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 B09FB473C6C; Tue, 21 Jul 2026 22:21:47 +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=1784672508; cv=none; b=H/niuUfYnxO1edCtTJI+D40+OjoX/Rggq7kqxxmhF2V2wTOIpfERkTlFFCYFRAilJv0yMXAzlF+LIudVcws89REAYpZz2LAsa5zgzkRosZR7MbRnIEpKqrkuJb8asH+phTLsYQEWISwUsliJdYtPdTd2e8YCNEYlejo1S3prxxk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784672508; c=relaxed/simple; bh=mfcCFpTAg0zgLCV2hYVNxjZgHGie2Dq78TNOSxuOV2Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rMqO+0nevrsRAqdCSdA0a4jHIsz/dbnRZiETMZNNhSEpnE1SjatD9jWWnWOnvGEUm1CD436RfOSlzGo/7XviNG2tAQnYulIOin9FCz+Rze6ZaqYjdScbd3cxFcfWnmfv4j80WNLPOWY2804ULGu4n9alVsj3W3KfFsWoCmEqyAM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Yvssuj2m; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Yvssuj2m" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 219F51F000E9; Tue, 21 Jul 2026 22:21:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784672507; bh=Fq2F0PCHm/QhsIDZ3EuHjfnWVXqbMfNAGJYS5e74JrM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Yvssuj2mJTvEWGFRtuwhyXndeinHaMgTJJka7JbooUkPC2kW6092pXYmONCAooxkd S6ix1Lstax5ra/Y+3jpCXP999xDmqD8mqtYUWiIfiSqdI0H/4muARkuFxbcqDoysKY JBWDPmAs7kBWT5OQm5BPoGVaDnicbdJ9EUlNP4G8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Genjian Zhang , Mikulas Patocka Subject: [PATCH 5.15 651/843] dm thin metadata: fix superblock refcount leak on snapshot shadow failure Date: Tue, 21 Jul 2026 17:24:46 +0200 Message-ID: <20260721152420.713027173@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152405.946368001@linuxfoundation.org> References: <20260721152405.946368001@linuxfoundation.org> User-Agent: quilt/0.69 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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Genjian Zhang commit 4b22d0801fadfcae2e106e6ba32e49439c7c7ebf upstream. __reserve_metadata_snap() increments THIN_SUPERBLOCK_LOCATION in the metadata space map before shadowing it. When dm_tm_shadow_block() fails, a reference is leaked in the metadata space map. Fix by adding the missing dm_sm_dec_block(). Signed-off-by: Genjian Zhang Signed-off-by: Mikulas Patocka Fixes: cc8394d86f04 ("dm thin: provide userspace access to pool metadata") Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-thin-metadata.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -1331,8 +1331,10 @@ static int __reserve_metadata_snap(struc dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION); r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION, &sb_validator, ©, &inc); - if (r) + if (r) { + dm_sm_dec_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION); return r; + } BUG_ON(!inc);