linux-kernel - Re: [PATCH] tpm2: fix off-by-one comparison and out-of-bounds read error

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

Message-ID: <d96bb5c9-e1b3-abe5-2273-fc525dc00190@canonical.com>
Date:   Wed, 22 Mar 2017 11:45:37 +0000
From:   Colin Ian King <colin.king@...onical.com>
To:     Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
Cc:     Peter Huewe <peterhuewe@....de>,
        Marcel Selhorst <tpmdd@...horst.net>,
        Jason Gunthorpe <jgunthorpe@...idianresearch.com>,
        tpmdd-devel@...ts.sourceforge.net, kernel-janitors@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] tpm2: fix off-by-one comparison and out-of-bounds read
 error

On 22/03/17 11:42, Jarkko Sakkinen wrote:
> On Mon, Mar 20, 2017 at 02:23:36PM +0000, Colin King wrote:
>> From: Colin Ian King <colin.king@...onical.com>
>>
>> The comparison of an out of range index into space->context_tbl is
>> off-by-one and should be using >= rather than > in the comparison.
>>
>> Detected by CoverityScan, CID#1419694 ("Out-of-bounds read")
>>
>> Fixes: 849246e7ce9ce ("tpm2: add session handle context saving and restoring to the space code")
>> Signed-off-by: Colin Ian King <colin.king@...onical.com>
>> ---
>>  drivers/char/tpm/tpm2-space.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
>> index d36d81e07076..009934269514 100644
>> --- a/drivers/char/tpm/tpm2-space.c
>> +++ b/drivers/char/tpm/tpm2-space.c
>> @@ -229,7 +229,7 @@ static bool tpm2_map_to_phandle(struct tpm_space *space, void *handle)
>>  	int i;
>>  
>>  	i = 0xFFFFFF - (vhandle & 0xFFFFFF);
>> -	if (i > ARRAY_SIZE(space->context_tbl) || !space->context_tbl[i])
>> +	if (i >= ARRAY_SIZE(space->context_tbl) || !space->context_tbl[i])
>>  		return false;
>>  
>>  	phandle = space->context_tbl[i];
>> -- 
>> 2.11.0
> 
> Thanks. If you don't mind, I would squash this to that patch?
> 
> /Jarkko
> 
Sure squash it, and maybe add a Reported-by: Colin Ian King
<colin.king@...onical.com> if that's OK with you.

Colin