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

[Colin King <colin.king-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>]

From: Colin Ian King <colin.king-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>

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-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
---
 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


------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot