| Message ID | 20210701125552.2958008-3-roberto.sassu@huawei.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | ima: Provide more info about buffer measurement | expand |
On 7/1/2021 5:55 AM, Roberto Sassu wrote: > ima_measure_critical_data() and process_buffer_measurement() currently > don't return a result. A caller wouldn't be able to know whether those > functions were executed successfully. > > This patch modifies the return type from void to int, and returns 0 if the > buffer has been successfully measured, a negative value otherwise. > > Also, this patch does not modify the behavior of existing callers by > processing the returned value. Instead, the value is stored in a variable > marked as __maybe_unused. > > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> > --- > include/linux/ima.h | 15 +++--- > security/integrity/ima/ima.h | 10 ++-- > security/integrity/ima/ima_appraise.c | 4 +- > security/integrity/ima/ima_asymmetric_keys.c | 4 +- > security/integrity/ima/ima_init.c | 6 ++- > security/integrity/ima/ima_main.c | 48 ++++++++++++-------- > security/integrity/ima/ima_queue_keys.c | 15 +++--- > security/selinux/ima.c | 10 ++-- > 8 files changed, 66 insertions(+), 46 deletions(-) > > diff --git a/include/linux/ima.h b/include/linux/ima.h > index 81e830d01ced..60492263aa64 100644 > --- a/include/linux/ima.h > +++ b/include/linux/ima.h > @@ -35,10 +35,10 @@ extern void ima_post_path_mknod(struct user_namespace *mnt_userns, > extern int ima_file_hash(struct file *file, char *buf, size_t buf_size); > extern int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size); > extern void ima_kexec_cmdline(int kernel_fd, const void *buf, int size); > -extern void ima_measure_critical_data(const char *event_label, > - const char *event_name, > - const void *buf, size_t buf_len, > - bool hash); > +extern int ima_measure_critical_data(const char *event_label, > + const char *event_name, > + const void *buf, size_t buf_len, > + bool hash); > > #ifdef CONFIG_IMA_APPRAISE_BOOTPARAM > extern void ima_appraise_parse_cmdline(void); > @@ -144,10 +144,13 @@ static inline int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size > > static inline void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) {} > > -static inline void ima_measure_critical_data(const char *event_label, > +static inline int ima_measure_critical_data(const char *event_label, > const char *event_name, > const void *buf, size_t buf_len, > - bool hash) {} > + bool hash) > +{ > + return -ENOENT; > +} > > #endif /* CONFIG_IMA */ > > diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h > index f0e448ed1f9f..03db221324c3 100644 > --- a/security/integrity/ima/ima.h > +++ b/security/integrity/ima/ima.h > @@ -264,11 +264,11 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, > struct evm_ima_xattr_data *xattr_value, > int xattr_len, const struct modsig *modsig, int pcr, > struct ima_template_desc *template_desc); > -void process_buffer_measurement(struct user_namespace *mnt_userns, > - struct inode *inode, const void *buf, int size, > - const char *eventname, enum ima_hooks func, > - int pcr, const char *func_data, > - bool buf_hash); > +int process_buffer_measurement(struct user_namespace *mnt_userns, > + struct inode *inode, const void *buf, int size, > + const char *eventname, enum ima_hooks func, > + int pcr, const char *func_data, > + bool buf_hash); > void ima_audit_measurement(struct integrity_iint_cache *iint, > const unsigned char *filename); > int ima_alloc_init_template(struct ima_event_data *event_data, > diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c > index ef9dcfce45d4..275a2377743f 100644 > --- a/security/integrity/ima/ima_appraise.c > +++ b/security/integrity/ima/ima_appraise.c > @@ -345,6 +345,7 @@ int ima_check_blacklist(struct integrity_iint_cache *iint, > enum hash_algo hash_algo; > const u8 *digest = NULL; > u32 digestsize = 0; > + int process_rc __maybe_unused; > int rc = 0; > > if (!