| Message ID | 20210914205333.3519115-1-mr.nuke.me@gmail.com |
|---|---|
| State | Accepted |
| Commit | 1ac7580a225408a46eecb9046ad5f38d7ea4a520 |
| Headers | show |
| Series | image: Avoid erroneous double byte-swap in CRC value | expand |
On Tue, Sep 14, 2021 at 03:53:33PM -0500, Alexandru Gagniuc wrote: > The hash algorithm selection was streamlined in commit 92055e138f28 > ("image: Drop if/elseif hash selection in calculate_hash()"). Said > commit kept the call to cpu_to_uimage() to convert the CRC to big > endian format. > > This would have been correct when calling crc32_wd(). However, the > ->hash_func_ws member of crc32 points to crc32_wd_buf(), which already > converts the CRC to big endian. On a little endian host, doing both > conversions results in a little-endian CRC. This is incorrect. > > To remedy this, simply drop the call to cpu_to_uimage(), thus only > doing the byte-order conversion once. > > Fixes: 92055e138f28 ("image: Drop if/elseif hash selection in > calculate_hash()") > Tested-by: Tom Rini <trini@konsulko.com> > Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com> Applied to u-boot/master, thanks!
diff --git a/common/image-fit.c b/common/image-fit.c index 92d9141bcd..f02d437539 100644 --- a/common/image-fit.c +++ b/common/image-fit.c @@ -1193,12 +1193,6 @@ int fit_set_timestamp(void *fit, int noffset, time_t timestamp) return 0; } -static void crc32_uimage_fixup(void *value) -{ - /* TODO: In C, this type punning is undefined behavior: */ - *((uint32_t *)value) = cpu_to_uimage(*((uint32_t *)value)); -} - /** * calculate_hash - calculate and return hash for provided input data * @data: pointer to the input data @@ -1232,9 +1226,6 @@ int calculate_hash(const void *data, int data_len, const char *name, algo->hash_func_ws(data, data_len, value, algo->chunk_size); *value_len = algo->digest_size; - if (!strcmp(name, "crc32")) - crc32_uimage_fixup(value); - return 0; }
The hash algorithm selection was streamlined in commit 92055e138f28 ("image: Drop if/elseif hash selection in calculate_hash()"). Said commit kept the call to cpu_to_uimage() to convert the CRC to big endian format. This would have been correct when calling crc32_wd(). However, the ->hash_func_ws member of crc32 points to crc32_wd_buf(), which already converts the CRC to big endian. On a little endian host, doing both conversions results in a little-endian CRC. This is incorrect. To remedy this, simply drop the call to cpu_to_uimage(), thus only doing the byte-order conversion once. Fixes: 92055e138f28 ("image: Drop if/elseif hash selection in calculate_hash()") Tested-by: Tom Rini <trini@konsulko.com> Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com> --- common/image-fit.c | 9 --------- 1 file changed, 9 deletions(-)