linux-kernel - [PATCH 5.4/5.10 1/1] wifi: iwlwifi: mvm: Fix a memory corruption issue

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: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20241129125813.25555-2-n.zhandarovich@fintech.ru>
Date: Fri, 29 Nov 2024 04:58:13 -0800
From: Nikita Zhandarovich <n.zhandarovich@...tech.ru>
To: <stable@...r.kernel.org>, Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Sasha Levin <sashal@...nel.org>
CC: Nikita Zhandarovich <n.zhandarovich@...tech.ru>, Luca Coelho
	<luciano.coelho@...el.com>, Kalle Valo <kvalo@...eaurora.org>, "David S.
 Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>, "Johannes
 Berg" <johannes.berg@...el.com>, Christophe JAILLET
	<christophe.jaillet@...adoo.fr>, <linux-wireless@...r.kernel.org>,
	<netdev@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<lvc-project@...uxtesting.org>
Subject: [PATCH 5.4/5.10 1/1] wifi: iwlwifi: mvm: Fix a memory corruption issue

From: Christophe JAILLET <christophe.jaillet@...adoo.fr>

[ Upstream commit 8ba438ef3cacc4808a63ed0ce24d4f0942cfe55d ]

A few lines above, space is kzalloc()'ed for:
	sizeof(struct iwl_nvm_data) +
	sizeof(struct ieee80211_channel) +
	sizeof(struct ieee80211_rate)

'mvm->nvm_data' is a 'struct iwl_nvm_data', so it is fine.

At the end of this structure, there is the 'channels' flex array.
Each element is of type 'struct ieee80211_channel'.
So only 1 element is allocated in this array.

When doing:
  mvm->nvm_data->bands[0].channels = mvm->nvm_data->channels;
We point at the first element of the 'channels' flex array.
So this is fine.

However, when doing:
  mvm->nvm_data->bands[0].bitrates =
			(void *)((u8 *)mvm->nvm_data->channels + 1);
because of the "(u8 *)" cast, we add only 1 to the address of the beginning
of the flex array.

It is likely that we want point at the 'struct ieee80211_rate' allocated
just after.

Remove the spurious casting so that the pointer arithmetic works as
expected.

Fixes: 8ca151b568b6 ("iwlwifi: add the MVM driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@...adoo.fr>
Acked-by: Gregory Greenman <gregory.greenman@...el.com>
Link: https://lore.kernel.org/r/23f0ec986ef1529055f4f93dcb3940a6cf8d9a94.1690143750.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Johannes Berg <johannes.berg@...el.com>
[Nikita: no cast to (u8 *) is present in older kernels so just
ensure that (void *) cast is used on a modified channels pointer
rather than incrementing (void *) pointer after.]
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@...tech.ru>
---
 drivers/net/wireless/intel/iwlwifi/mvm/fw.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
index 287f9c551525..c3d7d0e06c87 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
@@ -653,7 +653,7 @@ int iwl_run_init_mvm_ucode(struct iwl_mvm *mvm, bool read_nvm)
 		mvm->nvm_data->bands[0].n_channels = 1;
 		mvm->nvm_data->bands[0].n_bitrates = 1;
 		mvm->nvm_data->bands[0].bitrates =
-			(void *)mvm->nvm_data->channels + 1;
+			(void *)(mvm->nvm_data->channels + 1);
 		mvm->nvm_data->bands[0].bitrates->hw_value = 10;
 	}
 
-- 
2.25.1