Patch "wifi: iwlwifi: mvm: Fix a memory corruption issue" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    wifi: iwlwifi: mvm: Fix a memory corruption issue

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     wifi-iwlwifi-mvm-fix-a-memory-corruption-issue.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 1e77cf2616bd4f72edab7f67441982b252b8f8e7
Author: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Date:   Sun Jul 23 22:24:59 2023 +0200

    wifi: iwlwifi: mvm: Fix a memory corruption issue
    
    [ 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@xxxxxxxxxx>
    Acked-by: Gregory Greenman <gregory.greenman@xxxxxxxxx>
    Link: https://lore.kernel.org/r/23f0ec986ef1529055f4f93dcb3940a6cf8d9a94.1690143750.git.christophe.jaillet@xxxxxxxxxx
    Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
index 887d0789c96c3..2e3c98eaa400c 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
@@ -796,7 +796,7 @@ int iwl_run_init_mvm_ucode(struct iwl_mvm *mvm)
 		mvm->nvm_data->bands[0].n_channels = 1;
 		mvm->nvm_data->bands[0].n_bitrates = 1;
 		mvm->nvm_data->bands[0].bitrates =
-			(void *)((u8 *)mvm->nvm_data->channels + 1);
+			(void *)(mvm->nvm_data->channels + 1);
 		mvm->nvm_data->bands[0].bitrates->hw_value = 10;
 	}