mtd: spi-nor: core: Add erase size check for erase command initialization

stable inclusion
from stable-5.10.20
commit 68ef24e86cf7f3ec63449506bae34d1d7e789935
bugzilla: 50608

--------------------------------

commit 58fa22f6 upstream.

Even if erase type is same as previous region, erase size can be different
if the previous region is overlaid region. Since 'region->size' is assigned
to 'cmd->size' for overlaid region, comparing 'erase->size' and 'cmd->size'
can detect previous overlaid region.

Fixes: 5390a8df ("mtd: spi-nor: add support to non-uniform SFDP SPI NOR flash memories")
Cc: stable@vger.kernel.org
Signed-off-by: NTakahiro Kuwano <Takahiro.Kuwano@infineon.com>
[ta: Add Fixes tag and Cc to stable]
Signed-off-by: NTudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/13d47e8d8991b8a7fd8cc7b9e2a5319c56df35cc.1601612872.git.Takahiro.Kuwano@infineon.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/mtd/spi-nor/core.c

@@ -1364,6 +1364,7 @@ static int spi_nor_init_erase_cmd_list(struct spi_nor *nor,
 			goto destroy_erase_cmd_list;
 
 		if (prev_erase != erase ||
+		    erase->size != cmd->size ||
 		    region->offset & SNOR_OVERLAID_REGION) {
 			cmd = spi_nor_init_erase_cmd(region, erase);
 			if (IS_ERR(cmd)) {