3 files changed, 48 insertions, 18 deletions

diff --git a/include/linux/asn1_ber_bytecode.h b/include/linux/asn1_ber_bytecode.h
index 945d44ae529c..ab3a6c002f7b 100644
--- a/include/linux/asn1_ber_bytecode.h
+++ b/include/linux/asn1_ber_bytecode.h
@@ -45,23 +45,27 @@ enum asn1_opcode {
         ASN1_OP_MATCH_JUMP              = 0x04,
         ASN1_OP_MATCH_JUMP_OR_SKIP      = 0x05,
         ASN1_OP_MATCH_ANY               = 0x08,
+        ASN1_OP_MATCH_ANY_OR_SKIP       = 0x09,
         ASN1_OP_MATCH_ANY_ACT           = 0x0a,
+        ASN1_OP_MATCH_ANY_ACT_OR_SKIP   = 0x0b,
         /* Everything before here matches unconditionally */
 
         ASN1_OP_COND_MATCH_OR_SKIP      = 0x11,
         ASN1_OP_COND_MATCH_ACT_OR_SKIP  = 0x13,
         ASN1_OP_COND_MATCH_JUMP_OR_SKIP = 0x15,
         ASN1_OP_COND_MATCH_ANY          = 0x18,
+        ASN1_OP_COND_MATCH_ANY_OR_SKIP  = 0x19,
         ASN1_OP_COND_MATCH_ANY_ACT      = 0x1a,
+        ASN1_OP_COND_MATCH_ANY_ACT_OR_SKIP = 0x1b,
 
         /* Everything before here will want a tag from the data */
-#define ASN1_OP__MATCHES_TAG ASN1_OP_COND_MATCH_ANY_ACT
+#define ASN1_OP__MATCHES_TAG ASN1_OP_COND_MATCH_ANY_ACT_OR_SKIP
 
         /* These are here to help fill up space */
-        ASN1_OP_COND_FAIL               = 0x1b,
-        ASN1_OP_COMPLETE                = 0x1c,
-        ASN1_OP_ACT                     = 0x1d,
-        ASN1_OP_RETURN                  = 0x1e,
+        ASN1_OP_COND_FAIL               = 0x1c,
+        ASN1_OP_COMPLETE                = 0x1d,
+        ASN1_OP_ACT                     = 0x1e,
+        ASN1_OP_MAYBE_ACT               = 0x1f,
 
         /* The following eight have bit 0 -> SET, 1 -> OF, 2 -> ACT */
         ASN1_OP_END_SEQ                 = 0x20,
@@ -76,6 +80,8 @@ enum asn1_opcode {
 #define ASN1_OP_END__OF                   0x02
 #define ASN1_OP_END__ACT                  0x04
 
+        ASN1_OP_RETURN                  = 0x28,
+
         ASN1_OP__NR
 };
 
