From 12d9d517a2fe816a57852cade62fa9dbe09f3461 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Tue, 23 Feb 2021 19:38:21 +0000 Subject: [PATCH] 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: 9ed7a776eb50 ("ARM: OMAP2+: Fix support for multiple devices on a GPMC chip select") Signed-off-by: Colin Ian King Reviewed-by: Tony Lindgren Link: https://lore.kernel.org/r/20210223193821.17232-1-colin.king@canonical.com Signed-off-by: Krzysztof Kozlowski Signed-off-by: Sasha Levin --- drivers/memory/omap-gpmc.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c index 27bc417029e1..332ffd7cf8b0 100644 --- a/drivers/memory/omap-gpmc.c +++ b/drivers/memory/omap-gpmc.c @@ -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);