firmware/br-ext-chip-allwinner/board/v83x/kernel/patches/00000-security_selinux_hook...

222 lines
5.8 KiB
Diff

diff -drupN a/security/selinux/hooks.c b/security/selinux/hooks.c
--- a/security/selinux/hooks.c 2018-08-06 17:23:04.000000000 +0300
+++ b/security/selinux/hooks.c 2022-06-12 05:28:14.000000000 +0300
@@ -83,6 +83,7 @@
#include <linux/export.h>
#include <linux/msg.h>
#include <linux/shm.h>
+#include <linux/bpf.h>
#include "avc.h"
#include "objsec.h"
@@ -479,6 +480,7 @@ static int selinux_is_sblabel_mnt(struct
!strcmp(sb->s_type->name, "sysfs") ||
!strcmp(sb->s_type->name, "pstore") ||
!strcmp(sb->s_type->name, "debugfs") ||
+ !strcmp(sb->s_type->name, "tracefs") ||
!strcmp(sb->s_type->name, "rootfs");
}
@@ -797,6 +799,7 @@ static int selinux_set_mnt_opts(struct s
sbsec->flags |= SE_SBPROC | SE_SBGENFS;
if (!strcmp(sb->s_type->name, "debugfs") ||
+ !strcmp(sb->s_type->name, "tracefs") ||
!strcmp(sb->s_type->name, "sysfs") ||
!strcmp(sb->s_type->name, "pstore"))
sbsec->flags |= SE_SBGENFS;
@@ -1745,6 +1748,10 @@ static inline int file_path_has_perm(con
return inode_has_perm(cred, file_inode(file), av, &ad);
}
+#ifdef CONFIG_BPF_SYSCALL
+static int bpf_fd_pass(struct file *file, u32 sid);
+#endif
+
/* Check whether a task can use an open file descriptor to
access an inode in a given way. Check access to the
descriptor itself, and then use dentry_has_perm to
@@ -1775,6 +1782,12 @@ static int file_has_perm(const struct cr
goto out;
}
+#ifdef CONFIG_BPF_SYSCALL
+ rc = bpf_fd_pass(file, cred_sid(cred));
+ if (rc)
+ return rc;
+#endif
+
/* av is zero if only checking access to the descriptor. */
rc = 0;
if (av)
@@ -2104,6 +2117,12 @@ static int selinux_binder_transfer_file(
return rc;
}
+#ifdef CONFIG_BPF_SYSCALL
+ rc = bpf_fd_pass(file, sid);
+ if (rc)
+ return rc;
+#endif
+
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return 0;
@@ -6073,6 +6092,139 @@ static int selinux_key_getsecurity(struc
#endif
+#ifdef CONFIG_BPF_SYSCALL
+static int selinux_bpf(int cmd, union bpf_attr *attr,
+ unsigned int size)
+{
+ u32 sid = current_sid();
+ int ret;
+
+ switch (cmd) {
+ case BPF_MAP_CREATE:
+ ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__MAP_CREATE,
+ NULL);
+ break;
+ case BPF_PROG_LOAD:
+ ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__PROG_LOAD,
+ NULL);
+ break;
+ default:
+ ret = 0;
+ break;
+ }
+
+ return ret;
+}
+
+static u32 bpf_map_fmode_to_av(fmode_t fmode)
+{
+ u32 av = 0;
+
+ if (fmode & FMODE_READ)
+ av |= BPF__MAP_READ;
+ if (fmode & FMODE_WRITE)
+ av |= BPF__MAP_WRITE;
+ return av;
+}
+
+/* This function will check the file pass through unix socket or binder to see
+ * if it is a bpf related object. And apply correspinding checks on the bpf
+ * object based on the type. The bpf maps and programs, not like other files and
+ * socket, are using a shared anonymous inode inside the kernel as their inode.
+ * So checking that inode cannot identify if the process have privilege to
+ * access the bpf object and that's why we have to add this additional check in
+ * selinux_file_receive and selinux_binder_transfer_files.
+ */
+static int bpf_fd_pass(struct file *file, u32 sid)
+{
+ struct bpf_security_struct *bpfsec;
+ struct bpf_prog *prog;
+ struct bpf_map *map;
+ int ret;
+
+ if (file->f_op == &bpf_map_fops) {
+ map = file->private_data;
+ bpfsec = map->security;
+ ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
+ bpf_map_fmode_to_av(file->f_mode), NULL);
+ if (ret)
+ return ret;
+ } else if (file->f_op == &bpf_prog_fops) {
+ prog = file->private_data;
+ bpfsec = prog->aux->security;
+ ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
+ BPF__PROG_RUN, NULL);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
+static int selinux_bpf_map(struct bpf_map *map, fmode_t fmode)
+{
+ u32 sid = current_sid();
+ struct bpf_security_struct *bpfsec;
+
+ bpfsec = map->security;
+ return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
+ bpf_map_fmode_to_av(fmode), NULL);
+}
+
+static int selinux_bpf_prog(struct bpf_prog *prog)
+{
+ u32 sid = current_sid();
+ struct bpf_security_struct *bpfsec;
+
+ bpfsec = prog->aux->security;
+ return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
+ BPF__PROG_RUN, NULL);
+}
+
+static int selinux_bpf_map_alloc(struct bpf_map *map)
+{
+ struct bpf_security_struct *bpfsec;
+
+ bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
+ if (!bpfsec)
+ return -ENOMEM;
+
+ bpfsec->sid = current_sid();
+ map->security = bpfsec;
+
+ return 0;
+}
+
+static void selinux_bpf_map_free(struct bpf_map *map)
+{
+ struct bpf_security_struct *bpfsec = map->security;
+
+ map->security = NULL;
+ kfree(bpfsec);
+}
+
+static int selinux_bpf_prog_alloc(struct bpf_prog_aux *aux)
+{
+ struct bpf_security_struct *bpfsec;
+
+ bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
+ if (!bpfsec)
+ return -ENOMEM;
+
+ bpfsec->sid = current_sid();
+ aux->security = bpfsec;
+
+ return 0;
+}
+
+static void selinux_bpf_prog_free(struct bpf_prog_aux *aux)
+{
+ struct bpf_security_struct *bpfsec = aux->security;
+
+ aux->security = NULL;
+ kfree(bpfsec);
+}
+#endif
+
static struct security_hook_list selinux_hooks[] = {
LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction),
@@ -6287,6 +6439,16 @@ static struct security_hook_list selinux
LSM_HOOK_INIT(audit_rule_match, selinux_audit_rule_match),
LSM_HOOK_INIT(audit_rule_free, selinux_audit_rule_free),
#endif
+
+#ifdef CONFIG_BPF_SYSCALL
+ LSM_HOOK_INIT(bpf, selinux_bpf),
+ LSM_HOOK_INIT(bpf_map, selinux_bpf_map),
+ LSM_HOOK_INIT(bpf_prog, selinux_bpf_prog),
+ LSM_HOOK_INIT(bpf_map_alloc_security, selinux_bpf_map_alloc),
+ LSM_HOOK_INIT(bpf_prog_alloc_security, selinux_bpf_prog_alloc),
+ LSM_HOOK_INIT(bpf_map_free_security, selinux_bpf_map_free),
+ LSM_HOOK_INIT(bpf_prog_free_security, selinux_bpf_prog_free),
+#endif
};
static __init int selinux_init(void)