From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Jianpeng Ma , NeilBrown Subject: [ 25/56] md: Avoid write invalid address if read_seqretry returned true. Date: Fri, 30 Nov 2012 10:55:17 -0800 Message-Id: <20121130185120.834782969@linuxfoundation.org> In-Reply-To: <20121130185118.302752929@linuxfoundation.org> References: <20121130185118.302752929@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: majianpeng commit 35f9ac2dcec8f79d7059ce174fd7b7ee3290d620 upstream. If read_seqretry returned true and bbp was changed, it will write invalid address which can cause some serious problem. This bug was introduced by commit v3.0-rc7-130-g2699b67. So fix is suitable for 3.0.y thru 3.6.y. Reported-by: zhuwenfeng@kedacom.com Tested-by: zhuwenfeng@kedacom.com Signed-off-by: Jianpeng Ma Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- drivers/md/md.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -1805,10 +1805,10 @@ retry: memset(bbp, 0xff, PAGE_SIZE); for (i = 0 ; i < bb->count ; i++) { - u64 internal_bb = *p++; + u64 internal_bb = p[i]; u64 store_bb = ((BB_OFFSET(internal_bb) << 10) | BB_LEN(internal_bb)); - *bbp++ = cpu_to_le64(store_bb); + bbp[i] = cpu_to_le64(store_bb); } bb->changed = 0; if (read_seqretry(&bb->lock, seq))