Thank you for the explanation. The following patch will resolve the issue. Thanks,
>From 2048e7458c982f4297da9d3366ab29224ae2e8b0 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim <jaegeuk....@samsung.com> Date: Fri, 18 Apr 2014 15:21:04 +0900 Subject: [PATCH] f2fs: avoid BUG_ON when mouting corrupted image having garbage blocks If the disk has some garbage blocks, F2FS is able to face with BUG_ON when recovering direct node blocks. This patch detects the error case and avoids that prior to reaching BUG_ON. Alexey Khoroshilov addressed the potential security issues as follows. "An ability to trigger a BUG_ON assert by mounting a crafted image is usually considered as a local denial of service [1-3]. As far as I understand, the reason is that some kernel data may become inconsistent that can lead to further problems. [1] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-3353 [2] http://www.openwall.com/lists/oss-security/2011/06/24/4 [3] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-2928 etc." Reported-by: Andrey Tsyvarev <tsyva...@ispras.ru> Cc: Alexey Khoroshilov <khoroshi...@ispras.ru> Signed-off-by: Jaegeuk Kim <jaegeuk....@samsung.com> --- fs/f2fs/node.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 6ebdba1..64755f4 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1609,6 +1609,11 @@ int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page) struct node_info old_ni, new_ni; struct page *ipage; + get_node_info(sbi, ino, &old_ni); + + if (unlikely(old_ni.blk_addr != NULL_ADDR)) + return -EINVAL; + ipage = grab_cache_page(NODE_MAPPING(sbi), ino); if (!ipage) return -ENOMEM; @@ -1616,7 +1621,6 @@ int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page) /* Should not use this inode from free nid list */ remove_free_nid(NM_I(sbi), ino); - get_node_info(sbi, ino, &old_ni); SetPageUptodate(ipage); fill_node_footer(ipage, ino, ino, 0, true); -- 1.8.4.474.g128a96c -- Jaegeuk Kim Samsung ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/NeoTech _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
