From nobody Wed Feb 25 17:10:12 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 4fLh152L4zz6THnB for ; Wed, 25 Feb 2026 17:10:17 +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 "R12" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4fLh151smlz3XZf for ; Wed, 25 Feb 2026 17:10:17 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1772039417; 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=oCUgFhAKH/l6eV0LNJ+oRmuBekLZv8aUmqw68qg91l8=; b=dzw7F/wP9NXVaoaUUcWTGcDY/Qqu55+DyyO/UAKyYoDzAjA6ANSnWLbCvF0hkz9pS0k5DC Io3lGiSQAhVbh8zDx2O3naIqs/FTkVyLHX/lQBbwbmwpEM9CeLazll2/GbAGiEdFuObW0L j7bv1DLj5cazdUNnimHVrLfVi5e8VDdm/I1jXE8cHqxG8UgZzj903POXxJqv0ttfqn2J8z DdbPTFvAdN5BwwC5siNPFHkDz+VG347caWKK2z/jE3MmzqZrkJzn5e2Cegzjz4HVtyiyFN TZKXbSqOl6epDtVnjgf/7H8Fy7eSl4zmPDHbbHVjlj/+y+3bOcCPqatzHBxxBg== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1772039417; a=rsa-sha256; cv=none; b=iravScpz3e2KU7tm4d5L2APwH1CCI0xbBE9JZp9sPKTiv+0W0J1gea93An8tL8mEUb5C9X UfdKnbRsmQaNGp7x9ScjkaL0NlsgCGeOs1K/XOocpPPydcumgoL4G2T3RbL0E2B2Ly72Ag wHICOW0nqodgEKsyfyi1GU4GBeOULzX4HG0XrN1TY6ND+ynmJNYR0eQM5Te7zZfO3vnmiP re5H2xPqQkhOm6bVo0LQNBXJxRM2A6Xc3kmxIhMHGULAa5HrkzhUhjP5QzyadlILgmym3e YqisUKeKuKK0G5rj4pXi7nUbwgNPzYB8APYF8j/JPNNAjJlhT7oFvJeDEclPBg== 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=1772039417; 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=oCUgFhAKH/l6eV0LNJ+oRmuBekLZv8aUmqw68qg91l8=; b=pQOfy1Z6oc6dDjIH4pJ1ZYFeUjqS9pfmC8gj0sfn5lEfdoAs7PBCP+lqSXNJOcZSDK1p0r 4w1AcareswKtxodVaPFjCUtzEo/OwmVQ15tQtPmeSHVi+cF/g+nh/U8IefMJjiY1kjL0jL TCx6H6TQg9zKjhmw/bFRZHN8RfPKG7Kva/5YYmtoVZ9TdK7JlwYKALm3OXium9eICrZTjS ZLwr7WzjBovSZa4yck9FYE0rf/oqsAuybY2p3WeEIzBDLhzHQlF+TsYK+y53m9T73HEFtG gt92dDyFi75HjlSg40aOJ0hQfg0KbjvztftAZ8FmmiJKZQY8My7iDWUHDuF3ig== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4fLh151RGYz18tb for ; Wed, 25 Feb 2026 17:10:17 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 34474 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Wed, 25 Feb 2026 17:10:12 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mark Johnston Subject: git: 8b64d46fab87 - main - nullfs: Fix handling of doomed vnodes in nullfs_unlink_lowervp() 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: markj X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 8b64d46fab87af3ae062901312187f3a04ad2d67 Auto-Submitted: auto-generated Date: Wed, 25 Feb 2026 17:10:12 +0000 Message-Id: <699f2cf4.34474.243e2fe@gitrepo.freebsd.org> The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=8b64d46fab87af3ae062901312187f3a04ad2d67 commit 8b64d46fab87af3ae062901312187f3a04ad2d67 Author: Mark Johnston AuthorDate: 2026-02-25 15:31:30 +0000 Commit: Mark Johnston CommitDate: 2026-02-25 15:31:30 +0000 nullfs: Fix handling of doomed vnodes in nullfs_unlink_lowervp() nullfs_unlink_lowervp() is called with the lower vnode locked, so the nullfs vnode is locked too. The following can occur: 1. the vunref() call decrements the usecount 2->1, 2. a different thread calls vrele() on the vnode, decrements the usecount 0->1, then blocks on the vnode lock, 3. the first thread tests vp->v_usecount == 0 and observes that it is true, 4. the first thread incorrectly unlocks the lower vnode. Fix this by testing VN_IS_DOOMED directly. Since nullfs_unlink_lowervp() holds the vnode lock, the value of the VIRF_DOOMED flag is stable. Thanks to leres@ for patiently helping to track this down. PR: 288345 MFC after: 1 week Reviewed by: kib Differential Revision: https://reviews.freebsd.org/D55446 --- sys/fs/nullfs/null_vfsops.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/sys/fs/nullfs/null_vfsops.c b/sys/fs/nullfs/null_vfsops.c index 170a3dd51cd8..c3eec727aeea 100644 --- a/sys/fs/nullfs/null_vfsops.c +++ b/sys/fs/nullfs/null_vfsops.c @@ -461,16 +461,12 @@ nullfs_unlink_lowervp(struct mount *mp, struct vnode *lowervp) vhold(vp); vunref(vp); - if (vp->v_usecount == 0) { + if (VN_IS_DOOMED(vp)) { /* - * If vunref() dropped the last use reference on the - * nullfs vnode, it must be reclaimed, and its lock - * was split from the lower vnode lock. Need to do - * extra unlock before allowing the final vdrop() to - * free the vnode. + * If the vnode is doomed, its lock was split from the lower + * vnode lock. Therefore we need to do an extra unlock before + * allowing the final vdrop() to free the vnode. */ - KASSERT(VN_IS_DOOMED(vp), - ("not reclaimed nullfs vnode %p", vp)); VOP_UNLOCK(vp); } else { /* @@ -480,8 +476,6 @@ nullfs_unlink_lowervp(struct mount *mp, struct vnode *lowervp) * relevant for future reclamations. */ ASSERT_VOP_ELOCKED(vp, "unlink_lowervp"); - KASSERT(!VN_IS_DOOMED(vp), - ("reclaimed nullfs vnode %p", vp)); xp->null_flags &= ~NULLV_NOUNLOCK; } vdrop(vp);