From: Eric Sandeen Date: Wed, 17 Oct 2007 06:27:15 +0000 (-0700) Subject: minixfs: limit minixfs printks on corrupted dir i_size (CVE-2006-6058) X-Git-Tag: v2.6.23.7~3 X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Fstable%2Flinux-2.6.23.y.git;a=commitdiff_plain;h=f0ae3188daf70ed07a4dfbeb133bef3a92838a15 minixfs: limit minixfs printks on corrupted dir i_size (CVE-2006-6058) patch f44ec6f3f89889a469773b1fd894f8fcc07c29cf upstream. 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 Signed-off-by: Greg Kroah-Hartman --- Backported to Debian's 2.6.18 by dann frazier diff -urpN linux-source-2.6.18.orig/fs/minix/itree_v1.c linux-source-2.6.18/fs/minix/itree_v1.c --- linux-source-2.6.18.orig/fs/minix/itree_v1.c 2006-09-19 21:42:06.000000000 -0600 +++ linux-source-2.6.18/fs/minix/itree_v1.c 2007-12-16 19:13:41.000000000 -0700 @@ -23,11 +23,16 @@ static inline block_t *i_data(struct ino 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 -urpN linux-source-2.6.18.orig/fs/minix/itree_v2.c linux-source-2.6.18/fs/minix/itree_v2.c --- linux-source-2.6.18.orig/fs/minix/itree_v2.c 2006-09-19 21:42:06.000000000 -0600 +++ linux-source-2.6.18/fs/minix/itree_v2.c 2007-12-16 19:40:06.000000000 -0700 @@ -23,11 +23,17 @@ static inline block_t *i_data(struct ino 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/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(sb->s_bdev, b)); } else if (block < 7) { offsets[n++] = block; } else if ((block -= 7) < 256) {