lkml.org 
[lkml]   [2020]   [Jul]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] fat: Fix fat_ra_init() for data clusters == 0
Date
If data clusters == 0, fat_ra_init() calls the ->ent_blocknr() for the
cluster beyond ->max_clusters.

This checks the limit before initialization to suppress the warning.

Reported-by: syzbot+756199124937b31a9b7e@syzkaller.appspotmail.com
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
---
fs/fat/fatent.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index bbfe18c..f7e3304 100644
--- a/fs/fat/fatent.c 2020-07-11 19:58:41.903092419 +0900
+++ b/fs/fat/fatent.c 2020-07-11 19:58:51.545948758 +0900
@@ -657,6 +657,9 @@ static void fat_ra_init(struct super_blo
unsigned long ra_pages = sb->s_bdi->ra_pages;
unsigned int reada_blocks;

+ if (fatent->entry >= ent_limit)
+ return;
+
if (ra_pages > sb->s_bdi->io_pages)
ra_pages = rounddown(ra_pages, sb->s_bdi->io_pages);
reada_blocks = ra_pages << (PAGE_SHIFT - sb->s_blocksize_bits + 1);
_
\
 
 \ /
  Last update: 2020-07-11 13:28    [W:0.248 / U:0.292 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site