, + sd) == 0); + + child = fork(); + ATF_REQUIRE_MSG(child != -1, + "fork() failed; error=%d", errno); + if (child == 0) { + char buf[BUFSIZ]; + ssize_t len; + size_t off, resid; + + (void)close(sd[0]); + off = 0; + for (resid = ps[i]; resid > 0; resid -= len) { + len = read(sd[1], buf, sizeof(buf)); + if (len <= 0) + _exit(1); + for (ssize_t k = 0; k < len; k++) { + if ((unsigned char)buf[k] != + largepage_sendfile_expected( + off + k)) + _exit(2); + } + off += len; + } + _exit(0); + } + ATF_REQUIRE(close(sd[1]) == 0); + + sbytes = 0; + error = sendfile(fd, sd[0], 0, ps[i], NULL, &sbytes, + flags[fi]); + ATF_REQUIRE_MSG(error == 0, + "sendfile() failed; error=%d flags=%#x", + errno, flags[fi]); + ATF_REQUIRE_MSG(sbytes == (off_t)ps[i], + "sendfile() short; sbytes=%jd expected=%zu flags=%#x", + (intmax_t)sbytes, ps[i], flags[fi]); + + ATF_REQUIRE(close(sd[0]) == 0); + + ATF_REQUIRE_MSG(waitpid(child, &status, 0) == child, + "waitpid() failed; error=%d", errno); + ATF_REQUIRE_MSG(WIFEXITED(status), + "child killed by signal %d", WTERMSIG(status)); + ATF_REQUIRE_MSG(WEXITSTATUS(status) == 0, + "child exited with status %d (flags=%#x)", + WEXITSTATUS(status), flags[fi]); + + ATF_REQUIRE(munmap(addr, ps[i]) == 0); + ATF_REQUIRE(close(fd) == 0); + } + } +} + ATF_TC_WITHOUT_HEAD(largepage_truncate); ATF_TC_BODY(largepage_truncate, tc) { @@ -2236,6 +2324,7 @@ ATF_TP_ADD_TCS(tp) ATF_TP_ADD_TC(tp, largepage_pkru); #endif ATF_TP_ADD_TC(tp, largepage_reopen); + ATF_TP_ADD_TC(tp, largepage_sendfile); ATF_TP_ADD_TC(tp, largepage_truncate); return (atf_no_error());