(iint->flags & IMA_CHECK_BLACKLIST)) > @@ -355,7 +356,8 @@ int ima_check_blacklist(struct integrity_iint_cache *iint, > > rc = is_binary_blacklisted(digest, digestsize); > if ((rc == -EPERM) && (iint->flags & IMA_MEASURE)) > - process_buffer_measurement(&init_user_ns, NULL, digest, digestsize, > + process_rc = process_buffer_measurement(&init_user_ns, I think there is no need to make this change now. If and when ima_check_blacklist() needs to look at the return value of p_b_m(), this change can be made. > + NULL, digest, digestsize, > "blacklisted-hash", NONE, > pcr, NULL, false); > } > diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c > index c985418698a4..910367cdd920 100644 > --- a/security/integrity/ima/ima_asymmetric_keys.c > +++ b/security/integrity/ima/ima_asymmetric_keys.c > @@ -31,6 +31,7 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key, > unsigned long flags, bool create) > { > bool queued = false; > + int ret __maybe_unused; > > /* Only asymmetric keys are handled by this hook. */ > if (key->type != &key_type_asymmetric) > @@ -60,7 +61,8 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key, > * if the IMA policy is configured to measure a key linked > * to the given keyring. > */ > - process_buffer_measurement(&init_user_ns, NULL, payload, payload_len, > + ret = process_buffer_measurement(&init_user_ns, NULL, > + payload, payload_len, Same comment as in ima_check_blacklist() - this change be made when needed. > keyring->description, KEY_CHECK, 0, > keyring->description, false); > } > diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c > index 5076a7d9d23e..6790eea88db8 100644 > --- a/security/integrity/ima/ima_init.c > +++ b/security/integrity/ima/ima_init.c > @@ -118,6 +118,7 @@ void __init ima_load_x509(void) > > int __init ima_init(void) > { > + int measure_rc __maybe_unused; > int rc; > > ima_tpm_chip = tpm_default_chip(); > @@ -153,8 +154,9 @@ int __init ima_init(void) > > ima_init_key_queue(); > > - ima_measure_critical_data("kernel_info", "kernel_version", > - UTS_RELEASE, strlen(UTS_RELEASE), false); > + measure_rc = ima_measure_critical_data("kernel_info", "kernel_version", > + UTS_RELEASE, strlen(UTS_RELEASE), > + false); Same comment as in ima_check_blacklist() - this change be made when needed. > > return rc; > } > diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c > index 8ef1fa357e0c..3386e7436440 100644 > --- a/security/integrity/ima/ima_main.c > +++ b/security/integrity/ima/ima_main.c > @@ -827,7 +827,7 @@ int ima_post_load_data(char *buf, loff_t size, > return 0; > } > > -/* > +/** > * process_buffer_measurement - Measure the buffer or the buffer data hash > * @mnt_userns: user namespace of the mount the inode was found from > * @inode: inode associated with the object being measured (NULL for KEY_CHECK) > @@ -840,12 +840,15 @@ int ima_post_load_data(char *buf, loff_t size, > * @buf_hash: measure buffer data hash > * > * Based on policy, either the buffer data or buffer data hash is measured > + * > + * Return: 0 if the buffer has been successfully measured, a negative value > + * otherwise. > */ > -void process_buffer_measurement(struct user_namespace *mnt_userns, > - struct inode *inode, const void *buf, int size, > - const char *eventname, enum ima_hooks func, > - int pcr, const char *func_data, > - bool buf_hash) > +int process_buffer_measurement(struct user_namespace *mnt_userns, > + struct inode *inode, const void *buf, int size, > + const char *eventname, enum ima_hooks func, > + int pcr, const char *func_data, > + bool buf_hash) > { > int ret = 0; > const char *audit_cause = "ENOMEM"; > @@ -867,7 +870,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, > u32 secid; > > if (!ima_policy_flag) > - return; > + return -ENOENT; > > template = ima_template_desc_buf(); > if (!template) { > @@ -889,7 +892,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, > secid, 0, func, &pcr, &template, > func_data); > if (!(action & IMA_MEASURE)) > - return; > + return -ENOENT; > } > > if (!pcr) > @@ -937,7 +940,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, > func_measure_str(func), > audit_cause, ret, 0, ret); > > - return; > + return ret; > } > > /** > @@ -951,6 +954,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, > void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) > { > struct fd f; > + int ret __maybe_unused; > > if (!buf || !size) > return; > @@ -959,9 +963,10 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) > if (!f.file) > return; > > - process_buffer_measurement(file_mnt_user_ns(f.file), file_inode(f.file), > - buf, size, "kexec-cmdline", KEXEC_CMDLINE, 0, > - NULL, false); > + ret = process_buffer_measurement(file_mnt_user_ns(f.file), > + file_inode(f.file), buf, size, > + "kexec-cmdline", KEXEC_CMDLINE, 0, > + NULL, false); Since the return value of p_b_m() is not used here, this change can be made when needed. > fdput(f); > } > > @@ -977,18 +982,21 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) > * and extend the pcr. Examples of critical