From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8875A47CC99 for ; Wed, 17 Jun 2026 15:15:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781709353; cv=none; b=Dsx+OzBl1ohF8sfrNNRqRcRFiw9k59k52ZH6gL32y7MsLaIwfx4OrXAE1dyWqonuEsNWaob4biEKBfs6qZg48wA2Uyyrwr9cw2Kd6UOWknUX9MErlIinVwtnJe2FW+M3kzdiGWqV/GhQ/bZ75KuM/QVevd3+DSF1p1O/YiJsfoo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781709353; c=relaxed/simple; bh=0LcnSJThiJ0aOQnWjxru4SxED/oeyb3aQv9Yp6tSZeg=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=Widdg2nAy7OgyewtRfCGzvN5zm9gzQfrxeX+RGI6+L2rL9QA0kKvYwbsdS/AShL+OkTPEt1C/wyo5DV3Mp1Nv9Ahj5z/v5Yhp5iCC1RsbAMz2tgGE4aCe80c4fqdLLsKFL5+WDZTWDT0pjX01e9GOGC5ramWI59Stzvgr6QkmWc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=En09T8lC; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="En09T8lC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E28B01F000E9; Wed, 17 Jun 2026 15:15:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781709351; bh=COlNkjiF1c9Mcpxa0r9jZOeZ0ah2e2EwSsqBj9o/vso=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=En09T8lCQcLzB37YDEjeJnfqnUG/WA9H7LHii371HqcmPXcvstfH4eWXsua9E6b82 VlSo0Gk10lOVbM37iCkzURG0KrwsggMwXoeQXYSEpvWGAgaaAqnxZjGOisB4dqab2P x34paCJunwHFKml+53UFPxn4RhY/D+TL5QMavVGQksyRE0t3eCwK3QWIX02NcFIWDf L0wusekhaAbXMvpFuGJwVB8MAb9JjbkaRF/kNjCjl//FTWwf+HMpw1dym+iDeIDME0 hNFjitqSkp4n3GtZ4uINd313mi0o2gY1+BgL5xbYPeLFYyrQGBf4tewYkTfMFpBhSC d+lRjgfKFKUhA== From: sashiko-bot@kernel.org Subject: Re: [RFC PATCH v1.1 07/11] mm/damon/sysfs-schemes: kobject_del() scheme action destination dirs Reply-To: sashiko-reviews@lists.linux.dev To: "SeongJae Park" Cc: damon@lists.linux.dev In-Reply-To: <20260617144807.91441-8-sj@kernel.org> References: <20260617144807.91441-1-sj@kernel.org> <20260617144807.91441-8-sj@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 17 Jun 2026 15:15:50 +0000 Message-Id: <20260617151550.E28B01F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: Pre-existing issues: - [High] Missing kobject_del() in damon_sysfs_schemes_add_dirs() error path= causes sysfs name collision -- commit 34de5330acff239aa85773dbe06b9dce6ee27d61 Author: SeongJae Park mm/damon/sysfs-schemes: kobject_del() scheme action destination dirs On CONFIG_DEBUG_KOBJECT_RELEASE enabled kernel, lack of kobject_del() could cause directories creation failures due to the name conflicts. Fix those issues for scheme action destination directories by adding kobject_del() calls. Cc: # 6.17.x > diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c > index 737638be84f15..108f6de32f8c1 100644 > --- a/mm/damon/sysfs-schemes.c > +++ b/mm/damon/sysfs-schemes.c > @@ -2148,8 +2148,10 @@ static void damos_sysfs_dests_rm_dirs( > struct damos_sysfs_dest **dests_arr =3D dests->dests_arr; > int i; > =20 > - for (i =3D 0; i < dests->nr; i++) > + for (i =3D 0; i < dests->nr; i++) { > + kobject_del(&dests_arr[i]->kobj); > kobject_put(&dests_arr[i]->kobj); > + } > dests->nr =3D 0; > kfree(dests_arr); > dests->dests_arr =3D NULL; [Severity: High] This isn't a bug introduced by this patch, but does the out: error path in damon_sysfs_schemes_add_dirs() have a similar issue? If kobject_init_and_add() succeeds for a new scheme but the subsequent damon_sysfs_scheme_add_dirs() call fails, it jumps to the out: label: mm/damon/sysfs-schemes.c:damon_sysfs_schemes_add_dirs() { ... err =3D kobject_init_and_add(&scheme->kobj, &damon_sysfs_scheme_ktype, &schemes->kobj, "%d", i); if (err) goto out; err =3D damon_sysfs_scheme_add_dirs(scheme); if (err) goto out; ... out: damon_sysfs_schemes_rm_dirs(schemes); kobject_put(&scheme->kobj); return err; } Since the failed scheme hasn't been added to schemes_arr yet, damon_sysfs_schemes_rm_dirs() only cleans up the previously added schemes. Then kobject_put() is called on the current scheme without a prior kobject_del(). With CONFIG_DEBUG_KOBJECT_RELEASE enabled, could this omission leave the newly created sysfs directory intact and cause a name collision (-EEXIST) if userspace retries creating the schemes shortly after? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260617144807.9144= 1-1-sj@kernel.org?part=3D7