From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dy1-f199.google.com (mail-dy1-f199.google.com [74.125.82.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6B3A35650F4 for ; Tue, 13 Oct 2026 22:40:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791931237; cv=none; b=XHzVUEACN0J85cU6eKdn9w2tqpWLWmru5+YGcm+VjYsXng4p+Dv4kMwveWDtT06+3fzHnPFnYYQ4ngMcpmDS3QZpUv8jgAzm5TbMOdA7HVnLp4Iz+RaCNcaYPwfPKkcrv4zdxpPafIn2QNwCKdFoxOxqP6adjbSDrCEmlr/Ic4Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791931237; c=relaxed/simple; bh=GRIZQKuwWcuCjR8A0ylF/V4G5/ojiWDtGgUJc8zlstU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Bz2gVCOpQljyQx6hinHIr4hNSwZIgQxqP25Tzq8YUD7dtVGixd9pOJ/MCZhRasX5Qp2OwaszyRJ151vcLzWFdxbRsN4TwvxyUDkvxIv4WTMXlNHDZml4Eaxzb91JmNi4200dTzVBna2zvYHSY0SkkdtCGiRYQZGbpDVOKMv0IzI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=LLZQC176; arc=none smtp.client-ip=74.125.82.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="LLZQC176" Received: by mail-dy1-f199.google.com with SMTP id 5a478bee46e88-33713e5e6daso5245473eec.0 for ; Tue, 13 Oct 2026 15:40:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1791931229; x=1792536029; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=zqg4bcg4yTM1CSL1NV7gzxaOXxYgsDcagY96onRKZWw=; b=LLZQC176s1Ef4mQ4adKARyI+43Apa3IxBXu3faIYCpG3v5a7cb+aXuooqfsbCbJX+7 FWrx9GIDZKUvDKWwTPQe4trZi2UuTun1mZfq/UMv3d30Y3x1s291xy+7ChZGIBh5Hj2W OoxuPfzruTuIBTQOGze/ucRooh3UPIug+xd0A74hTwR0zRBf39QASLFJQ1OA/bgn01yv TS9pq5kiLNp+aPVN6sDZTHL+mw0lDMrhTF2ImzmICSlXxxAhyI2ex0zNcV68cYqQQsOC QVvnCVsGGupaXn01437NlFicAb+gwNW3AsLb3YyCwvsgFJFll+OSob0L+3KGmvWhJ7mX zt0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791931229; x=1792536029; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=zqg4bcg4yTM1CSL1NV7gzxaOXxYgsDcagY96onRKZWw=; b=qS/6ro2zGdcnZnPDKe6opsl8UFGFJ0TXxeg2DdcT7bR8uTrKaSzxrFCLIASd9BUWI4 C8NHuqnSp7eK1OsuoUI1wFp6CBc2iThJwGInyo+iO3MgGJBOnBBNOc9iF8IGK8JOtMij WQMwx2eTFqP7Ec8C/DkV5yDSFxI15E0+XVwh2lKbV/vOkBCcLTST08NWqJDcoBRas3Ui yV3UpkXnwNIrgbGSRr62Y6O0bJcSPWUZ4TOYHDLyeD2pBl67gfW5r7e3WARn+ebwQPFT XsjccEWLy7soKhubKlorrO5jVcZ+xPFWzv2blU5ePX5EGMbKLOoVemSDqzjoVM1TbRoP hH7A== X-Forwarded-Encrypted: i=1; AKwUvBxyaezWoT+xinI6lefxHQW7J1oYXBdjaEXhdrJISyVF2WH9vFVlByRR3fP0lyhun0rC+Kk2ILgBbKh9klg=@vger.kernel.org X-Gm-Message-State: AFq9FYL0TlIlZV2nOp3P1KdLgWi0zNs/OGgbb+sNaH/ui13wma3qopfB +ett7fLSUim26n7z3fYIJk7dAWmsgv70aI9gXym+2Evf68dFKLyWPioMfZ/slmtU2KSD4C+E9G4 MUC20I/idwQ== X-Received: from dldyq19-n1.prod.google.com ([2002:a05:701b:4553:10b0:164:47f8:a96a]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:701b:4286:10b0:144:c128:4c4b with SMTP id a92af1059eb24-16a5e49c474mr18578865c88.36.1791931226644; Tue, 13 Oct 2026 15:40:26 -0700 (PDT) Date: Tue, 13 Oct 2026 15:39:41 -0700 In-Reply-To: <20261013223946.1836757-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20261013223946.1836757-1-irogers@google.com> X-Mailer: git-send-email 2.56.0.385.gd3acb90ef8-goog Message-ID: <20261013223946.1836757-7-irogers@google.com> Subject: [PATCH 06/11] dlm: Free dlm_ls in kobject release callback From: Ian Rogers To: Greg Kroah-Hartman , "Rafael J . Wysocki" , Danilo Krummrich , Miguel Ojeda , Kees Cook , Nathan Chancellor Cc: Nick Desaulniers , Bill Wendling , Justin Stitt , Jonathan Corbet , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Nayna Jain , Yoshinori Sato , Rich Felker , John Paul Adrian Glaubitz , Viresh Kumar , David Teigland , Alexander Aring , Juergen Gross , Stefano Stabellini , Oleksandr Tyshchenko , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Richard Weinberger , Zhihao Cheng , Felix Kuehling , Alex Deucher , "=?UTF-8?q?Christian=20K=C3=B6nig?