From: Roberto Sassu roberto.sassu@huawei.com
euleros inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7QZ2M CVE: NA
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This patch renames ima_open_policy() and ima_release_policy() respectively to ima_open_data_upload() and ima_release_data_upload(). They will be used to implement file operations for interfaces allowing to load data from user space.
A new flag (IMA_POLICY_BUSY) has been defined to prevent concurrent policy upload.
Signed-off-by: Roberto Sassu roberto.sassu@huawei.com Signed-off-by: Tianxing Zhang zhangtianxing3@huawei.com Reviewed-by: Jason Yan yanaijie@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Signed-off-by: zhoushuiqing zhoushuiqing2@huawei.com --- security/integrity/ima/ima_fs.c | 89 ++++++++++++++++++++++++++++++++- 1 file changed, 87 insertions(+), 2 deletions(-)
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index 9f36731b4cc5b..9a8fb2a4185a1 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -471,9 +471,24 @@ static struct dentry *ima_policy; #endif
enum ima_fs_flags { +#ifdef CONFIG_IMA_DIGEST_LIST + IMA_POLICY_BUSY, +#endif IMA_FS_BUSY, };
+#ifdef CONFIG_IMA_DIGEST_LIST +static enum ima_fs_flags ima_get_dentry_flag(struct dentry *dentry) +{ + enum ima_fs_flags flag = IMA_FS_BUSY; + + if (dentry == ima_policy) + flag = IMA_POLICY_BUSY; + + return flag; +} +#endif + static unsigned long ima_fs_flags;
#ifdef CONFIG_IMA_READ_POLICY @@ -485,12 +500,42 @@ static const struct seq_operations ima_policy_seqops = { }; #endif
+#ifdef CONFIG_IMA_DIGEST_LIST +/* + * ima_open_data_upload: sequentialize access to the data upload interface + */ +static int ima_open_data_upload(struct inode *inode, struct file *filp) +{ + struct dentry *dentry = file_dentry(filp); + const struct seq_operations *seq_ops = NULL; + enum ima_fs_flags flag = ima_get_dentry_flag(dentry); + bool read_allowed = false; + + if (dentry == ima_policy) { +#ifdef CONFIG_IMA_READ_POLICY + read_allowed = true; + seq_ops = &ima_policy_seqops; +#endif + } +#else /* * ima_open_policy: sequentialize access to the policy file */ static int ima_open_policy(struct inode *inode, struct file *filp) { +#endif /* CONFIG_IMA_DIGEST_LIST */ if (!(filp->f_flags & O_WRONLY)) { +#ifdef CONFIG_IMA_DIGEST_LIST + if (!read_allowed) + return -EACCES; + if ((filp->f_flags & O_ACCMODE) != O_RDONLY) + return -EACCES; + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + return seq_open(filp, seq_ops); + } + if (test_and_set_bit(flag, &ima_fs_flags)) +#else #ifndef CONFIG_IMA_READ_POLICY return -EACCES; #else @@ -502,10 +547,25 @@ static int ima_open_policy(struct inode *inode, struct file *filp) #endif } if (test_and_set_bit(IMA_FS_BUSY, &ima_fs_flags)) +#endif return -EBUSY; return 0; }
+#ifdef CONFIG_IMA_DIGEST_LIST +/* + * ima_release_data_upload - start using the new measure policy rules. + * + * Initially, ima_measure points to the default policy rules, now + * point to the new policy rules, and remove the securityfs policy file, + * assuming a valid policy. + */ +static int ima_release_data_upload(struct inode *inode, struct file *file) +{ + struct dentry *dentry = file_dentry(file); + const char *cause = valid_policy ? "completed" : "failed"; + enum ima_fs_flags flag = ima_get_dentry_flag(dentry); +#else /* * ima_release_policy - start using the new measure policy rules. * @@ -516,9 +576,16 @@ static int ima_open_policy(struct inode *inode, struct file *filp) static int ima_release_policy(struct inode *inode, struct file *file) { const char *cause = valid_policy ? "completed" : "failed"; +#endif
if ((file->f_flags & O_ACCMODE) == O_RDONLY) return seq_release(inode, file); +#ifdef CONFIG_IMA_DIGEST_LIST + if (dentry != ima_policy) { + clear_bit(flag, &ima_fs_flags); + return 0; + } +#endif
if (valid_policy && ima_check_policy() < 0) { cause = "failed"; @@ -532,7 +599,11 @@ static int ima_release_policy(struct inode *inode, struct file *file) if (!valid_policy) { ima_delete_rules(); valid_policy = 1; +#ifdef CONFIG_IMA_DIGEST_LIST + clear_bit(flag, &ima_fs_flags); +#else clear_bit(IMA_FS_BUSY, &ima_fs_flags); +#endif return 0; }
@@ -541,22 +612,32 @@ static int ima_release_policy(struct inode *inode, struct file *file) securityfs_remove(ima_policy); ima_policy = NULL; #elif defined(CONFIG_IMA_WRITE_POLICY) +#ifdef CONFIG_IMA_DIGEST_LIST + clear_bit(flag, &ima_fs_flags); +#else clear_bit(IMA_FS_BUSY, &ima_fs_flags); +#endif #elif defined(CONFIG_IMA_READ_POLICY) inode->i_mode &= ~S_IWUSR; #endif return 0; }
-static const struct file_operations ima_measure_policy_ops = { - .open = ima_open_policy, #ifdef CONFIG_IMA_DIGEST_LIST +static const struct file_operations ima_data_upload_ops = { + .open = ima_open_data_upload, .write = ima_write_data, #else +static const struct file_operations ima_measure_policy_ops = { + .open = ima_open_policy, .write = ima_write_policy, #endif .read = seq_read, +#ifdef CONFIG_IMA_DIGEST_LIST + .release = ima_release_data_upload, +#else .release = ima_release_policy, +#endif .llseek = generic_file_llseek, };
@@ -612,7 +693,11 @@ int __init ima_fs_init(void)
ima_policy = securityfs_create_file("policy", POLICY_FILE_FLAGS, ima_dir, NULL, +#ifdef CONFIG_IMA_DIGEST_LIST + &ima_data_upload_ops); +#else &ima_measure_policy_ops); +#endif if (IS_ERR(ima_policy)) { ret = PTR_ERR(ima_policy); goto out;