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: kernel test robot <lkp@intel.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 2c226e634ae9790f6c866dbc88d69545ad6ec90a..977208aecd06679d001ab94a105b7cf71f340376 100644 (file)
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -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;
                        }

diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index f6a7e9643b546b1fecad77ef87684fedb5c45526..a7206cc1d7d19129e6511a93f7452e1a9fa4287d 100644 (file)
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -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,

diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index ea8ff8a07b36b4b80cbb664126614643e628d1e7..3d8e9d5db5aa5125b1136974f47f3a9062d3ddb9 100644 (file)
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -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));
        }
 

diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 3f8d53a03612006b48a391a8ed3df004fda7f3d6..8e2a121af5e115ff44271bc643a84756a2df4fa1 100644 (file)
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -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);