Re: [PATCH] md/raid5: Convert stripe_head's "dev" to flexible array member
From: Christoph Hellwig <hch@infradead.org>
Date: 2023-05-18 04:27:31
Also in:
linux-hardening, lkml
On Wed, May 17, 2023 at 04:33:14PM -0700, Kees Cook wrote:
quoted hunk ↗ jump to hunk
sc = kmem_cache_create(conf->cache_name[conf->active_name], - sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), + struct_size((struct stripe_head *)0, dev, devs), 0, 0, NULL); if (!sc) return 1;@@ -2559,7 +2559,7 @@ static int resize_stripes(struct r5conf *conf, int newsize) /* Step 1 */ sc = kmem_cache_create(conf->cache_name[1-conf->active_name], - sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev), + struct_size((struct stripe_head *)0, dev, newsize),
The constant you're casting here should be NULL, not 0. Also given that this expression is duplicated, I'd suggest a little helper for it…
- } dev[1]; /* allocated with extra space depending of RAID geometry */ + } dev[]; /* allocated with extra space depending of RAID geometry */
And this isn't extra space over the single entry anymore, so I'd change this to: /* allocated depending of RAID geometry */