Commit e004c3e6 authored by Colin Ian King's avatar Colin Ian King Committed by Krzysztof Kozlowski
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memory: gpmc: fix out of bounds read and dereference on gpmc_cs[] 



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: 9ed7a776 ("ARM: OMAP2+: Fix support for multiple devices on a GPMC chip select")
Signed-off-by: default avatarColin Ian King <colin.king@canonical.com>
Reviewed-by: default avatarTony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20210223193821.17232-1-colin.king@canonical.com


Signed-off-by: default avatarKrzysztof Kozlowski <krzk@kernel.org>
parent a38fd874

drivers/memory/omap-gpmc.c

+5 −2
Original line number Diff line number Diff line
@@ -1009,8 +1009,8 @@ 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)) {
@@ -1018,6 +1018,9 @@ 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);