2023-01-31 02:03:12

by Xiu Jianfeng

Subject: [PATCH -next] evm: call dump_security_xattr() in all cases to remove code duplication

Currently dump_security_xattr() is used to dump security xattr value
which is larger than 64 bytes, otherwise, pr_debug() is used. In order
to remove code duplication, refator dump_security_xattr() and call it in
all cases.

Signed-off-by: Xiu Jianfeng <[email protected]>
---
security/integrity/evm/evm_crypto.c | 33 ++++++++++++++---------------
1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index fa5ff13fa8c9..0fe6c9cd8eab 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -183,8 +183,8 @@ static void hmac_add_misc(struct shash_desc *desc, struct inode *inode,
* Dump large security xattr values as a continuous ascii hexademical string.
* (pr_debug is limited to 64 bytes.)
*/
-static void dump_security_xattr(const char *prefix, const void *src,
- size_t count)
+static void dump_security_xattr_l(const char *prefix, const void *src,
+ size_t count)
{
#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
char *asciihex, *p;
@@ -200,6 +200,16 @@ static void dump_security_xattr(const char *prefix, const void *src,
#endif
}

+static void dump_security_xattr(const char *name, const char *value,
+ size_t value_len)
+{
+ if (value_len < 64)
+ pr_debug("%s: (%zu) [%*phN]\n", name, value_len,
+ (int)value_len, value);
+ else
+ dump_security_xattr_l(name, value, value_len);
+}
+
/*
* Calculate the HMAC value across the set of protected security xattrs.
*
@@ -254,15 +264,9 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry,
if (is_ima)
ima_present = true;

- if (req_xattr_value_len < 64)
- pr_debug("%s: (%zu) [%*phN]\n", req_xattr_name,
- req_xattr_value_len,
- (int)req_xattr_value_len,
- req_xattr_value);
- else
- dump_security_xattr(req_xattr_name,
- req_xattr_value,
- req_xattr_value_len);
+ dump_security_xattr(req_xattr_name,
+ req_xattr_value,
+ req_xattr_value_len);
continue;
}
size = vfs_getxattr_alloc(&init_user_ns, dentry, xattr->name,
@@ -286,12 +290,7 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry,
if (is_ima)
ima_present = true;

- if (xattr_size < 64)
- pr_debug("%s: (%zu) [%*phN]", xattr->name, xattr_size,
- (int)xattr_size, xattr_value);
- else
- dump_security_xattr(xattr->name, xattr_value,
- xattr_size);
+ dump_security_xattr(xattr->name, xattr_value, xattr_size);
}
hmac_add_misc(desc, inode, type, data->digest);

--
2.17.1

2023-01-31 02:11:31

by Xiu Jianfeng

Subject: Re: [PATCH -next] evm: call dump_security_xattr() in all cases to remove code duplication

sorry, I forget to add v2 tag, this is based on commit b8dc57947379
("ima: fix ima_delete_rules() kernel-doc warning").

On 2023/1/31 10:00, Xiu Jianfeng wrote:
> Currently dump_security_xattr() is used to dump security xattr value
> which is larger than 64 bytes, otherwise, pr_debug() is used. In order
> to remove code duplication, refator dump_security_xattr() and call it in
> all cases.
>
> Signed-off-by: Xiu Jianfeng <[email protected]>
> ---
> security/integrity/evm/evm_crypto.c | 33 ++++++++++++++---------------
> 1 file changed, 16 insertions(+), 17 deletions(-)
>
> diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
> index fa5ff13fa8c9..0fe6c9cd8eab 100644
> --- a/security/integrity/evm/evm_crypto.c
> +++ b/security/integrity/evm/evm_crypto.c
> @@ -183,8 +183,8 @@ static void hmac_add_misc(struct shash_desc *desc, struct inode *inode,
> * Dump large security xattr values as a continuous ascii hexademical string.
> * (pr_debug is limited to 64 bytes.)
> */
> -static void dump_security_xattr(const char *prefix, const void *src,
> - size_t count)
> +static void dump_security_xattr_l(const char *prefix, const void *src,
> + size_t count)
> {
> #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
> char *asciihex, *p;
> @@ -200,6 +200,16 @@ static void dump_security_xattr(const char *prefix, const void *src,
> #endif
> }
>
> +static void dump_security_xattr(const char *name, const char *value,
> + size_t value_len)
> +{
> + if (value_len < 64)
> + pr_debug("%s: (%zu) [%*phN]\n", name, value_len,
> + (int)value_len, value);
> + else
> + dump_security_xattr_l(name, value, value_len);
> +}
> +
> /*
> * Calculate the HMAC value across the set of protected security xattrs.
> *
> @@ -254,15 +264,9 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry,
> if (is_ima)
> ima_present = true;
>
> - if (req_xattr_value_len < 64)
> - pr_debug("%s: (%zu) [%*phN]\n", req_xattr_name,
> - req_xattr_value_len,
> - (int)req_xattr_value_len,
> - req_xattr_value);
> - else
> - dump_security_xattr(req_xattr_name,
> - req_xattr_value,
> - req_xattr_value_len);
> + dump_security_xattr(req_xattr_name,
> + req_xattr_value,
> + req_xattr_value_len);
> continue;
> }
> size = vfs_getxattr_alloc(&init_user_ns, dentry, xattr->name,
> @@ -286,12 +290,7 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry,
> if (is_ima)
> ima_present = true;
>
> - if (xattr_size < 64)
> - pr_debug("%s: (%zu) [%*phN]", xattr->name, xattr_size,
> - (int)xattr_size, xattr_value);
> - else
> - dump_security_xattr(xattr->name, xattr_value,
> - xattr_size);
> + dump_security_xattr(xattr->name, xattr_value, xattr_size);
> }
> hmac_add_misc(desc, inode, type, data->digest);
>