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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Johannes Berg <johannes.berg@intel.com>,
	Golan Ben-Ami <golan.ben.ami@intel.com>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>,
	Luca Coelho <luciano.coelho@intel.com>,
	Intel Linux Wireless <linuxwifi@intel.com>,
	Kalle Valo <kvalo@codeaurora.org>,
	Sara Sharon <sara.sharon@intel.com>, Ido Yariv <ido@wizery.com>,
	linux-wireless@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH] iwlwifi: mvm: writing zero bytes to debugfs causes a crash
Date: Thu, 23 Mar 2017 10:40:00 +0000	[thread overview]
Message-ID: <20170323104000.GB20154@mwanda> (raw)

This is a static analysis fix.  The warning is:

	drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c:912 iwl_mvm_fw_dbg_collect()
	warn: integer overflows 'sizeof(*desc) + len'

I guess this code is supposed to take a NUL character, but if we write
zero bytes then it tries to write -1 characters and crashes.

Fixes: c91b865cb14d ("iwlwifi: mvm: support description for user triggered fw dbg collection")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/debugfs.c b/drivers/net/wireless/intel/iwlwifi/mvm/debugfs.c
index a260cd503200..077bfd8f4c0c 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/debugfs.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/debugfs.c
@@ -1056,6 +1056,8 @@ static ssize_t iwl_dbgfs_fw_dbg_collect_write(struct iwl_mvm *mvm,
 
 	if (ret)
 		return ret;
+	if (count = 0)
+		return 0;
 
 	iwl_mvm_fw_dbg_collect(mvm, FW_DBG_TRIGGER_USER, buf,
 			       (count - 1), NULL);

             reply	other threads:[~2017-03-23 10:40 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-23 10:40 Dan Carpenter [this message]
2017-03-23 12:25 ` [PATCH] iwlwifi: mvm: writing zero bytes to debugfs causes a crash Luca Coelho

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