From nobody Fri Aug 18 04:03:57 2023 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 4RRpCK559kz4qc3Z; Fri, 18 Aug 2023 04:03:57 +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 "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4RRpCK4Pbzz3ddR; Fri, 18 Aug 2023 04:03:57 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1692331437; 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=pAejLlSelIxx13AFby1jK4GVIbgfmmAXRnyHTrZVojY=; b=Zk/nDbe+Sp4m6TeQPBePpkCbuGDDyw2uELOjcjMMlR3BiN7l75FwTWMBIBXRynbI7ae1Bj OUpi1Vo/T2mts4gcRPq51K3uKEfx7Y9L3hrEWZub98D0U9hk/SYtTl2Obr4VU8tO7aM6Ks CD+DCbvX4dqYdsfejX1yw2byx9uJSnDF3waT0eQXBrU/yk7LIEIV5xhVHhxJx/8Rz4AZeL x1Fkbs0g5zQL6iiq9OypfULBkVxm7VUzkBCtLBwOCOYA4og2FK3lhJAsg67u8HT02LXCoG bvs97mE/AlE6tRVvshebN4+JEwIFE255RGOBgbFcixFpaXVk7z2gJR6wkhsS1g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1692331437; 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=pAejLlSelIxx13AFby1jK4GVIbgfmmAXRnyHTrZVojY=; b=dqHx5I6Cjw5I1UfVv93RN8WotEwYdh1oe6sWStn9vgB+UZ3HL3THesS0IFZ3TW1E53oMgC Op7+pOZXDYy8EiEqsfwgSjhKIu/HwlZ+OOkR8qVFbSWrxnIzCEWlVe9agjvNNiCWOGiMpD /l2hs0X0MWumjkcYPRr7Xe8GoMJS8j1PVinToHPq8vvfKVSacpak5BctbDqjkmP/gtnvEq FfqK8GNur5B9wQGZowf4pBCu/fELEio5y4GSXLivT1ph+R0cxTKRW/QeUAAnDdhQ1GvzCU v+1gRah1VK+FHbS6S09+ckOPj06exdIhAlPBkkIsdc5U9YQ8AYNOCmjp7KHZ8g== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1692331437; a=rsa-sha256; cv=none; b=t98YozohKEJ7RSadbJwoHQhuT90QR11EOp8oAef8rsrfVTyF563C/J1QjSlxy9n1h5yuNj BJ7wWGCpfHWC5rucbUvH9Wl2sjI6sfCnV/zoOXYrtBQtl8f9AEe0aTXae4kuyKdTtRTn4t amoZ/q01VnZUmcf1HzJTZsRP67S736xXTyjIBCEymvOwmev4VEymPt9YFaV0j608bmxzRi 1bVesVRTbBmr6QPTHQLG3HfOwH1u0wRCJGSPe6xs/FAkdBK95mT2OYoJoUN5Tip8rLlJtY jJGfd8yUcWKN/bT9b5c1LwbIy8tnSv6da53xJRW4xR1njygg1fR9bCr0OLpAyg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none 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 4RRpCK3Gbcz11kP; Fri, 18 Aug 2023 04:03:57 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.17.1/8.17.1) with ESMTP id 37I43vfG098758; Fri, 18 Aug 2023 04:03:57 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.17.1/8.17.1/Submit) id 37I43vjm098755; Fri, 18 Aug 2023 04:03:57 GMT (envelope-from git) Date: Fri, 18 Aug 2023 04:03:57 GMT Message-Id: <202308180403.37I43vjm098755@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Kyle Evans Subject: git: f0ebed6a313b - stable/13 - kern: osd: avoid dereferencing freed slots 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: Sender: owner-dev-commits-src-branches@freebsd.org X-BeenThere: dev-commits-src-branches@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kevans X-Git-Repository: src X-Git-Refname: refs/heads/stable/13 X-Git-Reftype: branch X-Git-Commit: f0ebed6a313b8cdd91859287aad8015392352bc1 Auto-Submitted: auto-generated The branch stable/13 has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=f0ebed6a313b8cdd91859287aad8015392352bc1 commit f0ebed6a313b8cdd91859287aad8015392352bc1 Author: Kyle Evans AuthorDate: 2023-08-10 17:32:33 +0000 Commit: Kyle Evans CommitDate: 2023-08-18 04:02:46 +0000 kern: osd: avoid dereferencing freed slots If a slot is freed that isn't the last one, we'll set its destructor to NULL to indicate that it's been freed and leave a hole in the slot map. Check osd_destructors in osd_call() to avoid dereferencing a method that is potentially from a module that's been unloaded. This scenario would most commonly surface when two modules are loaded that osd_register(), then the earlier one deregisters and an osd_call() is made after the fact. In the specific report that triggered the investigation, kldload if_wg -> kldload linux* -> kldunload if_wg -> destroy a jail -> panic. Noted in the review, but left for follow-up work, is that the realloc that may happen in osd_deregister() should likely go away and the assumption that reallocating to a smaller size cannot fail is actually not correct. Reported by: dim (cherry picked from commit 2bd446d7f1a03fbf6d98ace4548f8793599f48fb) --- sys/kern/kern_osd.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/sys/kern/kern_osd.c b/sys/kern/kern_osd.c index 23178731b899..ced6df31cf44 100644 --- a/sys/kern/kern_osd.c +++ b/sys/kern/kern_osd.c @@ -396,6 +396,9 @@ osd_call(u_int type, u_int method, void *obj, void *data) error = 0; sx_slock(&osdm[type].osd_module_lock); for (i = 0; i < osdm[type].osd_ntslots; i++) { + /* Hole in the slot map; avoid dereferencing. */ + if (osdm[type].osd_destructors[i] == NULL) + continue; methodfun = osdm[type].osd_methods[i * osdm[type].osd_nmethods + method]; if (methodfun != NULL && (error = methodfun(obj, data)) != 0)