bybrooklyn/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-04-18 06:44:00 -04:00
Code Issues Packages Projects Releases Wiki Activity

ima/evm: Fix type mismatch

Browse Source 
The endianness of a variable written to the measurement list cannot be
determined at compile time, as it depends on the value of the
ima_canonical_fmt global variable (set through a kernel option with the
same name if the machine is big endian).

If ima_canonical_fmt is false, the endianness of a variable is the same as
the machine; if ima_canonical_fmt is true, the endianness is little endian.
The warning arises due to this type of instruction:

var = cpu_to_leXX(var)

which tries to assign a value in little endian to a variable with native
endianness (little or big endian).

Given that the variables set with this instruction are not used in any
operation but just written to a buffer, it is safe to force the type of the
value being set to be the same of the type of the variable with:

var = (__force <var type>)cpu_to_leXX(var)

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This commit is contained in:
Roberto Sassu
2021-06-08 14:31:22 +02:00
committed by Mimi Zohar
parent 24c9ae23bd
commit 6b26285f44
4 changed files with 12 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
security/integrity/ima/ima_fs.c
View File

@@ -147,7 +147,7 @@ int ima_measurements_show(struct seq_file *m, void *v)
* PCR used defaults to the same (config option) in
* little-endian format, unless set in policy
*/
pcr = !ima_canonical_fmt ? e->pcr : cpu_to_le32(e->pcr);
pcr = !ima_canonical_fmt ? e->pcr : (__force u32)cpu_to_le32(e->pcr);
ima_putc(m, &pcr, sizeof(e->pcr));
/* 2nd: template digest */
@@ -155,7 +155,7 @@ int ima_measurements_show(struct seq_file *m, void *v)
/* 3rd: template name size */
namelen = !ima_canonical_fmt ? strlen(template_name) :
cpu_to_le32(strlen(template_name));
(__force u32)cpu_to_le32(strlen(template_name));
ima_putc(m, &namelen, sizeof(namelen));
/* 4th: template name */
@@ -167,7 +167,7 @@ int ima_measurements_show(struct seq_file *m, void *v)
if (!is_ima_template) {
template_data_len = !ima_canonical_fmt ? e->template_data_len :
cpu_to_le32(e->template_data_len);
(__force u32)cpu_to_le32(e->template_data_len);
ima_putc(m, &template_data_len, sizeof(e->template_data_len));
}