diff --git a/lib/asn1_decoder.c b/lib/asn1_decoder.c
index 1a000bb050f9..2b3f46c049d4 100644
--- a/lib/asn1_decoder.c
+++ b/lib/asn1_decoder.c
@@ -24,15 +24,20 @@ static const unsigned char asn1_op_lengths[ASN1_OP__NR] = {
         [ASN1_OP_MATCH_JUMP]                    = 1 + 1 + 1,
         [ASN1_OP_MATCH_JUMP_OR_SKIP]            = 1 + 1 + 1,
         [ASN1_OP_MATCH_ANY]                     = 1,
+        [ASN1_OP_MATCH_ANY_OR_SKIP]             = 1,
         [ASN1_OP_MATCH_ANY_ACT]                 = 1         + 1,
+        [ASN1_OP_MATCH_ANY_ACT_OR_SKIP]         = 1         + 1,
         [ASN1_OP_COND_MATCH_OR_SKIP]            = 1 + 1,
         [ASN1_OP_COND_MATCH_ACT_OR_SKIP]        = 1 + 1     + 1,
         [ASN1_OP_COND_MATCH_JUMP_OR_SKIP]       = 1 + 1 + 1,
         [ASN1_OP_COND_MATCH_ANY]                = 1,
+        [ASN1_OP_COND_MATCH_ANY_OR_SKIP]        = 1,
         [ASN1_OP_COND_MATCH_ANY_ACT]            = 1         + 1,
+        [ASN1_OP_COND_MATCH_ANY_ACT_OR_SKIP]    = 1         + 1,
         [ASN1_OP_COND_FAIL]                     = 1,
         [ASN1_OP_COMPLETE]                      = 1,
         [ASN1_OP_ACT]                           = 1         + 1,
+        [ASN1_OP_MAYBE_ACT]                     = 1         + 1,
         [ASN1_OP_RETURN]                        = 1,
         [ASN1_OP_END_SEQ]                       = 1,
         [ASN1_OP_END_SEQ_OF]                    = 1     + 1,
@@ -177,6 +182,7 @@ int asn1_ber_decoder(const struct asn1_decoder *decoder,
         unsigned char flags = 0;
 #define FLAG_INDEFINITE_LENGTH  0x01
 #define FLAG_MATCHED            0x02
+#define FLAG_LAST_MATCHED       0x04 /* Last tag matched */
 #define FLAG_CONS               0x20 /* Corresponds to CONS bit in the opcode tag
                                       * - ie. whether or not we are going to parse
                                       *   a compound type.
@@ -208,9 +214,9 @@ next_op:
                 unsigned char tmp;
 
                 /* Skip conditional matches if possible */
-                if ((op & ASN1_OP_MATCH__COND &&
-                     flags & FLAG_MATCHED) ||
-                    dp == datalen) {
+                if ((op & ASN1_OP_MATCH__COND && flags & FLAG_MATCHED) ||
+                    (op & ASN1_OP_MATCH__SKIP && dp == datalen)) {
+                        flags &= ~FLAG_LAST_MATCHED;
                         pc += asn1_op_lengths[op];
                         goto next_op;
                 }
@@ -302,7 +308,9 @@ next_op:
         /* Decide how to handle the operation */
         switch (op) {
         case ASN1_OP_MATCH_ANY_ACT:
+        case ASN1_OP_MATCH_ANY_ACT_OR_SKIP:
         case ASN1_OP_COND_MATCH_ANY_ACT:
+        case ASN1_OP_COND_MATCH_ANY_ACT_OR_SKIP:
                 ret = actions[machine[pc + 1]](context, hdr, tag, data + dp, len);
                 if (ret < 0)
                         return ret;
@@ -319,8 +327,10 @@ next_op:
         case ASN1_OP_MATCH:
         case ASN1_OP_MATCH_OR_SKIP:
         case ASN1_OP_MATCH_ANY:
+        case ASN1_OP_MATCH_ANY_OR_SKIP:
         case ASN1_OP_COND_MATCH_OR_SKIP:
         case ASN1_OP_COND_MATCH_ANY:
+        case ASN1_OP_COND_MATCH_ANY_OR_SKIP:
         skip_data:
                 if (!(flags & FLAG_CONS)) {
                         if (flags & FLAG_INDEFINITE_LENGTH) {
@@ -422,8 +432,15 @@ next_op:
                 pc += asn1_op_lengths[op];
                 goto next_op;
 
+        case ASN1_OP_MAYBE_ACT:
+                if (!(flags & FLAG_LAST_MATCHED)) {
+                        pc += asn1_op_lengths[op];
+                        goto next_op;
+                }
         case ASN1_OP_ACT:
                 ret = actions[machine[pc + 1]](context, hdr, tag, data + tdp, len);
+                if (ret < 0)
+                        return ret;
                 pc += asn1_op_lengths[op];
                 goto next_op;
 
