From nobody Wed Sep 04 21:07:30 2024 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 4WzZnZ3BkYz5VP0M; Wed, 04 Sep 2024 21:07:30 +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 "R11" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4WzZnZ272Mz4Vc3; Wed, 4 Sep 2024 21:07:30 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1725484050; 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=k6a2S5HMQiQ0Ed6/nZcZI2s5UsjSt3CGvxxIPauUDDc=; b=WhqY1+mYGiaVm537RXpgyn2GXK1iaCyOoUAdXSoygrISf8HJsbnAoD/DUupylygUlwull/ uMjXHd6aWC20SiQattHGde56bZc2etkWjCiqkFB/tnlTOhB3S6ALXXqPTvlgVQzEA0Xg/H w2DX/UPBkqWtRMAk903IrllfuF0C2oqFl2y6sW4S5UbkFaaHU7R5l8H58/J/zBGRfTEDZk WPNZUZWwo2e4Rsv5djTEwEvPjCsjpvSlw/518sO0vo0BDHOacL+d0SCCjD7rYmlF4K/tlM KA8w9jIif+qBfkdnvHgnkyAlIkDjzVegtIzz6dRiR+nDDtoZfbbD02HYQsNYHA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1725484050; a=rsa-sha256; cv=none; b=A2F6L6SDQKIKbdfmlMV5n1doMkxASrsTXEMdW1MOtU1g+/eRTP49luEyamMKjghnnYWcx3 CYKiP3+hctfYiqKmonnaODNGFYBbhhyyltyHmVZwRzJxDZP+crcn2wiHktaziGTf1/Ukol DcRXsXU+VbX4MB0AdOUNHJxe1IxslU+6lmORDhrhkV0NCJ8+WLUtKC6yyPi3ADwFIwmqLt 4+KSIZWwcCB01QjTWFY0oDWoVCDbrlLM/F1pXEDl4xWH0gssFfaBNZaijzQJfHaKruJTwJ rYkLGVGncJFJoRaGvW9YCWrs5oIFlCGNWIcx3nAR5smdUHG2VioFBYZRHoAZ+g== 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=1725484050; 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=k6a2S5HMQiQ0Ed6/nZcZI2s5UsjSt3CGvxxIPauUDDc=; b=sE50lcE0Tdo1EoOcDFjNoN650w+CHzL2JvjjkQIVWdx+P399/OaVH3y+2/etLJkfoozhzy AELGGVcsgDL8XAoypo0nIfezZJD2uplt6wJ6X/cC6c5u4qP7paSktb1+Whc+j9lnESAOvE DQVlVa6SGIihZ3NPmX1jbdbUAB3+W+6i3Xxi/bIa/o07r1zOTG1+BFEEyvSwKcd1ePGT0i jj+4Gzd1Ezvh7XQv42i8kubBUgIczA1/sfuD9rsNAZRC177SdZUElhYQIfHgYP9tuGZHyq mViXBMfQ91mJZ2BkjagpPR/y6CcrBt67GkLKGpA4UZVp+gBh1CT6pIN8uAzJ2Q== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (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 did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4WzZnZ17lBzgcS; Wed, 4 Sep 2024 21:07:30 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 484L7Umt053188; Wed, 4 Sep 2024 21:07:30 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 484L7U57053185; Wed, 4 Sep 2024 21:07:30 GMT (envelope-from git) Date: Wed, 4 Sep 2024 21:07:30 GMT Message-Id: <202409042107.484L7U57053185@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Ed Maste Subject: git: 31d839d66e8a - releng/14.1 - ctl: fix Use-After-Free in ctl_write_buffer 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 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: emaste X-Git-Repository: src X-Git-Refname: refs/heads/releng/14.1 X-Git-Reftype: branch X-Git-Commit: 31d839d66e8a10693e791696ea4bfd93ec1feb34 Auto-Submitted: auto-generated The branch releng/14.1 has been updated by emaste: URL: https://cgit.FreeBSD.org/src/commit/?id=31d839d66e8a10693e791696ea4bfd93ec1feb34 commit 31d839d66e8a10693e791696ea4bfd93ec1feb34 Author: Alan Somers AuthorDate: 2024-09-04 14:38:11 +0000 Commit: Ed Maste CommitDate: 2024-09-04 20:46:54 +0000 ctl: fix Use-After-Free in ctl_write_buffer The virtio_scsi device