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 097F94DAF8A; Fri, 9 Oct 2026 14:14:02 +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=1791555248; cv=none; b=lLADfuPl7uoQeADkpkh9GvTMnxv/YdQjhOBJYfcvBZoWTu9YAi0b9coZKGS7W/BS4Aw50hgLIhz0a20YrV5hFExXwB7k2zvjCJ3lD7mAHFsRl1PqhZYHOtV0m3bV+/lzdMyUk0XMhffLcrxQqueusF5lQyDG4/vhHO7AbF9azdw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791555248; c=relaxed/simple; bh=z4wUdky3InbRf4JyzXz1BmgndHxxDAeu8gnzm7Zu7fk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=m8BZZXF2fVVCDd+CdZ5l0tOAKu8IOdNcT8kMdcRLMcWcj4UkjuIlDYgfG7VI3NW6lTfug6xnQFJENYXwM0NMeQXzJ8hnQ+4MxH5QfRAcI9jFtVKLR9XW8pGl5ARvvXxjWJ3V57SKUb8+6azcthz95fWvE4QotgCD0BIMythgX7Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=aO5mgxrq; 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="aO5mgxrq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 854621F00898; Fri, 9 Oct 2026 14:14:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791555242; bh=PUaLnJA2kNOYsWHU/T3U/FVlI0PkVgF+Xu4KhWpDKm4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=aO5mgxrqMXPFpFNYUldO/D3yxkqTD369Omul24euuJo9xP/OavW4xsypKim1+aSv8 0F4V3YvT2oGOA3YxZ72tiChs8YpM0HDKrhaLiyh5pzCwZQ7eI0AWTlRukhaHlh5932 maNb7f+rOszR9ub9eIuBxnbL1YfDTI6mg24kGp8A= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bryam Vargas , Mikulas Patocka , Sasha Levin Subject: [PATCH 7.2 001/428] dm-pcache: reject a kset that overruns its segment Date: Fri, 9 Oct 2026 16:05:38 +0200 Message-ID: <20261009140946.049886099@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261009140946.008206689@linuxfoundation.org> References: <20261009140946.008206689@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 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bryam Vargas [ Upstream commit 7ac1f10f987a2ffae4aecf0e2ceca8f552b665cb ] cache_replay(), the writeback worker and the GC worker read a kset of get_kset_onmedia_size() bytes and advance the position by it. A forged key_num makes that size exceed the segment's remaining space, so the advance walks past the segment and trips the cache_pos_advance() BUG_ON. Reject a kset whose on-media size exceeds cache_seg_remain() before use. Fixes: 1d57628ff95b ("dm-pcache: add persistent cache target in device-mapper") Cc: stable@vger.kernel.org Signed-off-by: Bryam Vargas Signed-off-by: Mikulas Patocka Signed-off-by: Sasha Levin --- drivers/md/dm-pcache/cache_gc.c | 5 +++++ drivers/md/dm-pcache/cache_key.c | 5 +++++ drivers/md/dm-pcache/cache_writeback.c | 5 +++++ 3 files changed, 15 insertions(+) diff --git a/drivers/md/dm-pcache/cache_gc.c b/drivers/md/dm-pcache/cache_gc.c index a167892be7cef..d551848912b45 100644 --- a/drivers/md/dm-pcache/cache_gc.c +++ b/drivers/md/dm-pcache/cache_gc.c @@ -146,6 +146,11 @@ void pcache_cache_gc_fn(struct work_struct *work) continue; } + if (get_kset_onmedia_size(kset_onmedia) > cache_seg_remain(&key_tail)) { + atomic_inc(&cache->gc_errors); + return; + } + for (i = 0; i < kset_onmedia->key_num; i++) { struct pcache_cache_key key_tmp = { 0 }; diff --git a/drivers/md/dm-pcache/cache_key.c b/drivers/md/dm-pcache/cache_key.c index a0d109f85504d..61a71876ca1d1 100644 --- a/drivers/md/dm-pcache/cache_key.c +++ b/drivers/md/dm-pcache/cache_key.c @@ -822,6 +822,11 @@ int cache_replay(struct pcache_cache *cache) } /* Replay the kset and check for errors. */ + if (get_kset_onmedia_size(kset_onmedia) > cache_seg_remain(pos)) { + ret = -EIO; + goto out; + } + ret = kset_replay(cache, kset_onmedia); if (ret) goto out; diff --git a/drivers/md/dm-pcache/cache_writeback.c b/drivers/md/dm-pcache/cache_writeback.c index c34db79fcefb4..c8a4c8110a581 100644 --- a/drivers/md/dm-pcache/cache_writeback.c +++ b/drivers/md/dm-pcache/cache_writeback.c @@ -261,6 +261,11 @@ void cache_writeback_fn(struct work_struct *work) goto queue_work; } + if (get_kset_onmedia_size(kset_onmedia) > cache_seg_remain(&dirty_tail)) { + atomic_inc(&cache->writeback_errors); + goto unlock; + } + ret = cache_kset_insert_tree(cache, kset_onmedia); if (ret) { atomic_inc(&cache->writeback_errors); -- 2.53.0