[PATCH AUTOSEL 5.4 055/330] mmc: core: Fix size overflow for mmc partitions

Sasha Levin
2020-09-18T03:11:56Z

From: Bradley Bolen <bradleybolen@gmail.com>

[ Upstream commit f3d7c2292d104519195fdb11192daec13229c219 ]

With large eMMC cards, it is possible to create general purpose
partitions that are bigger than 4GB. The size member of the mmc_part
struct is only an unsigned int which overflows for gp partitions larger
than 4GB. Change this to a u64 to handle the overflow.

Signed-off-by: Bradley Bolen <bradleybolen@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/mmc/core/mmc.c | 9 ++++-----
include/linux/mmc/card.h | 2 +-
2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index b7159e243323b..de14b5845f525 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -297,7 +297,7 @@ static void mmc_manage_enhanced_area(struct mmc_card *card, u8 *ext_csd)
}
}

-static void mmc_part_add(struct mmc_card *card, unsigned int size,
+static void mmc_part_add(struct mmc_card *card, u64 size,
unsigned int part_cfg, char *name, int idx, bool ro,
int area_type)
{
@@ -313,7 +313,7 @@ static void mmc_manage_gp_partitions(struct mmc_card *card, u8 *ext_csd)
{
int idx;
u8 hc_erase_grp_sz, hc_wp_grp_sz;
- unsigned int part_size;
+ u64 part_size;

/*
* General purpose partition feature support --
@@ -343,8 +343,7 @@ static void mmc_manage_gp_partitions(struct mmc_card *card, u8 *ext_csd)
(ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3 + 1]
<< 8) +
ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3];
- part_size *= (size_t)(hc_erase_grp_sz *
- hc_wp_grp_sz);
+ part_size *= (hc_erase_grp_sz * hc_wp_grp_sz);
mmc_part_add(card, part_size << 19,
EXT_CSD_PART_CONFIG_ACC_GP0 + idx,
"gp%d", idx, false,
@@ -362,7 +361,7 @@ static void mmc_manage_gp_partitions(struct mmc_card *card, u8 *ext_csd)
static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
{
int err = 0, idx;
- unsigned int part_size;
+ u64 part_size;
struct device_node *np;
bool broken_hpi = false;

diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index e459b38ef33cc..cf3780a6ccc4b 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -226,7 +226,7 @@ struct mmc_queue_req;
* MMC Physical partitions
*/
struct mmc_part {
- unsigned int size; /* partition size (in bytes) */
+ u64 size; /* partition size (in bytes) */
unsigned int part_cfg; /* partition type */
char name[MAX_MMC_PART_NAME_LEN];
bool force_ro; /* to make boot parts RO by default */
--
2.25.1