linux-kernel - Re: [PATCH v2 3/3] dm-pcache: zero cache

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <b24702f2-ea70-4c45-b0a9-dae9cc6104a3@linux.dev>
Date: Thu, 13 Nov 2025 14:40:19 +0800
From: Dongsheng Yang <dongsheng.yang@...ux.dev>
To: Li Chen <me@...ux.beauty>, dm-devel@...ts.linux.dev,
 linux-kernel@...r.kernel.org, Zheng Gu <cengku@...il.com>
Subject: Re: [PATCH v2 3/3] dm-pcache: zero cache_info before default init


在 11/11/2025 8:13 PM, Li Chen 写道:
> From: Li Chen <chenl311@...natelecom.cn>
>
> pcache_meta_find_latest() leaves whatever it last copied into the
> caller’s buffer even when it returns NULL. For cache_info_init(),
> that meant cache->cache_info could still contain CRC-bad garbage when
> no valid metadata exists, leading later initialization paths to read
> bogus flags.
>
> Explicitly memset cache->cache_info in cache_info_init_default()
> so new-cache paths start from a clean slate. The default sequence
> number assignment becomes redundant with this reset, so it drops out.
>
> Signed-off-by: Li Chen <chenl311@...natelecom.cn>

Reviewed-by： Dongsheng Yang <dongsheng.yang@...ux.dev>

> ---
>   drivers/md/dm-pcache/cache.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/md/dm-pcache/cache.c b/drivers/md/dm-pcache/cache.c
> index d516d4904227..698697a7a73c 100644
> --- a/drivers/md/dm-pcache/cache.c
> +++ b/drivers/md/dm-pcache/cache.c
> @@ -181,7 +181,7 @@ static void cache_info_init_default(struct pcache_cache *cache)
>   {
>   	struct pcache_cache_info *cache_info = &cache->cache_info;
>   
> -	cache_info->header.seq = 0;
> +	memset(cache_info, 0, sizeof(*cache_info));
>   	cache_info->n_segs = cache->cache_dev->seg_num;
>   	cache_info_set_gc_percent(cache_info, PCACHE_CACHE_GC_PERCENT_DEFAULT);
>   }