mtd: jedec_probe: fix shift-out-of-bounds UB in JEDEC ID masking

UBSAN reports shift-out-of-bounds in jedec_read_mfr() and jedec_read_id():

  UBSAN: shift-out-of-bounds in drivers/mtd/chips/jedec_probe.c:1924:13
  shift exponent 32 is too large for 32-bit type 'int'
  UBSAN: shift-out-of-bounds in drivers/mtd/chips/jedec_probe.c:1940:12
  shift exponent 32 is too large for 32-bit type 'int'

The JEDEC manufacturer/device ID masking uses:

  (1 << (cfi->device_type * 8)) - 1

When cfi->device_type is 4, this evaluates to 1 << 32. Since the
literal '1' has type int, this is a 32-bit shift and is undefined behavior.

Fix it by using a 64-bit literal (1ULL) so the shift is performed in a 64-bit type.

Co-developed-by: Hui Peng <benquike@gmail.com>
Signed-off-by: Hui Peng <benquike@gmail.com>
Co-developed-by: Zhihao Yao (Zephyr) <zhihao.yao@njit.edu>
Signed-off-by: Zhihao Yao (Zephyr) <zhihao.yao@njit.edu>
Signed-off-by: Chenxi Hou <ch395@njit.edu>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

diff --git a/drivers/mtd/chips/jedec_probe.c b/drivers/mtd/chips/jedec_probe.c
index b285962eee2a92d14ad1d16644a1673363c4e62a..3c631608f6d6ed23418cbd9b15ce21153f12b47d 100644 (file)
--- a/drivers/mtd/chips/jedec_probe.c
+++ b/drivers/mtd/chips/jedec_probe.c
@@ -1921,7 +1921,7 @@ static inline u32 jedec_read_mfr(struct map_info *map, uint32_t base,
         */
        do {
                uint32_t ofs = cfi_build_cmd_addr(0 + (bank << 8), map, cfi);
-               mask = (1 << (cfi->device_type * 8)) - 1;
+               mask = (1ULL << (cfi->device_type * 8)) - 1;
                if (ofs >= map->size)
                        return 0;
                result = map_read(map, base + ofs);
@@ -1937,7 +1937,7 @@ static inline u32 jedec_read_id(struct map_info *map, uint32_t base,
        map_word result;
        unsigned long mask;
        u32 ofs = cfi_build_cmd_addr(1, map, cfi);
-       mask = (1 << (cfi->device_type * 8)) -1;
+       mask = (1ULL << (cfi->device_type * 8)) - 1;
        result = map_read(map, base + ofs);
        return result.x[0] & mask;
 }