From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794186717; b=VFuwKfk2+dDQ0nxwlKLSYHfSv1xJKfW6FZVOlvxv2kw/FJur0ZLfV9P6xPfs9fcW4Yob 1az6GMGBUn+LQ0+mEYntEqj9OxWikAD4Bbd/NnUjBC+TNFxDQBsiA+GLKmpgYTMkFSTrY KDizbaBxKyTLrTLaxeTUrorR59v26SC2M/6Fl+SOXYPYhuQ8/ZQZm9PumFG8MsENjpFL4 A0v6iXR3CsMgjxAD/rQ4GKm+8NBuFlJPg2HiiRjv78VU/bunYfOCWBl67ivFdR0c+m0Mf AnhIB2emcvntrwmAkPM0VWVJd5oUJZGhRIAcdBO2Zk3p/xMQSlvi4HMsMK3uHDVHPoQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794186717; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=o/wCbh/09eSp9H4AYoNBYdfTFWGi0y3B9a54ugNuxOQ=; b=hMjpNgJ1Vvl+r1O7wt9MtA2lGK5zxmFEnJsATrnNn6YXKGgTFa0ax+cZpGxFmnlY2M69 dYsRSgy+G/PUu+5zQrQq0XeWIsNOFPiJ6fpizTKhy8fluX8m1QSGOZQTXarRZjG0hmsfH 7gjBNDznz4HJCrpwOWbkd5p9B2yukW9P366KzKe7+BEK067TlrvR8pS1/QKv2l+A0qZ7+ XWIFUbwjGdlCLLQXV+hBKTy73aIt4h8TObYRF0UdkKQyrDgbtKYgKgW+Gl6IVjxmmKmcv LUbDSd4AmrwtiLAlpF78uRBVqsmdBOcrAWeLsHgBlnPor2jLrR8wmny/6/tjStfafUw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=nnwgoVg5; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 97873606A31C for ; Mon, 9 Nov 2026 01:11:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=nnwgoVg5 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 114711F008A1; Mon, 9 Nov 2026 01:11:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794186717; bh=o/wCbh/09eSp9H4AYoNBYdfTFWGi0y3B9a54ugNuxOQ=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=nnwgoVg5x1tgpWx+h1ONoK2Vbq9wkF572Y+/RZz2F5RUJV5Er+bH0/Ip6X0xOoorF 17Vid9QGsZm5pI2cXMHsyEAwZzO5J7YukL1ByZyQ6WtEjs3tCfOwykW/+PYuRKJehE ARgy1pgjYkCaX7S0iokUHOhkt9zSssVIDc9UH+pxXl1Fm3KoVdR8z8mqzhp/Oys0JG qtvLCXhZCnl/ssUcEbuhLW3fsNeH15ZiydDBVIfJlltKJYFM7ptZbMU5o+DiiRWMOM 1j8K+DYtwDygI+QZVBAlz+bLF504nk4ccUwJV0UEYvaQuXNF6JoDMw4r9lQHwnpPnp JWoQeLoVJfAMA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 7.3.y] mm/damon/sysfs-schemes: read sysfs_filter->sz_range only once Reply-To: sashiko-reviews@lists.linux.dev To: "SJ Park" Cc: damon@lists.linux.dev In-Reply-To: <20261109005724.87550-1-sj@kernel.org> References: <20261107050434-failed-7.3-af19aff38d6f@kernel.org> <20261109005724.87550-1-sj@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 09 Nov 2026 01:11:56 +0000 X-Mailing-List: damon@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > DAMON sysfs interface reads the user-provided size range arguments for > hugepage_size type DAMOS filter twice. Once for validation, and once > again for assignments to the variable that will be passed to the core > layer. If the user updates the arguments in parallel, an invalid size > range could be passed to the core layer. Avoid it by doing the > assignments first, and then validating the assigned variables before > passing those to the core layer. >=20 > User impact of the bug should be trivial. From the core layer's > perspective, the invalid size range is not really invalid. It just works > as having a weird size range. No critical issues such as a crash or a > leak could happen. And sane users ain't do such parallel arguments update > anyway. If they do, such racy behavior is arguably somewhat expected and > deserved. That said, there is no reason to keep such races. >=20 > Link: https://lore.kernel.org/20260914142327.92510-3-sj@kernel.org > Fixes: ea1f204ba29a ("mm/damon/sysfs-schemes: add files for setting damos= _filter->sz_range") > Signed-off-by: SJ Park > Signed-off-by: Andrew Morton > Cc: Brendan Higgins > Cc: David Gow > Cc: Usama Arif > Cc: > (cherry picked from commit af19aff38d6faea35b10f26cca32d0e54f8aea5e) > Signed-off-by: SJ Park Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261109005724.8755= 0-1-sj@kernel.org?part=3D1