From: Eric Whitney Subject: [PATCH] libext2fs: fix inode cache overruns Date: Sat, 17 Nov 2012 13:37:45 -0500 Message-ID: <20121117183745.GA8489@wallace> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: tytso@mit.edu To: linux-ext4@vger.kernel.org Return-path: Received: from mail-qa0-f53.google.com ([209.85.216.53]:64082 "EHLO mail-qa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751996Ab2KQShu (ORCPT ); Sat, 17 Nov 2012 13:37:50 -0500 Received: by mail-qa0-f53.google.com with SMTP id k31so2514228qat.19 for ; Sat, 17 Nov 2012 10:37:49 -0800 (PST) Content-Disposition: inline Sender: linux-ext4-owner@vger.kernel.org List-ID: An inode cache slot will be overrun if a caller to ext2fs_read_inode_full() or ext2fs_write_inode_full() attempts to read or write a full sized 156 byte inode when the target filesystem contains 128 byte inodes. Limit the copied inode to the smaller of the target filesystem's or the caller's requested inode size. Signed-off-by: Eric Whitney --- lib/ext2fs/inode.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/lib/ext2fs/inode.c b/lib/ext2fs/inode.c index 0ea210e..e47d664 100644 --- a/lib/ext2fs/inode.c +++ b/lib/ext2fs/inode.c @@ -582,7 +582,8 @@ errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino, /* Check to see if it's in the inode cache */ for (i = 0; i < fs->icache->cache_size; i++) { if (fs->icache->cache[i].ino == ino) { - memcpy(inode, fs->icache->cache[i].inode, bufsize); + memcpy(inode, fs->icache->cache[i].inode, + (bufsize > length) ? length : bufsize); return 0; } } @@ -649,7 +650,7 @@ errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino, /* Update the inode cache bookkeeping */ fs->icache->cache_last = cache_slot; fs->icache->cache[cache_slot].ino = ino; - memcpy(inode, iptr, bufsize); + memcpy(inode, iptr, (bufsize > length) ? length : bufsize); return 0; } @@ -705,7 +706,7 @@ errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino, for (i=0; i < fs->icache->cache_size; i++) { if (fs->icache->cache[i].ino == ino) { memcpy(fs->icache->cache[i].inode, inode, - bufsize); + (bufsize > length) ? length : bufsize); break; } } -- 1.7.10.4