From nobody Fri Jul 24 22:36:26 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 4h6NBg0BWfz6mr7t for ; Fri, 24 Jul 2026 22:36:27 +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 4h6NBf6bjJz3r44 for ; Fri, 24 Jul 2026 22:36:26 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1784932586; 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=Ths+qi3JJpi7VwcooQDHweSiaJkSFyDlOb/o0KYe/ps=; b=lI9ZFnIXJjb8mj3t/dPLm9R1XpCi0fvOjOPqOB+KP/S4RfglBbNl0JU83b5H2b7PYWzs1u g+isEV+14L9k7PPok2J1frxm8wYWnaZZ5tEvXSDC3pIIvJ6db2mq4dZwaqaam65Q6dD5d5 +HPzt1+p1XQ7Qv3K4HhOy94uZMh9sySOt2aImlJwJD9P2YzyTYYGvDNuTs74gv5RPoJJpF NgKXUljoK+z0W0N8drl1Zz4UuaI9WPKWTs9xsRiKUdeUhqTb7xWqnQR3YUhoMZS2VRXJkX 4r3C0khEwhZHqTsRuFurJc0tbcB+lGvLVn9trH1iAjCLZ7+x0sAG9H71ax6OIA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1784932586; a=rsa-sha256; cv=none; b=OCURWT4sEsrbjfg+bnkUwB3lfHEjtz/9pX4AGo2pRJqj7bXuqtpJUS4aqshrkkPm4IAEAu 10VgHqgmP0Nm5rxs1oAExycn+DL4K6QPzJcuCSM/9uqZVrapK4lFrpLYWpIMYPiJGfyxx9 vem1WjCxMin6fbOhMi5ldIgOBnOyWj69/aLoz/G2xliDZgAeBTiwZ05FrPPGES012Ld/qq d7OrmRyT6n5mZ5wo9rOLDtRpOGvMa6BPZSwhhLidqH6i7PVHwUvHCuNDlwxXIdwIhqKR92 Evp8XtKV0hw0SgcM0XYi4x+gOB1WjH2SPqgzSNppCnnpKXe2xRVD9zTRvmN50Q== 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=1784932586; 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=Ths+qi3JJpi7VwcooQDHweSiaJkSFyDlOb/o0KYe/ps=; b=QcWeyirSnGVQoNVGA80POct4FzcI5/Hkv9RkMa5BKJn8MW44Wfv+xEOyf8CLyibU/V5y+d 1eWweurHJLhbyq4T+LYbX+KxXe6rtvXYO9oR3AKTull59E5Y/uzzp1+M5mzYFVHY7D82dc uWEXf/ommSJ8SPNbTQpKwGz1mQ3WGx9Cnf9Z1gBYntuCpYbL2Ou5PcJgyc79Lw8TGKYw5r ISThKc6QOOfAj6km4ezgA62AxwYjU5zpUqqK0d5ZBTdfFQ1yvtRkto12LphJVqFiy6L/kf Rx82oGSsJckF8lXE22M5dZ2PrKJeZ69TJSp1bOhXB+bsCOc4QhuA3+yMXYvjiA== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4h6NBf5Qltz19PB for ; Fri, 24 Jul 2026 22:36:26 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 3fc3d by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Fri, 24 Jul 2026 22:36:26 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mark Johnston Subject: git: 492cfbe9e2f8 - main - uma: Enqueue full buckets in FIFO order when KASAN is configured 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: 492cfbe9e2f831fff290e019dae66345146978bd Auto-Submitted: auto-generated Date: Fri, 24 Jul 2026 22:36:26 +0000 Message-Id: <6a63e8ea.3fc3d.5cce49ee@gitrepo.freebsd.org> The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=492cfbe9e2f831fff290e019dae66345146978bd commit 492cfbe9e2f831fff290e019dae66345146978bd Author: Mark Johnston AuthorDate: 2026-07-24 21:12:33 +0000 Commit: Mark Johnston CommitDate: 2026-07-24 21:18:49 +0000 uma: Enqueue full buckets in FIFO order when KASAN is configured We want to defer reuse of free objects, and this is a trivial way to promote that. Suggested by: rlibby Reviewed by: rlibby, alc MFC after: 1 month Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D58312 --- sys/vm/uma_core.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/sys/vm/uma_core.c b/sys/vm/uma_core.c index e5f7d92a4f2a..d4a98d0b8463 100644 --- a/sys/vm/uma_core.c +++ b/sys/vm/uma_core.c @@ -869,6 +869,8 @@ zone_put_bucket(uma_zone_t zone, int domain, uma_bucket_t bucket, void *udata, */ zdom->uzd_nitems += bucket->ub_cnt; if (__predict_true(zdom->uzd_nitems < zone->uz_bucket_max)) { + bool head; + if (ws) { zone_domain_imax_set(zdom, zdom->uzd_nitems); } else { @@ -887,8 +889,14 @@ zone_put_bucket(uma_zone_t zone, int domain, uma_bucket_t bucket, void *udata, /* * Try to promote reuse of recently used items. For items * protected by SMR, try to defer reuse to minimize polling. + * If KASAN is configured, try to defer reuse to improve UAF + * detection. */ - if (bucket->ub_seq == SMR_SEQ_INVALID) + head = bucket->ub_seq == SMR_SEQ_INVALID; +#ifdef KASAN + head = head && (zone->uz_flags & UMA_ZONE_NOKASAN) != 0; +#endif + if (head) STAILQ_INSERT_HEAD(&zdom->uzd_buckets, bucket, ub_link); else STAILQ_INSERT_TAIL(&zdom->uzd_buckets, bucket, ub_link);