data could be various data > * structures, policies, and states stored in kernel memory that can > * impact the integrity of the system. > + * > + * Return: 0 if the buffer has been successfully measured, a negative value > + * otherwise. > */ > -void ima_measure_critical_data(const char *event_label, > - const char *event_name, > - const void *buf, size_t buf_len, > - bool hash) > +int ima_measure_critical_data(const char *event_label, > + const char *event_name, > + const void *buf, size_t buf_len, > + bool hash) > { > if (!event_name || !event_label || !buf || !buf_len) > - return; > + return -ENOPARAM; > > - process_buffer_measurement(&init_user_ns, NULL, buf, buf_len, event_name, > - CRITICAL_DATA, 0, event_label, > - hash); > + return process_buffer_measurement(&init_user_ns, NULL, buf, buf_len, > + event_name, CRITICAL_DATA, 0, > + event_label, hash); > } > > static int __init init_ima(void) > diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c > index 979ef6c71f3d..e3047ce64f39 100644 > --- a/security/integrity/ima/ima_queue_keys.c > +++ b/security/integrity/ima/ima_queue_keys.c > @@ -134,6 +134,7 @@ void ima_process_queued_keys(void) > { > struct ima_key_entry *entry, *tmp; > bool process = false; > + int ret __maybe_unused; > > if (ima_process_keys) > return; > @@ -159,13 +160,13 @@ void ima_process_queued_keys(void) > > list_for_each_entry_safe(entry, tmp, &ima_keys, list) { > if (!timer_expired) > - process_buffer_measurement(&init_user_ns, NULL, > - entry->payload, > - entry->payload_len, > - entry->keyring_name, > - KEY_CHECK, 0, > - entry->keyring_name, > - false); > + ret = process_buffer_measurement(&init_user_ns, NULL, > + entry->payload, > + entry->payload_len, > + entry->keyring_name, > + KEY_CHECK, 0, > + entry->keyring_name, > + false); Same comment as above. > list_del(&entry->list); > ima_free_key_entry(entry); > } > diff --git a/security/selinux/ima.c b/security/selinux/ima.c > index 34d421861bfc..4db9fa211638 100644 > --- a/security/selinux/ima.c > +++ b/security/selinux/ima.c > @@ -75,6 +75,7 @@ void selinux_ima_measure_state_locked(struct selinux_state *state) > char *state_str = NULL; > void *policy = NULL; > size_t policy_len; > + int measure_rc __maybe_unused; > int rc = 0; > > WARN_ON(!mutex_is_locked(&state->policy_mutex)); > @@ -85,8 +86,9 @@ void selinux_ima_measure_state_locked(struct selinux_state *state) > return; > } > > - ima_measure_critical_data("selinux", "selinux-state", > - state_str, strlen(state_str), false); > + measure_rc = ima_measure_critical_data("selinux", "selinux-state", > + state_str, strlen(state_str), > + false); Since the return value of ima_measure_critical_data() is not used here, this change can be made when needed. > > kfree(state_str); > > @@ -102,8 +104,8 @@ void selinux_ima_measure_state_locked(struct selinux_state *state) > return; > } > > - ima_measure_critical_data("selinux", "selinux-policy-hash", > - policy, policy_len, true); > + measure_rc = ima_measure_critical_data("selinux", "selinux-policy-hash", > + policy, policy_len, true); Same comment as above. -lakshmi > > vfree(policy); > } >
> From: Lakshmi Ramasubramanian [mailto:nramas@linux.microsoft.com] > Sent: Thursday, July 1, 2021 6:16 PM > On 7/1/2021 5:55 AM, Roberto Sassu wrote: > > ima_measure_critical_data() and process_buffer_measurement() currently > > don't return a result. A caller wouldn't be able to know whether those > > functions were executed successfully. > > > > This patch modifies the return type from void to int, and returns 0 if the > > buffer has been successfully measured, a negative value otherwise. > > > > Also, this patch does not modify the behavior of existing callers by > > processing the returned value. Instead, the value is stored in a variable > > marked as __maybe_unused. > > > > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> > > --- > > include/linux/ima.h | 15 +++--- > > security/integrity/ima/ima.h | 10 ++-- > > security/integrity/ima/ima_appraise.c | 4 +- > > security/integrity/ima/ima_asymmetric_keys.c | 4 +- > > security/integrity/ima/ima_init.c | 6 ++- > > security/integrity/ima/ima_main.c | 48 ++++++++++++-------- > > security/integrity/ima/ima_queue_keys.c | 15 +++--- > > security/selinux/ima.c | 10 ++-- > > 8 files changed, 66 insertions(+), 46 deletions(-) > > > > diff --git a/include/linux/ima.h b/include/linux/ima.h > > index 81e830d01ced..60492263aa64 100644 > > --- a/include/linux/ima.h > > +++ b/include/linux/ima.h > > @@ -35,10 +35,10 @@ extern void ima_post_path_mknod(struct > user_namespace *mnt_userns, > > extern int ima_file_hash(struct file *file, char *buf, size_t buf_size); > > extern int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size); > > extern void ima_kexec_cmdline(int kernel_fd, const void *buf, int size); > > -extern void ima_measure_critical_data(const char *event_label, > > - const char *event_name, > > - const void *buf, size_t buf_len, > > - bool hash); > > +extern int ima_measure_critical_data(const char *event_label, > > + const char *event_name, > > + const void *buf, size_t buf_len, > > + bool hash); > > > > #ifdef CONFIG_IMA_APPRAISE_BOOTPARAM > > extern void ima_appraise_parse_cmdline(void); > > @@ -144,10 +144,13 @@ static inline int ima_inode_hash(struct inode > *inode, char *buf, size_t buf_size > > > > static inline void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) > {} > > > > -static inline void ima_measure_critical_data(const char *event_label, > > +static inline int ima_measure_critical_data(const char *event_label, > > const char *event_name, > > const void *buf, size_t buf_len, > > - bool hash) {} > > + bool hash) > > +{ > > + return -ENOENT; > > +} > > > > #endif /* CONFIG_IMA */ > > > > diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h > > index f0e448ed1f9f..03db221324c3 100644 > > --- a/security/integrity/ima/ima.h > > +++ b/security/integrity/ima/ima.h > > @@ -264,11 +264,11 @@ void ima_store_measurement(struct > integrity_iint_cache *iint, struct file *file, > > struct evm_ima_xattr_data *xattr_value, > > int xattr_len, const struct modsig *modsig, int pcr, > > struct ima_template_desc *template_desc); > > -void process_buffer_measurement(struct user_namespace *mnt_userns, > > - struct inode *inode, const void *buf, int size, > > - const char *eventname, enum ima_hooks > func, > > - int pcr, const char *func_data, > > - bool buf_hash); > > +int process_buffer_measurement(struct user_namespace *mnt_userns, > > + struct inode *inode, const void *buf, int size, > > + const char *eventname, enum ima_hooks func, > > + int pcr, const char *func_data, > > + bool buf_hash); > > void ima_audit_measurement(struct integrity_iint_cache *iint, > > const unsigned char *filename); > > int ima_alloc_init_template(struct ima_event_data *event_data, > > diff --git a/security/integrity/ima/ima_appraise.c > b/security/integrity/ima/ima_appraise.c > > index ef9dcfce45d4..275a2377743f 100644 > > --- a/security/integrity/ima/ima_appraise.c > > +++ b/security/integrity/ima/ima_appraise.c > > @@ -345,6 +345,7 @@ int ima_check_blacklist(struct integrity_iint_cache > *iint, > > enum hash_algo hash_algo; > > const u8 *digest = NULL; > > u32 digestsize = 0; > > + int process_rc __maybe_unused; > > int rc = 0; > > > > if (!(iint->flags & IMA_CHECK_BLACKLIST)) > > @@ -355,7 +356,8 @@ int ima_check_blacklist(struct integrity_iint_cache > *iint, > > > > rc = is_binary_blacklisted(digest, digestsize); > > if ((rc == -EPERM) && (iint->flags & IMA_MEASURE)) > > - process_buffer_measurement(&init_user_ns, NULL, > digest, digestsize, > > + process_rc = > process_buffer_measurement(&init_user_ns, > I think there is no need to make this change now. If and when > ima_check_blacklist() needs to look at the return value of p_b_m(), this > change can be made. Hi Lakshmi ok. I was worried about possible warnings. If it is not an issue, I will remove the assignment. Thanks Roberto HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063 Managing Director: Li Peng, Li Jian, Shi Yanli > > + NULL, digest, digestsize, > > "blacklisted-hash", NONE, > > pcr, NULL, false); > > } > > diff --git a/security/integrity/ima/ima_asymmetric_keys.c > b/security/integrity/ima/ima_asymmetric_keys.c > > index c985418698a4..910367cdd920 100644 > > --- a/security/integrity/ima/ima_asymmetric_keys.c > > +++ b/security/integrity/ima/ima_asymmetric_keys.c > > @@ -31,6 +31,7 @@ void ima_post_key_create_or_update(struct key > *keyring, struct key *key, > > unsigned long flags, bool create) > > { > > bool queued = false; > > + int ret __maybe_unused; > > > > /* Only asymmetric keys are handled by this hook. */ > > if (key->type != &key_type_asymmetric) > > @@ -60,7 +61,8 @@ void ima_post_key_create_or_update(struct key > *keyring, struct key *key, > > * if the IMA policy is configured to measure a key linked > > * to the given keyring. > > */ > > - process_buffer_measurement(&init_user_ns, NULL, payload, > payload_len, > > + ret = process_buffer_measurement(&init_user_ns, NULL, > > + payload, payload_len, > Same comment as in ima_check_blacklist() - this change be made when > needed. > > > keyring->description, KEY_CHECK, 0, > > keyring->description, false); > > } > > diff --git a/security/integrity/ima/ima_init.c > b/security/integrity/ima/ima_init.c > > index 5076a7d9d23e..6790eea88db8 100644 > > --- a/security/integrity/ima/ima_init.c > > +++ b/security/integrity/ima/ima_init.c > > @@ -118,6 +118,7 @@ void __init ima_load_x509(void) > > > > int __init ima_init(void) > > { > > + int measure_rc __maybe_unused; > > int rc; > > > > ima_tpm_chip = tpm_default_chip(); > > @@ -153,8 +154,9 @@ int __init ima_init(void) > > > > ima_init_key_queue(); > > > > - ima_measure_critical_data("kernel_info", "kernel_version", > > - UTS_RELEASE, strlen(UTS_RELEASE), false); > > + measure_rc = ima_measure_critical_data("kernel_info", > "kernel_version", > > + UTS_RELEASE, > strlen(UTS_RELEASE), > > + false); > Same comment as in ima_check_blacklist() - this change be made when > needed. > > > > > return rc; > > } > > diff --git a/security/integrity/ima/ima_main.c > b/security/integrity/ima/ima_main.c > > index 8ef1fa357e0c..3386e7436440 100644 > > --- a/security/integrity/ima/ima_main.c > > +++ b/security/integrity/ima/ima_main.c > > @@ -827,7 +827,7 @@ int ima_post_load_data(char *buf, loff_t size, > > return 0; > > } > > > > -/* > > +/** > > * process_buffer_measurement - Measure the buffer or the buffer data > hash > > * @mnt_userns: user namespace of the mount the inode was found > from > > * @inode: inode associated with the object being measured (NULL for > KEY_CHECK) > > @@ -840,12 +840,15 @@ int ima_post_load_data(char *buf, loff_t size, > > * @buf_hash: measure buffer data hash > > * > > * Based on policy, either the buffer data or buffer data hash is measured > > + * > > + * Return: 0 if the buffer has been successfully measured, a negative value > > + * otherwise. > > */ > > -void process_buffer_measurement(struct user_namespace *mnt_userns, > > - struct inode *inode, const void *buf, int size, > > - const char *eventname, enum ima_hooks > func, > > - int pcr, const char *func_data, > > - bool buf_hash) > > +int process_buffer_measurement(struct user_namespace *mnt_userns, > > + struct inode *inode, const void *buf, int size, > > + const char *eventname, enum ima_hooks func, > > + int pcr, const char *func_data, > > + bool buf_hash) > > { > > int ret = 0; > > const char *audit_cause = "ENOMEM"; > > @@ -867,7 +870,7 @@ void process_buffer_measurement(struct > user_namespace *mnt_userns, > > u32 secid; > > > > if (!ima_policy_flag) > > - return; > > + return -ENOENT; > > > > template = ima_template_desc_buf(); > > if (!template) { > > @@ -889,7 +892,7 @@ void process_buffer_measurement(struct > user_namespace *mnt_userns, > > secid, 0, func, &pcr, &template, > > func_data); > > if (!(action & IMA_MEASURE)) > > - return; > > + return -ENOENT; > > } > > > > if (!pcr) > > @@ -937,7 +940,7 @@ void process_buffer_measurement(struct > user_namespace *mnt_userns, > > func_measure_str(func), > > audit_cause, ret, 0, ret); > > > > - return; > > + return ret; > > } > > > > /** > > @@ -951,6 +954,7 @@ void process_buffer_measurement(struct > user_namespace *mnt_userns, > > void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) > > { > > struct fd f; > > + int ret __maybe_unused; > > > > if (!buf || !size) > > return; > > @@ -959,9 +963,10 @@ void ima_kexec_cmdline(int kernel_fd, const void > *buf, int size) > > if (!f.file) > > return; > > > > - process_buffer_measurement(file_mnt_user_ns(f.file), > file_inode(f.file), > > - buf, size, "kexec-cmdline", KEXEC_CMDLINE, > 0, > > - NULL, false); > > + ret = process_buffer_measurement(file_mnt_user_ns(f.file), > > + file_inode(f.file), buf, size, > > + "kexec-cmdline", KEXEC_CMDLINE, 0, > > + NULL, false); > Since the return value of p_b_m() is not used here, this change can be > made when needed. > > > fdput(f); > > } > > > > @@ -977,18 +982,21 @@ void ima_kexec_cmdline(int kernel_fd, const void > *buf, int size) > > * and extend the pcr. Examples of critical data could be various data > > * structures, policies, and states stored in kernel memory that can > > * impact the integrity of the system. > > + * > > + * Return: 0 if the buffer has been successfully measured, a negative value > > + * otherwise. > > */ > > -void ima_measure_critical_data(const char *event_label, > > - const char *event_name, > > - const