The DM implementation of spi_flash_free() does not unregister the MTD device before removing the spi dev object. This leads to a use-after-free bug when the MTD device is later accessed by a MTD user (observed when attaching the device to UBI after env_sf_load() has called spi_flash_free()).
Implement ->remove() and call spi_flash_mtd_unregister() from there.
Fixes: 9fe6d8716e09 ("mtd, spi: Add MTD layer driver") Signed-off-by: Boris Brezillon boris.brezillon@bootlin.com Tested-by: Heiko Schocher hs@denx.de Reviewed-by: Jagan Teki jagan@openedev.com --- Changes in v4: - Add T-b/R-b tags
Changes in v3: - New patch --- drivers/mtd/spi/sf_probe.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/mtd/spi/sf_probe.c b/drivers/mtd/spi/sf_probe.c index 5a2e932de8f8..00f8558e7019 100644 --- a/drivers/mtd/spi/sf_probe.c +++ b/drivers/mtd/spi/sf_probe.c @@ -144,6 +144,14 @@ static int spi_flash_std_probe(struct udevice *dev) return spi_flash_probe_slave(flash); }
+static int spi_flash_std_remove(struct udevice *dev) +{ +#ifdef CONFIG_SPI_FLASH_MTD + spi_flash_mtd_unregister(); +#endif + return 0; +} + static const struct dm_spi_flash_ops spi_flash_std_ops = { .read = spi_flash_std_read, .write = spi_flash_std_write, @@ -161,6 +169,7 @@ U_BOOT_DRIVER(spi_flash_std) = { .id = UCLASS_SPI_FLASH, .of_match = spi_flash_std_ids, .probe = spi_flash_std_probe, + .remove = spi_flash_std_remove, .priv_auto_alloc_size = sizeof(struct spi_flash), .ops = &spi_flash_std_ops, };