=" , driver-core@lists.linux.dev, llvm@lists.linux.dev, linux-hardening@vger.kernel.org, linux-doc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org, linux-pm@vger.kernel.org, linux-acpi@vger.kernel.org, gfs2@lists.linux.dev, xen-devel@lists.xenproject.org, linux-s390@vger.kernel.org, linux-mtd@lists.infradead.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Ian Rogers Content-Type: text/plain; charset="UTF-8" struct dlm_ls embeds a struct kobject (ls_kobj), but dlm_ktype lacked a .release callback and dlm freed the lockspace structure directly via kfree(ls). With CONFIG_DEBUG_KOBJECT_RELEASE=y, freeing ls before the kobject release runs causes a use-after-free. Add dlm_ls_release() to free struct dlm_ls when the last reference to ls_kobj is dropped, use kobject_del() in release_lockspace(), and drop the final kobject reference in free_lockspace(). Fixes: 3514faca19a6 ("kobject: remove struct kobj_type from struct kset") Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Ian Rogers --- fs/dlm/lockspace.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c index a9c98b4f378f..1d226b27d8e6 100644 --- a/fs/dlm/lockspace.c +++ b/fs/dlm/lockspace.c @@ -179,7 +179,15 @@ static const struct sysfs_ops dlm_attr_ops = { .store = dlm_attr_store, }; +static void dlm_ls_release(struct kobject *kobj) +{ + struct dlm_ls *ls = container_of(kobj, struct dlm_ls, ls_kobj); + + kfree(ls); +} + static struct kobj_type dlm_ktype = { + .release = dlm_ls_release, .default_groups = dlm_groups, .sysfs_ops = &dlm_attr_ops, }; @@ -355,7 +363,7 @@ static void free_lockspace(struct work_struct *work) */ rhashtable_free_and_destroy(&ls->ls_rsbtbl, rhash_free_rsb, NULL); - kfree(ls); + kobject_put(&ls->ls_kobj); } static int new_lockspace(const char *name, const char *cluster, @@ -436,6 +444,8 @@ static int new_lockspace(const char *name, const char *cluster, atomic_set(&ls->ls_count, 0); init_waitqueue_head(&ls->ls_count_wait); ls->ls_flags = 0; + ls->ls_kobj.kset = dlm_kset; + kobject_init(&ls->ls_kobj, &dlm_ktype); if (ops && dlm_config.ci_recover_callbacks) { ls->ls_ops = ops; @@ -567,9 +577,7 @@ static int new_lockspace(const char *name, const char *cluster, wait_event(ls->ls_recover_lock_wait, test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags)); - ls->ls_kobj.kset = dlm_kset; - error = kobject_init_and_add(&ls->ls_kobj, &dlm_ktype, NULL, - "%s", ls->ls_name); + error = kobject_add(&ls->ls_kobj, NULL, "%s", ls->ls_name); if (error) goto out_recoverd; kobject_uevent(&ls->ls_kobj, KOBJ_ADD); @@ -615,7 +623,6 @@ static int new_lockspace(const char *name, const char *cluster, rhashtable_destroy(&ls->ls_rsbtbl); out_lsfree: kobject_put(&ls->ls_kobj); - kfree(ls); out: module_put(THIS_MODULE); return error; @@ -759,7 +766,7 @@ static int release_lockspace(struct dlm_ls *ls, unsigned int release_option) dlm_delete_debug_file(ls); - kobject_put(&ls->ls_kobj); + kobject_del(&ls->ls_kobj); xa_destroy(&ls->ls_recover_xa); kfree(ls->ls_recover_buf); -- 2.56.0.385.gd3acb90ef8-goog