4 files changed, 72 insertions, 16 deletions

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index c2cb1b5c094e..8390859e79e7 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -385,16 +385,16 @@ static inline void __dev_map_flush(struct bpf_map *map)
 
 #if defined(CONFIG_STREAM_PARSER) && defined(CONFIG_BPF_SYSCALL)
 struct sock  *__sock_map_lookup_elem(struct bpf_map *map, u32 key);
-int sock_map_attach_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type);
+int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type);
 #else
 static inline struct sock  *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
 {
         return NULL;
 }
 
-static inline int sock_map_attach_prog(struct bpf_map *map,
-                                       struct bpf_prog *prog,
-                                       u32 type)
+static inline int sock_map_prog(struct bpf_map *map,
+                                struct bpf_prog *prog,
+                                u32 type)
 {
         return -EOPNOTSUPP;
 }
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index f6ffde9c6a68..6424ce0e4969 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -792,7 +792,7 @@ out_progs:
         return err;
 }
 
-int sock_map_attach_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type)
+int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type)
 {
         struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
         struct bpf_prog *orig;
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 70ad8e220343..cb17e1cd1d43 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1096,10 +1096,10 @@ static int bpf_obj_get(const union bpf_attr *attr)
 
 #define BPF_PROG_ATTACH_LAST_FIELD attach_flags
 
-static int sockmap_get_from_fd(const union bpf_attr *attr)
+static int sockmap_get_from_fd(const union bpf_attr *attr, bool attach)
 {
+        struct bpf_prog *prog = NULL;
         int ufd = attr->target_fd;
-        struct bpf_prog *prog;
         struct bpf_map *map;
         struct fd f;
         int err;
@@ -1109,16 +1109,20 @@ static int sockmap_get_from_fd(const union bpf_attr *attr)
         if (IS_ERR(map))
                 return PTR_ERR(map);
 
-        prog = bpf_prog_get_type(attr->attach_bpf_fd, BPF_PROG_TYPE_SK_SKB);
-        if (IS_ERR(prog)) {
-                fdput(f);
-                return PTR_ERR(prog);
+        if (attach) {
+                prog = bpf_prog_get_type(attr->attach_bpf_fd,
+                                         BPF_PROG_TYPE_SK_SKB);
+                if (IS_ERR(prog)) {
+                        fdput(f);
+                        return PTR_ERR(prog);
+                }
         }
 
-        err = sock_map_attach_prog(map, prog, attr->attach_type);
+        err = sock_map_prog(map, prog, attr->attach_type);
         if (err) {
                 fdput(f);
-                bpf_prog_put(prog);
+                if (prog)
+                        bpf_prog_put(prog);
                 return err;
         }
 
@@ -1155,7 +1159,7 @@ static int bpf_prog_attach(const union bpf_attr *attr)
                 break;
         case BPF_SK_SKB_STREAM_PARSER:
         case BPF_SK_SKB_STREAM_VERDICT:
-                return sockmap_get_from_fd(attr);
+                return sockmap_get_from_fd(attr, true);
         default:
                 return -EINVAL;
         }
@@ -1204,7 +1208,10 @@ static int bpf_prog_detach(const union bpf_attr *attr)
                 ret = cgroup_bpf_update(cgrp, NULL, attr->attach_type, false);
                 cgroup_put(cgrp);
                 break;
-
+        case BPF_SK_SKB_STREAM_PARSER:
+        case BPF_SK_SKB_STREAM_VERDICT:
+                ret = sockmap_get_from_fd(attr, false);
+                break;
         default:
                 return -EINVAL;
         }
diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
index 4acc772a28c0..fe3a443a1102 100644
--- a/tools/testing/selftests/bpf/test_maps.c
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -558,7 +558,7 @@ static void test_sockmap(int tasks, void *data)
                 }
         }
 
-        /* Test attaching bad fds */
+        /* Test attaching/detaching bad fds */
         err = bpf_prog_attach(-1, fd, BPF_SK_SKB_STREAM_PARSER, 0);
         if (!err) {
                 printf("Failed invalid parser prog attach\n");
@@ -571,6 +571,30 @@ static void test_sockmap(int tasks, void *data)
                 goto out_sockmap;
         }
 
+        err = bpf_prog_attach(-1, fd, __MAX_BPF_ATTACH_TYPE, 0);
+        if (!err) {
+                printf("Failed unknown prog attach\n");
+                goto out_sockmap;
+        }
+
+        err = bpf_prog_detach(fd, BPF_SK_SKB_STREAM_PARSER);
+        if (err) {
+                printf("Failed empty parser prog detach\n");
+                goto out_sockmap;
+        }
+
+        err = bpf_prog_detach(fd, BPF_SK_SKB_STREAM_VERDICT);
+        if (err) {
+                printf("Failed empty verdict prog detach\n");
+                goto out_sockmap;
+        }
+
+        err = bpf_prog_detach(fd, __MAX_BPF_ATTACH_TYPE);
+        if (!err) {
+                printf("Detach invalid prog successful\n");
+                goto out_sockmap;
+        }
+
         /* Load SK_SKB program and Attach */
         err = bpf_prog_load(SOCKMAP_PARSE_PROG,
                             BPF_PROG_TYPE_SK_SKB, &obj, &parse_prog);
@@ -643,6 +667,13 @@ static void test_sockmap(int tasks, void *data)
                 goto out_sockmap;
         }
 
+        err = bpf_prog_attach(verdict_prog, map_fd_rx,
+                              __MAX_BPF_ATTACH_TYPE, 0);
+        if (!err) {
+                printf("Attached unknown bpf prog\n");
+                goto out_sockmap;
+        }
+
         /* Test map update elem afterwards fd lives in fd and map_fd */
         for (i = 0; i < 6; i++) {
                 err = bpf_map_update_elem(map_fd_rx, &i, &sfd[i], BPF_ANY);
@@ -809,6 +840,24 @@ static void test_sockmap(int tasks, void *data)
                 assert(status == 0);
         }
 
+        err = bpf_prog_detach(map_fd_rx, __MAX_BPF_ATTACH_TYPE);
+        if (!err) {
+                printf("Detached an invalid prog type.\n");
+                goto out_sockmap;
+        }
+
+        err = bpf_prog_detach(map_fd_rx, BPF_SK_SKB_STREAM_PARSER);
+        if (err) {
+                printf("Failed parser prog detach\n");
+                goto out_sockmap;
+        }
+
+        err = bpf_prog_detach(map_fd_rx, BPF_SK_SKB_STREAM_VERDICT);
+        if (err) {
+                printf("Failed parser prog detach\n");
+                goto out_sockmap;
+        }
+
         /* Test map close sockets */
         for (i = 0; i < 6; i++)
                 close(sfd[i]);