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=1793211841; b=NJ5uqO4Pn77mcekb8iKvt5vGAhG+cw1HH3zhELt0b2yPGFOESzbCBibgjSVn7WDVYmDa aoS6+liDSLGnXKBiVtnq514HdLSVnJTQ6czWvEf3sePz+ApeGkd3U3JL2/Vl8sl5+hcJF wXsGVoRXdZPIx/2qm3qb2cXfAJ4L/KLSVJBnYXZ4oT9ZVnNhGI+du4nzIv03rnXVayyO8 wcgfqicP20IXlHbbwMI5lbqdvtvTP748iiEJdKlW/QsdUCoAiKjxcx65mgZSrvUl8ui9h u7x6iPyptEr2yh3OuHB4PRkwu7lW0PTx+fvP9fRRT5QvPhSp43qIWBNqST12VOA/gDw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793211841; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=t9pNGdW6TjfHMTFVMNNSGeHkcxDYQ79vXnt9mex71Ik=; b=gL3XIa7YtK+Z6sc8BmmrBDogSQ8DEYbqlRAgvjQcr7yJjturT4MwkiZR2OouzUiKqo38 O80Fhd2DZoRi/C2rUTq91CZeyfgq5Wza+QdDWCRPaAIA0qVAf6VwG5QhCQJYo6Bd5Amxe PEiPP2AHdXQfIEw6baczTuh6Q9htAmYgty/xobi4ixVJaY4f6lgCJxOcFKXjgrD7SlPB1 x6bw6ZZVd1LXDkg5KaVbSaVcWrx32dqrKPejuiPVRuXPb4ngTDarxHOrxRM5W8RNs4G2X fjxCyf4TLJWC2jlqy2ZftQ3g/zU2gWSrAUWvAIaULXjvWd+VvMztNP1O0vFtnv+aR6Q== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=YVc3UuLT; 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 1B253606A329; Wed, 28 Oct 2026 18:24:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=YVc3UuLT Received: by smtp.kernel.org (Postfix) with ESMTPSA id 975861F01828; Wed, 28 Oct 2026 18:24:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793211841; bh=t9pNGdW6TjfHMTFVMNNSGeHkcxDYQ79vXnt9mex71Ik=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=YVc3UuLTBMrEII0uGicV/SmADI7INtElRdX8Aybe4/8dXuofnpjAB8NVGdOvn9MOR pOQqokMgUSNYHJIn+EqVEBvPaatK8+mnf/2RawxVaZqsbh/io3xDeMDhyO8IhtaNuK sE+GiiLOTsjgQKvPaXZSH5muY+sNqXfX06wQw4uE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Jose Fernandez (Anthropic)" , Ben Cressey , Mikulas Patocka Subject: [PATCH 5.15 512/571] dm-crypt: fix a tiny race condition in crypt_dec_pending Date: Wed, 28 Oct 2026 18:00:59 +0100 Message-ID: <20261028170020.178951174@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170008.009143722@linuxfoundation.org> References: <20261028170008.009143722@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ben Cressey commit 148845aa1921d95ef5dc851c76e6a284f6657df6 upstream. crypt_dec_pending reads io->error before calling atomic_dec_and_test. Another context, for example crypt_endio called from an interrupt, may set io->error and drop its reference between the read and the decrement. crypt_dec_pending then drops the last reference and completes the bio with the stale status - so a read that failed and was never decrypted, or a write that failed, is reported as successful. The read was placed before the decrement by commit b35f8caa0890 ("dm crypt: wait for endio to complete before destruction"), because that commit freed dm_crypt_io before calling bio_endio. This is no longer the case, dm_crypt_io lives in the per-bio data now. Read io->error after atomic_dec_and_test instead. atomic_dec_and_test is fully ordered, so no additional barrier is needed. Fixes: b35f8caa0890 ("dm crypt: wait for endio to complete before destruction") Cc: stable@vger.kernel.org Reviewed-by: Jose Fernandez (Anthropic) Signed-off-by: Ben Cressey Assisted-by: Claude:unspecified Signed-off-by: Mikulas Patocka Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-crypt.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1740,7 +1740,6 @@ static void crypt_dec_pending(struct dm_ { struct crypt_config *cc = io->cc; struct bio *base_bio = io->base_bio; - blk_status_t error = io->error; if (!atomic_dec_and_test(&io->io_pending)) return; @@ -1753,7 +1752,7 @@ static void crypt_dec_pending(struct dm_ else kfree(io->integrity_metadata); - base_bio->bi_status = error; + base_bio->bi_status = io->error; bio_endio(base_bio); }