linux/drivers/mtd
Linus Walleij 565fe15062 mtd: cfi_cmdset_0001: Byte swap OTP info
Currently the offset into the device when looking for OTP
bits can go outside of the address of the MTD NOR devices,
and if that memory isn't readable, bad things happen
on the IXP4xx (added prints that illustrate the problem before
the crash):

cfi_intelext_otp_walk walk OTP on chip 0 start at reg_prot_offset 0x00000100
ixp4xx_copy_from copy from 0x00000100 to 0xc880dd78
cfi_intelext_otp_walk walk OTP on chip 0 start at reg_prot_offset 0x12000000
ixp4xx_copy_from copy from 0x12000000 to 0xc880dd78
8<--- cut here ---
Unable to handle kernel paging request at virtual address db000000
[db000000] *pgd=00000000
(...)

This happens in this case because the IXP4xx is big endian and
the 32- and 16-bit fields in the struct cfi_intelext_otpinfo are not
properly byteswapped. Compare to how the code in read_pri_intelext()
byteswaps the fields in struct cfi_pri_intelext.

Adding a small byte swapping loop for the OTP in read_pri_intelext()
and the crash goes away.

The problem went unnoticed for many years until I enabled
CONFIG_MTD_OTP on the IXP4xx as well, triggering the bug.

Cc: stable@vger.kernel.org
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20231020-mtd-otp-byteswap-v4-1-0d132c06aa9d@linaro.org
2023-10-27 19:45:11 +02:00
..
chips mtd: cfi_cmdset_0001: Byte swap OTP info 2023-10-27 19:45:11 +02:00
devices mtd: st_spi_fsm: Convert to platform remove callback returning void 2023-10-16 10:56:47 +02:00
hyperbus mtd: hyperbus: rpc-if: Convert to platform remove callback returning void 2023-10-16 10:56:48 +02:00
lpddr mtd: lpddr2_nvm: Convert to platform remove callback returning void 2023-10-16 10:56:48 +02:00
maps mtd: Use device_get_match_data() 2023-10-16 11:13:27 +02:00
nand mtd: Use device_get_match_data() 2023-10-16 11:13:27 +02:00
parsers Raw NAND core changes: 2023-04-19 20:39:03 +02:00
spi-nor mtd: spi-nor: nxp-spifi: Convert to platform remove callback returning void 2023-10-16 10:56:48 +02:00
tests treewide: use get_random_u32_below() instead of deprecated function 2022-11-18 02:15:15 +01:00
ubi block: replace fmode_t with a block-specific type for block open flags 2023-06-12 08:04:05 -06:00
ftl.c mtd: ftl: use container_of() rather than cast 2022-09-19 18:14:53 +02:00
inftlcore.c mtd: inftlcore: fix repeated words in comments 2022-11-07 17:14:21 +01:00
inftlmount.c mtd: inftl: remove unnecessary oom message 2021-06-11 20:44:21 +02:00
Kconfig mtdblock: Add comment about UBI block devices 2021-08-06 22:05:13 +02:00
Makefile
mtd_blkdevs.c block: replace fmode_t with a block-specific type for block open flags 2023-06-12 08:04:05 -06:00
mtdblock_ro.c mtdblock: make warning messages ratelimited 2023-07-27 17:16:14 +02:00
mtdblock.c mtdblock: make warning messages ratelimited 2023-07-27 17:16:14 +02:00
mtdchar.c mtdchar: mark bits of ioctl handler noinline 2023-06-01 18:12:31 +02:00
mtdconcat.c mtd: fix repeated word in comment 2022-09-20 10:40:30 +02:00
mtdcore.c mtd: Add WARN_ON_ONCE() to mtd_read() to check the return value 2023-10-16 10:50:28 +02:00
mtdcore.h mtd: use refcount to prevent corruption 2023-07-12 13:30:08 +02:00
mtdoops.c mtd: mtdoops: panic caused mtdoops to call mtdoops_erase function immediately 2022-11-07 17:08:00 +01:00
mtdpart.c mtd: mtdpart: check for subpartitions parsing result 2023-10-16 10:50:32 +02:00
mtdpstore.c mtd: Fix a typo in a comment 2022-09-19 18:14:53 +02:00
mtdsuper.c mtd: key superblock by device number 2023-08-31 12:47:15 +02:00
mtdswap.c mtd: always initialize 'stats' in struct mtd_oob_ops 2022-09-21 10:38:07 +02:00
nftlcore.c mtd: always initialize 'stats' in struct mtd_oob_ops 2022-09-21 10:38:07 +02:00
nftlmount.c
rfd_ftl.c mtd/rfd_ftl: don't cast away the type when calling add_mtd_blktrans_dev 2021-08-23 10:01:06 +02:00
sm_ftl.c mtd: sm_ftl: Fix typos in comments 2023-06-22 23:00:43 +02:00
sm_ftl.h
ssfdc.c mtd: always initialize 'stats' in struct mtd_oob_ops 2022-09-21 10:38:07 +02:00