@@ -1443,26 +1443,29 @@ late_initcall(bpf_key_sig_kfuncs_init);
__bpf_kfunc_start_defs();
/**
- * bpf_get_file_xattr - get xattr of a file
- * @file: file to get xattr from
+ * bpf_get_dentry_xattr - get xattr of a dentry
+ * @dentry: dentry to get xattr from
* @name__str: name of the xattr
* @value_p: output buffer of the xattr value
*
- * Get xattr *name__str* of *file* and store the output in *value_ptr*.
+ * Get xattr *name__str* of *dentry* and store the output in *value_ptr*.
*
* For security reasons, only *name__str* with prefix "user." is allowed.
*
* Return: 0 on success, a negative value on error.
*/
-__bpf_kfunc int bpf_get_file_xattr(struct file *file, const char *name__str,
- struct bpf_dynptr *value_p)
+__bpf_kfunc int bpf_get_dentry_xattr(struct dentry *dentry, const char *name__str,
+ struct bpf_dynptr *value_p)
{
struct bpf_dynptr_kern *value_ptr = (struct bpf_dynptr_kern *)value_p;
- struct dentry *dentry;
+ struct inode *inode = d_inode(dentry);
u32 value_len;
void *value;
int ret;
+ if (WARN_ON(!inode))
+ return -EINVAL;
+
if (strncmp(name__str, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
return -EPERM;
@@ -1471,20 +1474,41 @@ __bpf_kfunc int bpf_get_file_xattr(struct file *file, const char *name__str,
if (!value)
return -EINVAL;
- dentry = file_dentry(file);
- ret = inode_permission(&nop_mnt_idmap, dentry->d_inode, MAY_READ);
+ ret = inode_permission(&nop_mnt_idmap, inode, MAY_READ);
if (ret)
return ret;
- return __vfs_getxattr(dentry, dentry->d_inode, name__str, value, value_len);
+ return __vfs_getxattr(dentry, inode, name__str, value, value_len);
+}
+
+/**
+ * bpf_get_file_xattr - get xattr of a file
+ * @file: file to get xattr from
+ * @name__str: name of the xattr
+ * @value_p: output buffer of the xattr value
+ *
+ * Get xattr *name__str* of *file* and store the output in *value_ptr*.
+ *
+ * For security reasons, only *name__str* with prefix "user." is allowed.
+ *
+ * Return: 0 on success, a negative value on error.
+ */
+__bpf_kfunc int bpf_get_file_xattr(struct file *file, const char *name__str,
+ struct bpf_dynptr *value_p)
+{
+ struct dentry *dentry;
+
+ dentry = file_dentry(file);
+ return bpf_get_dentry_xattr(dentry, name__str, value_p);
}
__bpf_kfunc_end_defs();
BTF_KFUNCS_START(fs_kfunc_set_ids)
+BTF_ID_FLAGS(func, bpf_get_dentry_xattr, KF_SLEEPABLE | KF_TRUSTED_ARGS)
BTF_ID_FLAGS(func, bpf_get_file_xattr, KF_SLEEPABLE | KF_TRUSTED_ARGS)
BTF_KFUNCS_END(fs_kfunc_set_ids)
-static int bpf_get_file_xattr_filter(const struct bpf_prog *prog, u32 kfunc_id)
+static int fs_kfunc_filter(const struct bpf_prog *prog, u32 kfunc_id)
{
if (!btf_id_set8_contains(&fs_kfunc_set_ids, kfunc_id))
return 0;
@@ -1496,7 +1520,7 @@ static int bpf_get_file_xattr_filter(const struct bpf_prog *prog, u32 kfunc_id)
static const struct btf_kfunc_id_set bpf_fs_kfunc_set = {
.owner = THIS_MODULE,
.set = &fs_kfunc_set_ids,
- .filter = bpf_get_file_xattr_filter,
+ .filter = fs_kfunc_filter,
};
static int __init bpf_fs_kfuncs_init(void)
This kfunc can be used in LSM hooks with dentry, such as: security_inode_listxattr security_inode_permission and many more. Signed-off-by: Song Liu <song@kernel.org> --- kernel/trace/bpf_trace.c | 46 ++++++++++++++++++++++++++++++---------- 1 file changed, 35 insertions(+), 11 deletions(-)