From nobody Wed Sep 04 15:53:51 2024 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 4WzRqg2YLHz5V8Qm; Wed, 04 Sep 2024 15:53:51 +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 4WzRqg232jz4VNb; Wed, 4 Sep 2024 15:53:51 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1725465231; 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=higPZzbVejQtBdOSr3YdKVShRxVkHCTNZ0xe/Iqaa2U=; b=jTH380ZTyGWE5lJ2ihGl/tkGZ44oWX0fLt1GDr6jlYcIEM2KlTajlUZwC+b0p80Wj1v9ut ZehsvHcIGCjyBeQGNzhptxndamxyvHth92bkkPwryHw4TsoyKwVdteSG/WVSsgpyHDmf5+ fw6v1MK/ZHSS31Gpt+8lNqSwo46dyaxRWhSR/xLOxb6NU5kNVQU7eh8OefUAZAp1s8h12B Qhf4hqqQjzwEt8r1juHptyoo98SsCe9PyD+QqG3EkLT03WflIdzrRiTxP31smbVAVD6VUq kOBhpU6zkRhrV+W1bvpMNvunT756bxC/3DULOnxeNEUZ/pZeAQw2yj+LfNSpxg== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1725465231; a=rsa-sha256; cv=none; b=Q6wdT0mcgUtO6F7L3EMBtofqzM4ZZnD2zddYNroXiF0HRR1sSkM25NaByC3AhXpeh7mC39 GKs8GHcZxfyTKFBQBP50d4110xFlqmyDI4p0HnrMr6z9aidHnJxzSQNe5u8a8M2cX+LmJn 3B8LpXxzNYhNSgihTWCxNuNR5PLhZmz+r5FZxLbzc34CKa6cBkv+XVfStgxY1Z0xoZO5qQ VY4Y0ot+AvibYlQu+E/AnVxx0WV3hEfxTMCJsnPlruCXkZrrk6jOym/89W2MYYs6l3zfLW 1QiObXk6iKm4iHX3HMrKLtTw3eUWNj88/rXDP+y14lbYc1gcMdhG19HxlgXaIQ== 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=1725465231; 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=higPZzbVejQtBdOSr3YdKVShRxVkHCTNZ0xe/Iqaa2U=; b=tHwRsm8Ffzcr60onOc9nIgmyy7NlgdvJsfd85F6muaxYKXRgqKTwcVzIDtwFMihW36PjDy 8gisa43hYvNmyyWrbPfd+EtNnvYorSg9P2TyDu/bBwzyR1DRY+TTO0f8c2m1DFC2Ezcxys 8kcKzZAyPgNCyTajU7uSKE6MIuQN4Z4YxXeZPiZ2vmreuFGogSDYdjy6t8gF+ZMxkzYgNp p+SLu9Mk6drY1yBcFFVi2j+XMTBMESZHs5EMR9CWD5HAEkpvaP5yYCCCz66wlmsmZ25r5r 41WoD5tCkkZWX5CM5IBV2CPtq/yb/FCWDcGxEyBENlTlT2jB/rxbIZky9NMFVA== 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 4WzRqg1fcBzWlG; Wed, 4 Sep 2024 15:53:51 +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 484FrphC019751; Wed, 4 Sep 2024 15:53:51 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 484FrpwC019748; Wed, 4 Sep 2024 15:53:51 GMT (envelope-from git) Date: Wed, 4 Sep 2024 15:53:51 GMT Message-Id: <202409041553.484FrpwC019748@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: 2553c91f731b - stable/13 - ctl: fix Use-After-Free in ctl_write_buffer 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 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/stable/13 X-Git-Reftype: branch X-Git-Commit: 2553c91f731b12558046454cf30eb83f56fb204b Auto-Submitted: auto-generated The branch stable/13 has been updated by emaste: URL: https://cgit.FreeBSD.org/src/commit/?id=2553c91f731b12558046454cf30eb83f56fb204b commit 2553c91f731b12558046454cf30eb83f56fb204b Author: Alan Somers AuthorDate: 2024-09-04 14:38:11 +0000 Commit: Ed Maste CommitDate: 2024-09-04 15:52:06 +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) --- 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 7a04a668e823..5635246845b9 100644 --- a/sys/cam/ctl/ctl.c +++ b/sys/cam/ctl/ctl.c @@ -5672,21 +5672,24 @@ 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 9a87345015fa..85f4f6137810 100644 --- a/sys/cam/ctl/ctl_private.h +++ b/sys/cam/ctl/ctl_private.h @@ -410,6 +410,14 @@ 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;