void *buf, size_t buf_len, > > - bool hash) > > +int ima_measure_critical_data(const char *event_label, > > + const char *event_name, > > + const void *buf, size_t buf_len, > > + bool hash) > > { > > if (!event_name || !event_label || !buf || !buf_len) > > - return; > > + return -ENOPARAM; > > > > - process_buffer_measurement(&init_user_ns, NULL, buf, buf_len, > event_name, > > - CRITICAL_DATA, 0, event_label, > > - hash); > > + return process_buffer_measurement(&init_user_ns, NULL, buf, > buf_len, > > + event_name, CRITICAL_DATA, 0, > > + event_label, hash); > > } > > > > static int __init init_ima(void) > > diff --git a/security/integrity/ima/ima_queue_keys.c > b/security/integrity/ima/ima_queue_keys.c > > index 979ef6c71f3d..e3047ce64f39 100644 > > --- a/security/integrity/ima/ima_queue_keys.c > > +++ b/security/integrity/ima/ima_queue_keys.c > > @@ -134,6 +134,7 @@ void ima_process_queued_keys(void) > > { > > struct ima_key_entry *entry, *tmp; > > bool process = false; > > + int ret __maybe_unused; > > > > if (ima_process_keys) > > return; > > @@ -159,13 +160,13 @@ void ima_process_queued_keys(void) > > > > list_for_each_entry_safe(entry, tmp, &ima_keys, list) { > > if (!timer_expired) > > - process_buffer_measurement(&init_user_ns, NULL, > > - entry->payload, > > - entry->payload_len, > > - entry->keyring_name, > > - KEY_CHECK, 0, > > - entry->keyring_name, > > - false); > > + ret = process_buffer_measurement(&init_user_ns, > NULL, > > + entry->payload, > > + entry->payload_len, > > + entry- > >keyring_name, > > + KEY_CHECK, 0, > > + entry- > >keyring_name, > > + false); > Same comment as above. > > > list_del(&entry->list); > > ima_free_key_entry(entry); > > } > > diff --git a/security/selinux/ima.c b/security/selinux/ima.c > > index 34d421861bfc..4db9fa211638 100644 > > --- a/security/selinux/ima.c > > +++ b/security/selinux/ima.c > > @@ -75,6 +75,7 @@ void selinux_ima_measure_state_locked(struct > selinux_state *state) > > char *state_str = NULL; > > void *policy = NULL; > > size_t policy_len; > > + int measure_rc __maybe_unused; > > int rc = 0; > > > > WARN_ON(!mutex_is_locked(&state->policy_mutex)); > > @@ -85,8 +86,9 @@ void selinux_ima_measure_state_locked(struct > selinux_state *state) > > return; > > } > > > > - ima_measure_critical_data("selinux", "selinux-state", > > - state_str, strlen(state_str), false); > > + measure_rc = ima_measure_critical_data("selinux", "selinux-state", > > + state_str, strlen(state_str), > > + false); > Since the return value of ima_measure_critical_data() is not used here, > this change can be made when needed. > > > > > kfree(state_str); > > > > @@ -102,8 +104,8 @@ void selinux_ima_measure_state_locked(struct > selinux_state *state) > > return; > > } > > > > - ima_measure_critical_data("selinux", "selinux-policy-hash", > > - policy, policy_len, true); > > + measure_rc = ima_measure_critical_data("selinux", "selinux-policy- > hash", > > + policy, policy_len, true); > Same comment as above. > > -lakshmi > > > > > vfree(policy); > > } > >
diff --git a/include/linux/ima.h b/include/linux/ima.h index 81e830d01ced..60492263aa64 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -35,10 +35,10 @@ extern void ima_post_path_mknod(struct user_namespace *mnt_userns, extern int ima_file_hash(struct file *file, char *buf, size_t buf_size); extern int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size); extern void ima_kexec_cmdline(int kernel_fd, const void *buf, int size); -extern void ima_measure_critical_data(const char *event_label, - const char *event_name, - const void *buf, size_t buf_len, - bool hash); +extern int ima_measure_critical_data(const char *event_label, + const char *event_name, + const void *buf, size_t buf_len, + bool hash); #ifdef CONFIG_IMA_APPRAISE_BOOTPARAM extern void ima_appraise_parse_cmdline(void); @@ -144,10 +144,13 @@ static inline int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size static inline void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) {} -static inline void ima_measure_critical_data(const char *event_label, +static inline int ima_measure_critical_data(const char *event_label, const char *event_name, const void *buf, size_t buf_len, - bool hash) {} + bool hash) +{ + return -ENOENT; +} #endif /* CONFIG_IMA */ diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index f0e448ed1f9f..03db221324c3 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -264,11 +264,11 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, struct