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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Peng Fan <peng.fan@nxp.com>,
	Mark Brown <broonie@kernel.org>
Subject: [PATCH 4.14 13/14] regmap: debugfs: check count when read regmap file
Date: Thu, 30 Jul 2020 10:04:56 +0200
Message-ID: <20200730074419.551880453@linuxfoundation.org> (raw)
In-Reply-To: <20200730074418.882736401@linuxfoundation.org>

From: Peng Fan <peng.fan@nxp.com>

commit 74edd08a4fbf51d65fd8f4c7d8289cd0f392bd91 upstream.

When executing the following command, we met kernel dump.
dmesg -c > /dev/null; cd /sys;
for i in `ls /sys/kernel/debug/regmap/* -d`; do
	echo "Checking regmap in $i";
	cat $i/registers;
done && grep -ri "0x02d0" *;

It is because the count value is too big, and kmalloc fails. So add an
upper bound check to allow max size `PAGE_SIZE << (MAX_ORDER - 1)`.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/1584064687-12964-1-git-send-email-peng.fan@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/base/regmap/regmap-debugfs.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -204,6 +204,9 @@ static ssize_t regmap_read_debugfs(struc
 	if (*ppos < 0 || !count)
 		return -EINVAL;
 
+	if (count > (PAGE_SIZE << (MAX_ORDER - 1)))
+		count = PAGE_SIZE << (MAX_ORDER - 1);
+
 	buf = kmalloc(count, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
@@ -352,6 +355,9 @@ static ssize_t regmap_reg_ranges_read_fi
 	if (*ppos < 0 || !count)
 		return -EINVAL;
 
+	if (count > (PAGE_SIZE << (MAX_ORDER - 1)))
+		count = PAGE_SIZE << (MAX_ORDER - 1);
+
 	buf = kmalloc(count, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;



  parent reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-30  8:04 [PATCH 4.14 00/14] 4.14.191-rc1 review Greg Kroah-Hartman
2020-07-30  8:04 ` [PATCH 4.14 01/14] AX.25: Fix out-of-bounds read in ax25_connect() Greg Kroah-Hartman
2020-07-30  8:04 ` [PATCH 4.14 02/14] AX.25: Prevent out-of-bounds read in ax25_sendmsg() Greg Kroah-Hartman
2020-07-30  8:04 ` [PATCH 4.14 03/14] dev: Defer free of skbs in flush_backlog Greg Kroah-Hartman
2020-07-30  8:04 ` [PATCH 4.14 04/14] drivers/net/wan/x25_asy: Fix to make it work Greg Kroah-Hartman
2020-07-30  8:04 ` [PATCH 4.14 05/14] net-sysfs: add a newline when printing tx_timeout by sysfs Greg Kroah-Hartman
2020-07-30  8:04 ` [PATCH 4.14 06/14] net: udp: Fix wrong clean up for IS_UDPLITE macro Greg Kroah-Hartman
2020-07-30  8:04 ` [PATCH 4.14 07/14] rxrpc: Fix sendmsg() returning EPIPE due to recvmsg() returning ENODATA Greg Kroah-Hartman
2020-07-30  8:04 ` [PATCH 4.14 08/14] AX.25: Prevent integer overflows in connect and sendmsg Greg Kroah-Hartman
2020-07-30  8:04 ` [PATCH 4.14 09/14] ip6_gre: fix null-ptr-deref in ip6gre_init_net() Greg Kroah-Hartman
2020-07-30  8:04 ` [PATCH 4.14 10/14] rtnetlink: Fix memory(net_device) leak when ->newlink fails Greg Kroah-Hartman
2020-07-30  8:04 ` [PATCH 4.14 11/14] tcp: allow at most one TLP probe per flight Greg Kroah-Hartman
2020-07-30  8:04 ` [PATCH 4.14 12/14] mm/page_owner.c: remove drain_all_pages from init_early_allocated_pages Greg Kroah-Hartman
2020-07-30  8:04 ` Greg Kroah-Hartman [this message]
2020-07-30  8:04 ` [PATCH 4.14 14/14] xfs: set format back to extents if xfs_bmap_extents_to_btree Greg Kroah-Hartman
2020-07-30 16:47 ` [PATCH 4.14 00/14] 4.14.191-rc1 review Guenter Roeck
2020-07-31 12:15 ` Naresh Kamboju
2020-07-31 12:42 ` Jon Hunter

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