From: Jan Kara Date: Wed, 30 Apr 2008 07:52:33 +0000 (-0700) Subject: isofs: fix access to unallocated memory when reading corrupted filesystem X-Git-Tag: v2.6.26-rc1~315 X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=2deb1acc653cbd5384b107d050d2deba089db2bd;p=linux-2.6-omap-h63xx.git isofs: fix access to unallocated memory when reading corrupted filesystem When a directory on isofs is corrupted, we did not check whether length of the name in a directory entry and the length of the directory entry itself are consistent. This could lead to possible access beyond the end of buffer when the length of the name was too big. Add this sanity check to directory reading code. Signed-off-by: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/fs/isofs/dir.c b/fs/isofs/dir.c index 1ba407c64df..2f0dc5a1463 100644 --- a/fs/isofs/dir.c +++ b/fs/isofs/dir.c @@ -145,6 +145,14 @@ static int do_isofs_readdir(struct inode *inode, struct file *filp, } de = tmpde; } + /* Basic sanity check, whether name doesn't exceed dir entry */ + if (de_len < de->name_len[0] + + sizeof(struct iso_directory_record)) { + printk(KERN_NOTICE "iso9660: Corrupted directory entry" + " in block %lu of inode %lu\n", block, + inode->i_ino); + return -EIO; + } if (first_de) { isofs_normalize_block_and_offset(de, diff --git a/fs/isofs/namei.c b/fs/isofs/namei.c index 344b247bc29..8299889a835 100644 --- a/fs/isofs/namei.c +++ b/fs/isofs/namei.c @@ -111,6 +111,13 @@ isofs_find_entry(struct inode *dir, struct dentry *dentry, dlen = de->name_len[0]; dpnt = de->name; + /* Basic sanity check, whether name doesn't exceed dir entry */ + if (de_len < dlen + sizeof(struct iso_directory_record)) { + printk(KERN_NOTICE "iso9660: Corrupted directory entry" + " in block %lu of inode %lu\n", block, + dir->i_ino); + return 0; + } if (sbi->s_rock && ((i = get_rock_ridge_filename(de, tmpname, dir)))) {