From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Sakkinen Date: Thu, 23 Mar 2017 15:53:58 +0000 Subject: Re: [PATCH] tpm2: fix off-by-one comparison and out-of-bounds read error Message-Id: <20170323155358.jpotoweghjnl4vjx@intel.com> List-Id: References: <20170320142336.10997-1-colin.king@canonical.com> <20170322114256.pdwg6buj2wkhcooy@intel.com> <20170322131248.GJ32449@mwanda> In-Reply-To: <20170322131248.GJ32449@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dan Carpenter Cc: Colin Ian King , Peter Huewe , Marcel Selhorst , Jason Gunthorpe , tpmdd-devel@lists.sourceforge.net, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org On Wed, Mar 22, 2017 at 04:12:49PM +0300, Dan Carpenter wrote: > On Wed, Mar 22, 2017 at 11:45:37AM +0000, Colin Ian King wrote: > > 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 > > >> > > >> 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 > > >> --- > > >> 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 > > if that's OK with you. > > Reported-by isn't really correct though... We should have a Fixes-from: > tag for squashed fixes. > > regards, > dan carpenter Hmm... Maybe so depending on how you interpret Reported-by but Fixes-from is not something that is used at the moment, is it? /Jarkko