evm_ima_xattr_data *xattr_value, int xattr_len, const struct modsig *modsig, int pcr, struct ima_template_desc *template_desc); -void process_buffer_measurement(struct user_namespace *mnt_userns, - struct inode *inode, const void *buf, int size, - const char *eventname, enum ima_hooks func, - int pcr, const char *func_data, - bool buf_hash); +int process_buffer_measurement(struct user_namespace *mnt_userns, + struct inode *inode, const void *buf, int size, + const char *eventname, enum ima_hooks func, + int pcr, const char *func_data, + bool buf_hash); void ima_audit_measurement(struct integrity_iint_cache *iint, const unsigned char *filename); int ima_alloc_init_template(struct ima_event_data *event_data, diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index ef9dcfce45d4..275a2377743f 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -345,6 +345,7 @@ int ima_check_blacklist(struct integrity_iint_cache *iint, enum hash_algo hash_algo; const u8 *digest = NULL; u32 digestsize = 0; + int process_rc __maybe_unused; int rc = 0; if (!(iint->flags & IMA_CHECK_BLACKLIST)) @@ -355,7 +356,8 @@ int ima_check_blacklist(struct integrity_iint_cache *iint, rc = is_binary_blacklisted(digest, digestsize); if ((rc == -EPERM) && (iint->flags & IMA_MEASURE)) - process_buffer_measurement(&init_user_ns, NULL, digest, digestsize, + process_rc = process_buffer_measurement(&init_user_ns, + NULL, digest, digestsize, "blacklisted-hash", NONE, pcr, NULL, false); } diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c index c985418698a4..910367cdd920 100644 --- a/security/integrity/ima/ima_asymmetric_keys.c +++ b/security/integrity/ima/ima_asymmetric_keys.c @@ -31,6 +31,7 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key, unsigned long flags, bool create) { bool queued = false; + int ret __maybe_unused; /* Only asymmetric keys are handled by this hook. */ if (key->type != &key_type_asymmetric) @@ -60,7 +61,8 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key, * if the IMA policy is configured to measure a key linked * to the given keyring. */ - process_buffer_measurement(&init_user_ns, NULL, payload, payload_len, + ret = process_buffer_measurement(&init_user_ns, NULL, + payload, payload_len, keyring->description, KEY_CHECK, 0, keyring->description, false); } diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index 5076a7d9d23e..6790eea88db8 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -118,6 +118,7 @@ void __init ima_load_x509(void) int __init ima_init(void) { + int measure_rc __maybe_unused; int rc; ima_tpm_chip = tpm_default_chip(); @@ -153,8 +154,9 @@ int __init ima_init(void) ima_init_key_queue(); - ima_measure_critical_data("kernel_info", "kernel_version", - UTS_RELEASE, strlen(UTS_RELEASE), false); + measure_rc = ima_measure_critical_data("kernel_info", "kernel_version", + UTS_RELEASE, strlen(UTS_RELEASE), + false); return rc; } diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 8ef1fa357e0c..3386e7436440 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -827,7 +827,7 @@ int ima_post_load_data(char *buf, loff_t size, return 0; } -/* +/** * process_buffer_measurement - Measure the buffer or the buffer data hash * @mnt_userns: user namespace of the mount the inode was found from * @inode: inode associated with the object being measured (NULL for KEY_CHECK) @@ -840,12 +840,15 @@ int ima_post_load_data(char *buf, loff_t size, * @buf_hash: measure buffer data hash * * Based on policy, either the buffer data or buffer data hash is measured + * + * Return: 0 if the buffer has been successfully measured, a negative value + * otherwise. */ -void process_buffer_measurement(struct user_namespace *mnt_userns, - struct inode *inode, const void *buf, int size, - const char *eventname, enum ima_hooks func, - int pcr, const char *func_data, - bool buf_hash) +int process_buffer_measurement(struct user_namespace *mnt_userns, + struct inode *inode, const void *buf, int size, + const char *eventname, enum ima_hooks func, + int pcr, const char *func_data, + bool buf_hash) { int ret = 0; const char *audit_cause = "ENOMEM"; @@ -867,7 +870,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, u32 secid; if (!ima_policy_flag) - return; + return -ENOENT; template = ima_template_desc_buf(); if (!template) { @@ -889,7 +892,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, secid, 0, func, &pcr, &template, func_data); if (!