Merge #1718

1718: Prevent panic when min > static bound and max is less than it r=MarkMcCaskey a=MarkMcCaskey This change should be safe because we check that min <= max when actually making the memory, so this assert can never fire and produce a `MemoryStyle` that would let us create a memory. This PR also tests a lot more edge cases of memory creation in the C API. Resolves the issue brought up here #1631 (comment) # Review - [x] Add a short description of the the change to the CHANGELOG.md file Co-authored-by: Mark McCaskey <[email protected]> Co-authored-by: Mark McCaskey <[email protected]>
wasmerio · Oct 15, 2020 · e65be6e · e65be6e
2 parents 193d7c8 + f3bcc36
commit e65be6e
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -13,6 +13,10 @@
 - [#1709](https://github.com/wasmerio/wasmer/pull/1709) Implement `wasm_module_name` and `wasm_module_set_name` in the Wasm(er) C API.
 - [#1700](https://github.com/wasmerio/wasmer/pull/1700) Implement `wasm_externtype_copy` in the Wasm C API.
 
+### Fixed
+
+- [#1718](https://github.com/wasmerio/wasmer/pull/1718) Fix panic in the API in some situations when the memory's min bound was greater than the memory's max bound.
+
 ## 1.0.0-alpha4 - 2020-10-08
 
 ### Added

diff --git a/lib/api/src/tunables.rs b/lib/api/src/tunables.rs
@@ -1,5 +1,4 @@
 use crate::{MemoryType, Pages, TableType};
-use more_asserts::assert_ge;
 use std::cmp::min;
 use std::sync::Arc;
 use target_lexicon::{OperatingSystem, PointerWidth};
@@ -67,7 +66,6 @@ impl BaseTunables for Tunables {
         // If the module doesn't declare an explicit maximum treat it as 4GiB.
         let maximum = memory.maximum.unwrap_or_else(Pages::max_value);
         if maximum <= self.static_memory_bound {
-            assert_ge!(self.static_memory_bound, memory.minimum);
             MemoryStyle::Static {
                 bound: self.static_memory_bound,
                 offset_guard_size: self.static_memory_offset_guard_size,

diff --git a/lib/c-api/tests/wasm_c_api/test-memory.c b/lib/c-api/tests/wasm_c_api/test-memory.c
@@ -62,6 +62,66 @@ int main(int argc, const char *argv[]) {
   wasm_memorytype_delete(memtype3);
   wasm_memory_delete(memory3);
 
+  // =====================
+  wasm_limits_t limits4 = {
+    .min = 0x7FFFFFFF,
+    .max = 0x7FFFFFFF,
+  };
+  own wasm_memorytype_t* memtype4 = wasm_memorytype_new(&limits4);
+  own wasm_memory_t* memory4 = wasm_memory_new(store, memtype4);
+  assert(memory4 == NULL);
+  error = get_wasmer_error();
+  printf("Found error string: %s\n", error);
+  assert(0 == strcmp("The minimum requested (2147483647 pages) memory is greater than the maximum allowed memory (65536 pages)", error));
+  free(error);
+
+  wasm_memorytype_delete(memtype4);
+
+  // =====================
+  wasm_limits_t limits5 = {
+    .min = 0x7FFFFFFF,
+    .max = 0x0FFFFFFF,
+  };
+  own wasm_memorytype_t* memtype5 = wasm_memorytype_new(&limits5);
+  own wasm_memory_t* memory5 = wasm_memory_new(store, memtype5);
+  assert(memory5 == NULL);
+  error = get_wasmer_error();
+  printf("Found error string: %s\n", error);
+  assert(0 == strcmp("The minimum requested (2147483647 pages) memory is greater than the maximum allowed memory (65536 pages)", error));
+  free(error);
+
+  wasm_memorytype_delete(memtype5);
+
+  // =====================
+  wasm_limits_t limits6 = {
+    .min = 15,
+    .max = 10,
+  };
+  own wasm_memorytype_t* memtype6 = wasm_memorytype_new(&limits6);
+  own wasm_memory_t* memory6 = wasm_memory_new(store, memtype6);
+  assert(memory6 == NULL);
+  error = get_wasmer_error();
+  printf("Found error string: %s\n", error);
+  assert(0 == strcmp("The memory is invalid because the maximum (10 pages) is less than the minimum (15 pages)", error));
+  free(error);
+
+  wasm_memorytype_delete(memtype6);
+
+  // =====================
+  wasm_limits_t limits7 = {
+    .min = 0x7FFFFFFF,
+    .max = 10,
+  };
+  own wasm_memorytype_t* memtype7 = wasm_memorytype_new(&limits7);
+  own wasm_memory_t* memory7 = wasm_memory_new(store, memtype7);
+  assert(memory7 == NULL);
+  error = get_wasmer_error();
+  printf("Found error string: %s\n", error);
+  assert(0 == strcmp("The minimum requested (2147483647 pages) memory is greater than the maximum allowed memory (65536 pages)", error));
+  free(error);
+
+  wasm_memorytype_delete(memtype7);
+
   printf("Shutting down...\n");
   wasm_store_delete(store);
   wasm_engine_delete(engine);