mtd: spi-nor: Fix shift-out-of-bounds in spi_nor_set_erase_type

commit f0f0cfdc3a024e21161714f2e05f0df3b84d42ad upstream.

spi_nor_set_erase_type() was used either to set or to mask out an erase
type. When we used it to mask out an erase type a shift-out-of-bounds
was hit:
UBSAN: shift-out-of-bounds in drivers/mtd/spi-nor/core.c:2237:24
shift exponent 4294967295 is too large for 32-bit type 'int'

The setting of the size_{shift, mask} and of the opcode are unnecessary
when the erase size is zero, as throughout the code just the erase size
is considered to determine whether an erase type is supported or not.
Setting the opcode to 0xFF was wrong too as nobody guarantees that 0xFF
is an unused opcode. Thus when masking out an erase type, just set the
erase size to zero. This will fix the shift-out-of-bounds.

Fixes: 5390a8df769e ("mtd: spi-nor: add support to non-uniform SFDP SPI NOR flash memories")
Cc: stable@vger.kernel.org
Reported-by: Alexander Stein <Alexander.Stein@tq-group.com>
Signed-off-by: Louis Rannou <lrannou@baylibre.com>
Tested-by: Alexander Stein <Alexander.Stein@tq-group.com>
Link: https://lore.kernel.org/r/20230203070754.50677-1-tudor.ambarus@linaro.org
[ta: refine changes, new commit message, fix compilation error]
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 5dbf52aa03551b55c0083cb1599418cfc0a9e3c6..cda57cb86308947ac846bc9bf8002e7cf92a2d83 100644 (file)
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -2003,6 +2003,15 @@ void spi_nor_set_erase_type(struct spi_nor_erase_type *erase, u32 size,
        erase->size_mask = (1 << erase->size_shift) - 1;
 }
 
+/**
+ * spi_nor_mask_erase_type() - mask out a SPI NOR erase type
+ * @erase:     pointer to a structure that describes a SPI NOR erase type
+ */
+void spi_nor_mask_erase_type(struct spi_nor_erase_type *erase)
+{
+       erase->size = 0;
+}
+
 /**
  * spi_nor_init_uniform_erase_map() - Initialize uniform erase map
  * @map:               the erase map of the SPI NOR

diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index 85b0cf254e9746ee3e51f6100e927980ade4ded8..d18dafeb020abb0dab207fda277dc9a66696f8b3 100644 (file)
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -682,6 +682,7 @@ void spi_nor_set_pp_settings(struct spi_nor_pp_command *pp, u8 opcode,
 
 void spi_nor_set_erase_type(struct spi_nor_erase_type *erase, u32 size,
                            u8 opcode);
+void spi_nor_mask_erase_type(struct spi_nor_erase_type *erase);
 struct spi_nor_erase_region *
 spi_nor_region_next(struct spi_nor_erase_region *region);
 void spi_nor_init_uniform_erase_map(struct spi_nor_erase_map *map,

diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
index 681e5e78724ca400d2b7bab6b4c918161a1c47e6..78110387be0b5434252c98eefd9a4a29576fba67 100644 (file)
--- a/drivers/mtd/spi-nor/sfdp.c
+++ b/drivers/mtd/spi-nor/sfdp.c
@@ -876,7 +876,7 @@ static int spi_nor_init_non_uniform_erase_map(struct spi_nor *nor,
         */
        for (i = 0; i < SNOR_ERASE_TYPE_MAX; i++)
                if (!(regions_erase_type & BIT(erase[i].idx)))
-                       spi_nor_set_erase_type(&erase[i], 0, 0xFF);
+                       spi_nor_mask_erase_type(&erase[i]);
 
        return 0;
 }
@@ -1090,7 +1090,7 @@ static int spi_nor_parse_4bait(struct spi_nor *nor,
                        erase_type[i].opcode = (dwords[1] >>
                                                erase_type[i].idx * 8) & 0xFF;
                else
-                       spi_nor_set_erase_type(&erase_type[i], 0u, 0xFF);
+                       spi_nor_mask_erase_type(&erase_type[i]);
        }
 
        /*