[RFC/PATCH RESEND -next 20/21] fs: dcache: manually unpoison dname after allocation to shut up kasan's reports
From: Joonsoo Kim <hidden>
Date: 2014-07-15 06:06:22
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linux-kbuild, linux-mm, lkml
On Wed, Jul 09, 2014 at 03:30:14PM +0400, Andrey Ryabinin wrote:
We need to manually unpoison rounded up allocation size for dname to avoid kasan's reports in __d_lookup_rcu. __d_lookup_rcu may validly read a little beyound allocated size.
If it read a little beyond allocated size, IMHO, it is better to allocate correct size. kmalloc(name->len + 1, GFP_KERNEL); --> kmalloc(roundup(name->len + 1, sizeof(unsigned long ), GFP_KERNEL); Isn't it? Thanks.
quoted hunk ↗ jump to hunk
Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrey Ryabinin <redacted> --- fs/dcache.c | 3 +++ 1 file changed, 3 insertions(+)diff --git a/fs/dcache.c b/fs/dcache.c index b7e8b20..dff64f2 100644 --- a/fs/dcache.c +++ b/fs/dcache.c@@ -38,6 +38,7 @@ #include <linux/prefetch.h> #include <linux/ratelimit.h> #include <linux/list_lru.h> +#include <linux/kasan.h> #include "internal.h" #include "mount.h"@@ -1412,6 +1413,8 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name) kmem_cache_free(dentry_cache, dentry); return NULL; } + unpoison_shadow(dname, + roundup(name->len + 1, sizeof(unsigned long))); } else { dname = dentry->d_iname; }-- 1.8.5.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo at kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email at kvack.org </a>