kernel: fix possible mtd NULL pointer dereference

Fixes: cae4d089bc ("kernel: backport mtd dynamic partition patch")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
(cherry picked from commit a5265497a4)
This commit is contained in:
Rafał Miłecki 2022-10-04 12:04:37 +02:00
parent 562894b39d
commit 977f6f36a0
4 changed files with 33 additions and 3 deletions

View file

@ -0,0 +1,30 @@
From 7ec4cdb321738d44ae5d405e7b6ac73dfbf99caa Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Mon, 25 Jul 2022 22:49:25 +0900
Subject: [PATCH] mtd: core: check partition before dereference
syzbot is reporting NULL pointer dereference at mtd_check_of_node() [1],
for mtdram test device (CONFIG_MTD_MTDRAM) is not partition.
Link: https://syzkaller.appspot.com/bug?extid=fe013f55a2814a9e8cfd [1]
Reported-by: syzbot <syzbot+fe013f55a2814a9e8cfd@syzkaller.appspotmail.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: ad9b10d1eaada169 ("mtd: core: introduce of support for dynamic partitions")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
CC: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
---
drivers/mtd/mtdcore.c | 2 ++
1 file changed, 2 insertions(+)
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -574,6 +574,8 @@ static void mtd_check_of_node(struct mtd
return;
/* Check if a partitions node exist */
+ if (!mtd_is_partition(mtd))
+ return;
parent = mtd->parent;
parent_dn = dev_of_node(&parent->dev);
if (!parent_dn)

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@ -77,7 +77,7 @@ Signed-off-by: Daniel Golle <daniel@makrotopia.org>
#include "mtdcore.h"
@@ -922,6 +923,8 @@ int mtd_device_parse_register(struct mtd
@@ -924,6 +925,8 @@ int mtd_device_parse_register(struct mtd
register_reboot_notifier(&mtd->reboot_notifier);
}

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@ -20,7 +20,7 @@ Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
#include <linux/nvmem-provider.h>
#include <linux/mtd/mtd.h>
@@ -765,6 +766,19 @@ int add_mtd_device(struct mtd_info *mtd)
@@ -767,6 +768,19 @@ int add_mtd_device(struct mtd_info *mtd)
of this try_ nonsense, and no bitching about it
either. :) */
__module_get(THIS_MODULE);

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@ -17,7 +17,7 @@ Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -1145,6 +1145,44 @@ out_unlock:
@@ -1147,6 +1147,44 @@ out_unlock:
}
EXPORT_SYMBOL_GPL(get_mtd_device_nm);