Commit 6b26285f authored by Roberto Sassu's avatar Roberto Sassu Committed by Mimi Zohar
Browse files

ima/evm: Fix type mismatch 



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: default avatarkernel test robot <lkp@intel.com>
Signed-off-by: default avatarRoberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: default avatarMimi Zohar <zohar@linux.ibm.com>
parent 24c9ae23

security/integrity/evm/evm_main.c

+1 −1
Original line number Diff line number Diff line
@@ -360,7 +360,7 @@ int evm_read_protected_xattrs(struct dentry *dentry, u8 *buffer, 
			size = sizeof(u32);

			if (buffer) {

				if (canonical_fmt)

					rc = cpu_to_le32(rc);

					rc = (__force int)cpu_to_le32(rc);



				*(u32 *)(buffer + total_size) = rc;

			}

security/integrity/ima/ima_crypto.c

+2 −2
Original line number Diff line number Diff line
@@ -598,8 +598,8 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data, 
		u8 buffer[IMA_EVENT_NAME_LEN_MAX + 1] = { 0 };

		u8 *data_to_hash = field_data[i].data;

		u32 datalen = field_data[i].len;

		u32 datalen_to_hash =

		    !ima_canonical_fmt ? datalen : cpu_to_le32(datalen);

		u32 datalen_to_hash = !ima_canonical_fmt ?

				datalen : (__force u32)cpu_to_le32(datalen);



		if (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) {

			rc = crypto_shash_update(shash,

security/integrity/ima/ima_fs.c

+3 −3
Original line number Diff line number Diff line
@@ -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));

	}

security/integrity/ima/ima_template_lib.c

+6 −5
Original line number Diff line number Diff line
@@ -133,7 +133,8 @@ static void ima_show_template_data_binary(struct seq_file *m, 
	    strlen(field_data->data) : field_data->len;



	if (show != IMA_SHOW_BINARY_NO_FIELD_LEN) {

		u32 field_len = !ima_canonical_fmt ? len : cpu_to_le32(len);

		u32 field_len = !ima_canonical_fmt ?

				len : (__force u32)cpu_to_le32(len);



		ima_putc(m, &field_len, sizeof(field_len));

	}
@@ -570,9 +571,9 @@ static int ima_eventinodedac_init_common(struct ima_event_data *event_data, 


	if (ima_canonical_fmt) {

		if (sizeof(id) == sizeof(u16))

			id = cpu_to_le16(id);

			id = (__force u16)cpu_to_le16(id);

		else

			id = cpu_to_le32(id);

			id = (__force u32)cpu_to_le32(id);

	}



	return ima_write_template_field_data((void *)&id, sizeof(id),
@@ -607,7 +608,7 @@ int ima_eventinodemode_init(struct ima_event_data *event_data, 
			    struct ima_field_data *field_data)

{

	struct inode *inode;

	umode_t mode;

	u16 mode;



	if (!event_data->file)

		return 0;
@@ -615,7 +616,7 @@ int ima_eventinodemode_init(struct ima_event_data *event_data, 
	inode = file_inode(event_data->file);

	mode = inode->i_mode;

	if (ima_canonical_fmt)

		mode = cpu_to_le16(mode);

		mode = (__force u16)cpu_to_le16(mode);



	return ima_write_template_field_data((char *)&mode, sizeof(mode),

					     DATA_FMT_UINT, field_data);