(action & IMA_MEASURE)) - return; + return -ENOENT; } if (!pcr) @@ -937,7 +940,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, func_measure_str(func), audit_cause, ret, 0, ret); - return; + return ret; } /** @@ -951,6 +954,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) { struct fd f; + int ret __maybe_unused; if (!buf || !size) return; @@ -959,9 +963,10 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) if (!f.file) return; - process_buffer_measurement(file_mnt_user_ns(f.file), file_inode(f.file), - buf, size, "kexec-cmdline", KEXEC_CMDLINE, 0, - NULL, false); + ret = process_buffer_measurement(file_mnt_user_ns(f.file), + file_inode(f.file), buf, size, + "kexec-cmdline", KEXEC_CMDLINE, 0, + NULL, false); fdput(f); } @@ -977,18 +982,21 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) * and extend the pcr. Examples of critical data could be various data * structures, policies, and states stored in kernel memory that can * impact the integrity of the system. + * + * Return: 0 if the buffer has been successfully measured, a negative value + * otherwise. */ -void ima_measure_critical_data(const char *event_label, - const char *event_name, - const void *buf, size_t buf_len, - bool hash) +int ima_measure_critical_data(const char *event_label, + const char *event_name, + const void *buf, size_t buf_len, + bool hash) { if (!event_name || !event_label || !buf || !buf_len) - return; + return -ENOPARAM; - process_buffer_measurement(&init_user_ns, NULL, buf, buf_len, event_name, - CRITICAL_DATA, 0, event_label, - hash); + return process_buffer_measurement(&init_user_ns, NULL, buf, buf_len, + event_name, CRITICAL_DATA, 0, + event_label, hash); } static int __init init_ima(void) diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c index 979ef6c71f3d..e3047ce64f39 100644 --- a/security/integrity/ima/ima_queue_keys.c +++ b/security/integrity/ima/ima_queue_keys.c @@ -134,6 +134,7 @@ void ima_process_queued_keys(void) { struct ima_key_entry *entry, *tmp; bool process = false; + int ret __maybe_unused; if (ima_process_keys) return; @@ -159,13 +160,13 @@ void ima_process_queued_keys(void) list_for_each_entry_safe(entry, tmp, &ima_keys, list) { if (!timer_expired) - process_buffer_measurement(&init_user_ns, NULL, - entry->payload, - entry->payload_len, - entry->keyring_name, - KEY_CHECK, 0, - entry->keyring_name, - false); + ret = process_buffer_measurement(&init_user_ns, NULL, + entry->payload, + entry->payload_len, + entry->keyring_name, + KEY_CHECK, 0, + entry->keyring_name, + false); list_del(&entry->list); ima_free_key_entry(entry); } diff --git a/security/selinux/ima.c b/security/selinux/ima.c index 34d421861bfc..4db9fa211638 100644 --- a/security/selinux/ima.c +++ b/security/selinux/ima.c @@ -75,6 +75,7 @@ void selinux_ima_measure_state_locked(struct selinux_state *state) char *state_str = NULL; void *policy = NULL; size_t policy_len; + int measure_rc __maybe_unused; int rc = 0; WARN_ON(!mutex_is_locked(&state->policy_mutex)); @@ -85,8 +86,9 @@ void selinux_ima_measure_state_locked(struct selinux_state *state) return; } - ima_measure_critical_data("selinux", "selinux-state", - state_str, strlen(state_str), false); + measure_rc = ima_measure_critical_data("selinux", "selinux-state", + state_str, strlen(state_str), + false); kfree(state_str); @@ -102,8 +104,8 @@ void selinux_ima_measure_state_locked(struct selinux_state *state) return; } - ima_measure_critical_data("selinux", "selinux-policy-hash", - policy, policy_len, true); + measure_rc = ima_measure_critical_data("selinux", "selinux-policy-hash", + policy, policy_len, true); vfree(policy); }
ima_measure_critical_data() and process_buffer_measurement() currently don't return a result. A caller wouldn't be able to know whether those functions were executed successfully. This patch modifies the return type from void to int, and returns 0 if the buffer has been successfully measured, a negative value otherwise. Also, this patch does not modify the behavior of existing callers by processing the returned value. Instead, the value is stored in a variable marked as __maybe_unused. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> --- include/linux/ima.h | 15 +++--- security/integrity/ima/ima.h | 10 ++-- security/integrity/ima/ima_appraise.c | 4 +- security/integrity/ima/ima_asymmetric_keys.c | 4 +- security/integrity/ima/ima_init.c | 6 ++- security/integrity/ima/ima_main.c | 48 ++++++++++++-------- security/integrity/ima/ima_queue_keys.c | 15 +++--- security/selinux/ima.c | 10 ++-- 8 files changed, 66 insertions(+), 46 deletions(-)