lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <1495687820-30692-1-git-send-email-yamada.masahiro@socionext.com>
Date:   Thu, 25 May 2017 13:50:20 +0900
From:   Masahiro Yamada <yamada.masahiro@...ionext.com>
To:     linux-mtd@...ts.infradead.org
Cc:     Masahiro Yamada <yamada.masahiro@...ionext.com>,
        Cyrille Pitchen <cyrille.pitchen@...ev4u.fr>,
        linux-kernel@...r.kernel.org,
        Boris Brezillon <boris.brezillon@...e-electrons.com>,
        Marek Vasut <marek.vasut@...il.com>,
        Brian Norris <computersforpeace@...il.com>,
        Richard Weinberger <richard@....at>,
        David Woodhouse <dwmw2@...radead.org>
Subject: [PATCH] mtd: nand: check ecc->total sanity in nand_scan_tail

Drivers are supposed to set correct ecc->{size,strength,bytes} before
calling nand_scan_tail(), but it does not complain about ecc->total
bigger than oobsize.

In this case, chip->scan_bbt() crashes due to memory corruption, but
it is hard to debug.  It would be kind to fail it earlier with a clear
message.

Signed-off-by: Masahiro Yamada <yamada.masahiro@...ionext.com>
---

I was actually hit by this case.

I wasted half a day until I figured out my coding mistake in my
Denali driver.  It will be helpful to check this in NAND core.


 drivers/mtd/nand/nand_base.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index f4d686192717..14d6a5aa3ee8 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -4970,6 +4970,11 @@ int nand_scan_tail(struct mtd_info *mtd)
 		goto err_free;
 	}
 	ecc->total = ecc->steps * ecc->bytes;
+	if (ecc->total > mtd->oobsize) {
+		WARN(1, "Total number of ECC bytes exceeded oobsize\n");
+		ret = -EINVAL;
+		goto err_free;
+	}
 
 	/*
 	 * The number of bytes available for a client to place data into
-- 
2.7.4

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