From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 C1DD921504D; Wed, 7 May 2025 19:09:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746644971; cv=none; b=OFMT+WbLAicAbOIc7BSEf48UnzhGJBN3EYn4jiQTUNkhdeLHcl8+46Zxix4HhpByR6CvHsvNMvCZi5z+7iPsHeQAugVpEmsokYadXHJg0V/f68GCJt50xwKa9CX/dDEbhgYvTxR35CLG39eQfcW14yjsSN5WNfFtVLimtkqJYTY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746644971; c=relaxed/simple; bh=/boOmsE+v4ZFhossTPNaGwLOKLjaItxUSeFtj4YLxps=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aKWo+ZRaAA5CSpCHa0K5O8V38hwzBz3iwGBOci4fOVR1p7L3RsT0fCKD/S3p7DIWtlOE/Py691H5iu7KC2/+vvEjVtjVIlcFO6I/hkYVuNRgkoZLqUsBjwiE0/LawYqp2uWzYb+X+vD72HIvChv/fbXsHmHJrLvtPasqNACerV0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Q99wA0rC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Q99wA0rC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3209DC4CEE2; Wed, 7 May 2025 19:09:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1746644971; bh=/boOmsE+v4ZFhossTPNaGwLOKLjaItxUSeFtj4YLxps=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q99wA0rC9h4gQstSnidBCe8MhLXqfsj179qfgcTAa7Yag9R0Ych77sjeXFfDm1/R/ nOvEoOzyfYsR7fEWtsxH9xcwxxUD9XgNwQbdnePyKVUVp92+O5mQ1SVucZRVDO9HI6 aMNbAiTdZxcYjHHa381ezWEDl7l6MgBz64FguYkI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Benjamin Marzinski , Mikulas Patocka Subject: [PATCH 6.6 023/129] dm: always update the array size in realloc_argv on success Date: Wed, 7 May 2025 20:39:19 +0200 Message-ID: <20250507183814.470243951@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250507183813.500572371@linuxfoundation.org> References: <20250507183813.500572371@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin Marzinski commit 5a2a6c428190f945c5cbf5791f72dbea83e97f66 upstream. realloc_argv() was only updating the array size if it was called with old_argv already allocated. The first time it was called to create an argv array, it would allocate the array but return the array size as zero. dm_split_args() would think that it couldn't store any arguments in the array and would call realloc_argv() again, causing it to reallocate the initial slots (this time using GPF_KERNEL) and finally return a size. Aside from being wasteful, this could cause deadlocks on targets that need to process messages without starting new IO. Instead, realloc_argv should always update the allocated array size on success. Fixes: a0651926553c ("dm table: don't copy from a NULL pointer in realloc_argv()") Cc: stable@vger.kernel.org Signed-off-by: Benjamin Marzinski Signed-off-by: Mikulas Patocka Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-table.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -500,9 +500,10 @@ static char **realloc_argv(unsigned int gfp = GFP_NOIO; } argv = kmalloc_array(new_size, sizeof(*argv), gfp); - if (argv && old_argv) { - memcpy(argv, old_argv, *size * sizeof(*argv)); + if (argv) { *size = new_size; + if (old_argv) + memcpy(argv, old_argv, *size * sizeof(*argv)); } kfree(old_argv);