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'ing as well. This can lock up the machine for a very long time. A simple approach is to at least limit the nr. of pages attempted to no more than s_max_size. (s_max_size is about 256MB for V1, but 2GB for V2; this could still result in a lot of EIO reads in the V2 case, should the retry loops in minix_readdir & friends be short-circuited somehow instead? A simple "break" rather than "continue" on error would certainly resolve it, too...) Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> --- linux-2.6.22-rc4.orig/fs/minix/dir.c +++ linux-2.6.22-rc4/fs/minix/dir.c @@ -42,7 +42,15 @@ minix_last_byte(struct inode *inode, uns static inline unsigned long dir_pages(struct inode *inode) { - return (inode->i_size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT; + loff_t size = inode->i_size; + + if (size > minix_sb(inode->i_sb)->s_max_size) { + printk("%s: inode %lld i_size > s_max_size\n", + __FUNCTION__, inode->i_size); + size = minix_sb(inode->i_sb)->s_max_size; + } + + return (size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT; } static int dir_commit_chunk(struct page *page, unsigned from, unsigned to) - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
