mirror of
https://github.com/openwrt/openwrt.git
synced 2025-01-05 21:44:21 +00:00
75 lines
2.6 KiB
Diff
75 lines
2.6 KiB
Diff
|
From 4e242d6e08ad1d85b832e158cd0eafcb8f3f76a1 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Linus Walleij <linus.walleij@linaro.org>
|
||
|
|
Date: Tue, 30 May 2023 22:40:31 +0200
|
||
|
|
Subject: [PATCH v3] 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: Nicolas Pitre <npitre@baylibre.com>
|
||
|
|
Cc: stable@vger.kernel.org
|
||
|
|
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
|
||
|
|
---
|
||
|
|
ChangeLog v2->v3:
|
||
|
|
- Move the byte swapping to a small loop in read_pri_intelext()
|
||
|
|
so all bytes are swapped as we reach cfi_intelext_otp_walk().
|
||
|
|
ChangeLog v1->v2:
|
||
|
|
- Drill deeper and discover a big endian compatibility issue.
|
||
|
|
---
|
||
|
|
drivers/mtd/chips/cfi_cmdset_0001.c | 20 ++++++++++++++++++--
|
||
|
|
1 file changed, 18 insertions(+), 2 deletions(-)
|
||
|
|
|
||
|
|
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
|
||
|
|
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
|
||
|
|
@@ -421,9 +421,25 @@ read_pri_intelext(struct map_info *map,
|
||
|
|
extra_size = 0;
|
||
|
|
|
||
|
|
/* Protection Register info */
|
||
|
|
- if (extp->NumProtectionFields)
|
||
|
|
+ if (extp->NumProtectionFields) {
|
||
|
|
+ struct cfi_intelext_otpinfo *otp =
|
||
|
|
+ (struct cfi_intelext_otpinfo *)&extp->extra[0];
|
||
|
|
+
|
||
|
|
extra_size += (extp->NumProtectionFields - 1) *
|
||
|
|
- sizeof(struct cfi_intelext_otpinfo);
|
||
|
|
+ sizeof(struct cfi_intelext_otpinfo);
|
||
|
|
+
|
||
|
|
+ if (extp_size >= sizeof(*extp) + extra_size) {
|
||
|
|
+ int i;
|
||
|
|
+
|
||
|
|
+ /* Do some byteswapping if necessary */
|
||
|
|
+ for (i = 0; i < extp->NumProtectionFields - 1; i++) {
|
||
|
|
+ otp->ProtRegAddr = le32_to_cpu(otp->ProtRegAddr);
|
||
|
|
+ otp->FactGroups = le16_to_cpu(otp->FactGroups);
|
||
|
|
+ otp->UserGroups = le16_to_cpu(otp->UserGroups);
|
||
|
|
+ otp++;
|
||
|
|
+ }
|
||
|
|
+ }
|
||
|
|
+ }
|
||
|
|
}
|
||
|
|
|
||
|
|
if (extp->MinorVersion >= '1') {
|