allows a guest VM to directly send SCSI commands to the kernel driver exposed on /dev/cam/ctl. This setup makes the vulnerability directly accessible from VMs through the pci_virtio_scsi bhyve device. The function ctl_write_buffer sets the CTL_FLAG_ALLOCATED flag, causing the kern_data_ptr to be freed when the command finishes processing. However, the buffer is still stored in lun->write_buffer, leading to a Use-After-Free vulnerability. Since the buffer needs to persist indefinitely, so it can be accessed by READ BUFFER, do not set CTL_FLAG_ALLOCATED. Reported by: Synacktiv Reviewed by: Pierre Pronchery Reviewed by: jhb Security: FreeBSD-SA-24:11.ctl Security: CVE-2024-45063 Security: HYP-03 Sponsored by: Axcient Sponsored by: The Alpha-Omega Project Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D46424 (cherry picked from commit 670b582db6cb827a8760df942ed8af0020a0b4d0) (cherry picked from commit 29937d7a1a0a3061c6ae12b5b35cc32b03829501) Approved by: so --- sys/cam/ctl/ctl.c | 19 +++++++++++-------- sys/cam/ctl/ctl_private.h | 8 ++++++++ 2 files changed, 19 insertions(+), 8 deletions(-) diff --git a/sys/cam/ctl/ctl.c b/sys/cam/ctl/ctl.c index a315c5ef7df3..7fb38c794a4c 100644 --- a/sys/cam/ctl/ctl.c +++ b/sys/cam/ctl/ctl.c @@ -5673,21 +5673,24 @@ ctl_write_buffer(struct ctl_scsiio *ctsio) return (CTL_RETVAL_COMPLETE); } + if (lun->write_buffer == NULL) { + lun->write_buffer = malloc(CTL_WRITE_BUFFER_SIZE, + M_CTL, M_WAITOK); + } + /* - * If we've got a kernel request that hasn't been malloced yet, - * malloc it and tell the caller the data buffer is here. + * If this kernel request hasn't started yet, initialize the data + * buffer to the correct region of the LUN's write buffer. Note that + * this doesn't set CTL_FLAG_ALLOCATED since this points into a + * persistent buffer belonging to the LUN rather than a buffer + * dedicated to this request. */ - if ((ctsio->io_hdr.flags & CTL_FLAG_ALLOCATED) == 0) { - if (lun->write_buffer == NULL) { - lun->write_buffer = malloc(CTL_WRITE_BUFFER_SIZE, - M_CTL, M_WAITOK); - } + if (ctsio->kern_data_ptr == NULL) { ctsio->kern_data_ptr = lun->write_buffer + buffer_offset; ctsio->kern_data_len = len; ctsio->kern_total_len = len; ctsio->kern_rel_offset = 0; ctsio->kern_sg_entries = 0; - ctsio->io_hdr.flags |= CTL_FLAG_ALLOCATED; ctsio->be_move_done = ctl_config_move_done; ctl_datamove((union ctl_io *)ctsio); diff --git a/sys/cam/ctl/ctl_private.h b/sys/cam/ctl/ctl_private.h index 04846f80e913..db8e748ec014 100644 --- a/sys/cam/ctl/ctl_private.h +++ b/sys/cam/ctl/ctl_private.h @@ -411,6 +411,14 @@ struct ctl_lun { uint8_t pr_res_type; int prevent_count; uint32_t *prevent; + + /* + * The READ_BUFFER and WRITE_BUFFER commands permit access to a logical + * data buffer associated with a LUN. Accesses to the data buffer do + * not affect data stored on the storage medium. To support this, + * allocate a buffer on first use that persists until the LUN is + * destroyed. + */ uint8_t *write_buffer; struct ctl_devid *lun_devid; TAILQ_HEAD(tpc_lists, tpc_list) tpc_lists;