From f44ec6f3f89889a469773b1fd894f8fcc07c29cf Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Tue, 16 Oct 2007 23:27:15 -0700 Subject: [PATCH] limit minixfs printks on corrupted dir i_size This attempts to address CVE-2006-6058 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-6058 first reported at http://projects.info-pull.com/mokb/MOKB-17-11-2006.html Essentially a corrupted minix dir inode reporting a very large i_size will loop for a very long time in minix_readdir, minix_find_entry, etc, because on EIO they just move on to try the next page. This is under the BKL, printk-storming as well. This can lock up the machine for a very long time. Simply ratelimiting the printks gets things back under control. Make the message a bit more informative while we're here. Signed-off-by: Eric Sandeen Cc: Bodo Eggert <7eggert@gmx.de> Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/minix/itree_v1.c | 9 +++++++-- fs/minix/itree_v2.c | 9 +++++++-- 2 files changed, 14 insertions(+), 4 deletions(-) diff --git a/fs/minix/itree_v1.c b/fs/minix/itree_v1.c index 1a5f3bf0bce..82d6554b02f 100644 --- a/fs/minix/itree_v1.c +++ b/fs/minix/itree_v1.c @@ -23,11 +23,16 @@ static inline block_t *i_data(struct inode *inode) static int block_to_path(struct inode * inode, long block, int offsets[DEPTH]) { int n = 0; + char b[BDEVNAME_SIZE]; if (block < 0) { - printk("minix_bmap: block<0\n"); + printk("MINIX-fs: block_to_path: block %ld < 0 on dev %s\n", + block, bdevname(inode->i_sb->s_bdev, b)); } else if (block >= (minix_sb(inode->i_sb)->s_max_size/BLOCK_SIZE)) { - printk("minix_bmap: block>big\n"); + if (printk_ratelimit()) + printk("MINIX-fs: block_to_path: " + "block %ld too big on dev %s\n", + block, bdevname(inode->i_sb->s_bdev, b)); } else if (block < 7) { offsets[n++] = block; } else if ((block -= 7) < 512) { diff --git a/fs/minix/itree_v2.c b/fs/minix/itree_v2.c index ad8f0dec4ef..f2301096936 100644 --- a/fs/minix/itree_v2.c +++ b/fs/minix/itree_v2.c @@ -23,12 +23,17 @@ static inline block_t *i_data(struct inode *inode) static int block_to_path(struct inode * inode, long block, int offsets[DEPTH]) { int n = 0; + char b[BDEVNAME_SIZE]; struct super_block *sb = inode->i_sb; if (block < 0) { - printk("minix_bmap: block<0\n"); + printk("MINIX-fs: block_to_path: block %ld < 0 on dev %s\n", + block, bdevname(sb->s_bdev, b)); } else if (block >= (minix_sb(inode->i_sb)->s_max_size/sb->s_blocksize)) { - printk("minix_bmap: block>big\n"); + if (printk_ratelimit()) + printk("MINIX-fs: block_to_path: " + "block %ld too big on dev %s\n", + block, bdevname(sb->s_bdev, b)); } else if (block < 7) { offsets[n++] = block; } else if ((block -= 7) < 256) { -- 2.20.1