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patches/openwrt: kernel: mwifiex: fix memory corruption

Merged patches/openwrt: kernel: mwifiex: fix memory corruption
hotfix/mwifiex-backport-patch into hbk
Merged Josef Schlehofer requested to merge hotfix/mwifiex-backport-patch into hbk
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patches/openwrt/to-upstream/0034-kernel-backport-fix-for-memory-corruption-in-mwifiex.patch 0 → 100644
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From 6398ad557a574cb8047feedc3d6e71be7b608fa5 Mon Sep 17 00:00:00 2001
From: Josef Schlehofer <pepe.schlehofer@gmail.com>
Date: Fri, 29 May 2020 18:39:21 +0200
Subject: [PATCH] kernel: backport fix for memory corruption in mwifiex
This is already stagged in wireless-next-drivers.
Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>
---
.../900-mwifiex-fix-memory-corruption.patch | 87 +++++++++++++++++++
1 file changed, 87 insertions(+)
create mode 100644 target/linux/generic/backport-4.14/900-mwifiex-fix-memory-corruption.patch
diff --git a/target/linux/generic/backport-4.14/900-mwifiex-fix-memory-corruption.patch b/target/linux/generic/backport-4.14/900-mwifiex-fix-memory-corruption.patch
new file mode 100644
index 0000000000..cf1e47302f
--- /dev/null
+++ b/target/linux/generic/backport-4.14/900-mwifiex-fix-memory-corruption.patch
@@ -0,0 +1,87 @@
+From 3aa42bae9c4d1641aeb36f1a8585cd1d506cf471 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
+Date: Fri, 15 May 2020 09:59:24 +0200
+Subject: mwifiex: Fix memory corruption in dump_station
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+The mwifiex_cfg80211_dump_station() uses static variable for iterating
+over a linked list of all associated stations (when the driver is in UAP
+role). This has a race condition if .dump_station is called in parallel
+for multiple interfaces. This corruption can be triggered by registering
+multiple SSIDs and calling, in parallel for multiple interfaces
+ iw dev <iface> station dump
+
+[16750.719775] Unable to handle kernel paging request at virtual address dead000000000110
+...
+[16750.899173] Call trace:
+[16750.901696] mwifiex_cfg80211_dump_station+0x94/0x100 [mwifiex]
+[16750.907824] nl80211_dump_station+0xbc/0x278 [cfg80211]
+[16750.913160] netlink_dump+0xe8/0x320
+[16750.916827] netlink_recvmsg+0x1b4/0x338
+[16750.920861] ____sys_recvmsg+0x7c/0x2b0
+[16750.924801] ___sys_recvmsg+0x70/0x98
+[16750.928564] __sys_recvmsg+0x58/0xa0
+[16750.932238] __arm64_sys_recvmsg+0x28/0x30
+[16750.936453] el0_svc_common.constprop.3+0x90/0x158
+[16750.941378] do_el0_svc+0x74/0x90
+[16750.944784] el0_sync_handler+0x12c/0x1a8
+[16750.948903] el0_sync+0x114/0x140
+[16750.952312] Code: f9400003 f907f423 eb02007f 54fffd60 (b9401060)
+[16750.958583] ---[ end trace c8ad181c2f4b8576 ]---
+
+This patch drops the use of the static iterator, and instead every time
+the function is called iterates to the idx-th position of the
+linked-list.
+
+It would be better to convert the code not to use linked list for
+associated stations storage (since the chip has a limited number of
+associated stations anyway - it could just be an array). Such a change
+may be proposed in the future. In the meantime this patch can backported
+into stable kernels in this simple form.
+
+Fixes: 8baca1a34d4c ("mwifiex: dump station support in uap mode")
+Signed-off-by: Pali Rohár <pali@kernel.org>
+Acked-by: Ganapathi Bhat <ganapathi.bhat@nxp.com>
+Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
+Link: https://lore.kernel.org/r/20200515075924.13841-1-pali@kernel.org
+---
+ drivers/net/wireless/marvell/mwifiex/cfg80211.c | 14 ++++++--------
+ 1 file changed, 6 insertions(+), 8 deletions(-)
+
+diff --git a/drivers/net/wireless/marvell/mwifiex/cfg80211.c b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
+index 1566d2197906..12bfd653a405 100644
+--- a/drivers/net/wireless/marvell/mwifiex/cfg80211.c
++++ b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
+@@ -1496,7 +1496,8 @@ mwifiex_cfg80211_dump_station(struct wiphy *wiphy, struct net_device *dev,
+ int idx, u8 *mac, struct station_info *sinfo)
+ {
+ struct mwifiex_private *priv = mwifiex_netdev_get_priv(dev);
+- static struct mwifiex_sta_node *node;
++ struct mwifiex_sta_node *node;
++ int i;
+
+ if ((GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA) &&
+ priv->media_connected && idx == 0) {
+@@ -1506,13 +1507,10 @@ mwifiex_cfg80211_dump_station(struct wiphy *wiphy, struct net_device *dev,
+ mwifiex_send_cmd(priv, HOST_CMD_APCMD_STA_LIST,
+ HostCmd_ACT_GEN_GET, 0, NULL, true);
+
+- if (node && (&node->list == &priv->sta_list)) {
+- node = NULL;
+- return -ENOENT;
+- }
+-
+- node = list_prepare_entry(node, &priv->sta_list, list);
+- list_for_each_entry_continue(node, &priv->sta_list, list) {
++ i = 0;
++ list_for_each_entry(node, &priv->sta_list, list) {
++ if (i++ != idx)
++ continue;
+ ether_addr_copy(mac, node->mac_addr);
+ return mwifiex_dump_station_info(priv, node, sinfo);
+ }
+--
+cgit 1.2.3-1.el7
+
--
2.26.2