memory: gpmc: fix out of bounds read and dereference on gpmc_cs[]

[ Upstream commit e004c3e67b6459c99285b18366a71af467d869f5 ]

Currently the array gpmc_cs is indexed by cs before it cs is range checked
and the pointer read from this out-of-index read is dereferenced. Fix this
by performing the range check on cs before the read and the following
pointer dereference.

Addresses-Coverity: ("Negative array index read")
Fixes: 9ed7a776eb ("ARM: OMAP2+: Fix support for multiple devices on a GPMC chip select")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20210223193821.17232-1-colin.king@canonical.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Colin Ian King 2021-02-23 19:38:21 +00:00 committed by Greg Kroah-Hartman
parent 52189bf0b2
commit 12d9d517a2
1 changed files with 5 additions and 2 deletions

View File

@ -1026,8 +1026,8 @@ EXPORT_SYMBOL(gpmc_cs_request);
void gpmc_cs_free(int cs)
{
struct gpmc_cs_data *gpmc = &gpmc_cs[cs];
struct resource *res = &gpmc->mem;
struct gpmc_cs_data *gpmc;
struct resource *res;
spin_lock(&gpmc_mem_lock);
if (cs >= gpmc_cs_num || cs < 0 || !gpmc_cs_reserved(cs)) {
@ -1036,6 +1036,9 @@ void gpmc_cs_free(int cs)
spin_unlock(&gpmc_mem_lock);
return;
}
gpmc = &gpmc_cs[cs];
res = &gpmc->mem;
gpmc_cs_disable_mem(cs);
if (res->flags)
release_resource(res);