@@ -431,6 +448,7 @@ next_op:
                 if (unlikely(jsp <= 0))
                         goto jump_stack_underflow;
                 pc = jump_stack[--jsp];
+                flags |= FLAG_MATCHED | FLAG_LAST_MATCHED;
                 goto next_op;
 
         default:
@@ -438,7 +456,8 @@ next_op:
         }
 
         /* Shouldn't reach here */
-        pr_err("ASN.1 decoder error: Found reserved opcode (%u)\n", op);
+        pr_err("ASN.1 decoder error: Found reserved opcode (%u) pc=%zu\n",
+               op, pc);
         return -EBADMSG;
 
 data_overrun_error:
diff --git a/scripts/asn1_compiler.c b/scripts/asn1_compiler.c
index 7750e9c31483..1c75e22b6385 100644
--- a/scripts/asn1_compiler.c
+++ b/scripts/asn1_compiler.c
@@ -666,7 +666,7 @@ struct element {
         unsigned        flags;
 #define ELEMENT_IMPLICIT        0x0001
 #define ELEMENT_EXPLICIT        0x0002
-#define ELEMENT_MARKED          0x0004
+#define ELEMENT_TAG_SPECIFIED   0x0004
 #define ELEMENT_RENDERED        0x0008
 #define ELEMENT_SKIPPABLE       0x0010
 #define ELEMENT_CONDITIONAL     0x0020
@@ -879,6 +879,7 @@ static struct element *parse_type(struct token **_cursor, struct token *end,
 
                 element->tag &= ~0x1f;
                 element->tag |= strtoul(cursor->value, &p, 10);
+                element->flags |= ELEMENT_TAG_SPECIFIED;
                 if (p - cursor->value != cursor->size)
                         abort();
                 cursor++;
@@ -1376,7 +1377,7 @@ static void render_out_of_line_list(FILE *out)
  */
 static void render_element(FILE *out, struct element *e, struct element *tag)
 {
-        struct element *ec;
+        struct element *ec, *x;
         const char *cond, *act;
         int entry, skippable = 0, outofline = 0;
 
@@ -1400,7 +1401,8 @@ static void render_element(FILE *out, struct element *e, struct element *tag)
         act = e->action ? "_ACT" : "";
         switch (e->compound) {
         case ANY:
-                render_opcode(out, "ASN1_OP_%sMATCH_ANY%s,", cond, act);
+                render_opcode(out, "ASN1_OP_%sMATCH_ANY%s%s,",
+                              cond, act, skippable ? "_OR_SKIP" : "");
                 if (e->name)
                         render_more(out, "\t\t// %*.*s",
                                     (int)e->name->size, (int)e->name->size,
@@ -1435,15 +1437,17 @@ static void render_element(FILE *out, struct element *e, struct element *tag)
                 break;
         }
 
-        if (e->name)
+        x = tag ?: e;
+        if (x->name)
                 render_more(out, "\t\t// %*.*s",
-                            (int)e->name->size, (int)e->name->size,
-                            e->name->value);
+                            (int)x->name->size, (int)x->name->size,
+                            x->name->value);
         render_more(out, "\n");
 
         /* Render the tag */
-        if (!tag)
+        if (!tag || !(tag->flags & ELEMENT_TAG_SPECIFIED))
                 tag = e;
+
         if (tag->class == ASN1_UNIV &&
             tag->tag != 14 &&
             tag->tag != 15 &&
@@ -1465,7 +1469,8 @@ dont_render_tag:
         case TYPE_REF:
                 render_element(out, e->type->type->element, tag);
                 if (e->action)
-                        render_opcode(out, "ASN1_OP_ACT,\n");
+                        render_opcode(out, "ASN1_OP_%sACT,\n",
+                                      skippable ? "MAYBE_" : "");
                 break;
 
         case SEQUENCE:
@@ -1539,7 +1544,7 @@ dont_render_tag:
 
         case CHOICE:
                 for (ec = e->children; ec; ec = ec->next)
-                        render_element(out, ec, NULL);
+                        render_element(out, ec, ec);
                 if (!skippable)
                         render_opcode(out, "ASN1_OP_COND_FAIL,\n");
                 if (e->action)