getsentry · philipphofmann · Dec 22, 2022 · Dec 22, 2022 · Dec 22, 2022 · Dec 22, 2022
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+### Fixes
+
+- Crash in SentryOutOfMemoryScopeObserver (#2557)
+
 ## 7.31.4
 
 ### Fixes

diff --git a/Sources/Sentry/SentryOutOfMemoryScopeObserver.m b/Sources/Sentry/SentryOutOfMemoryScopeObserver.m
@@ -75,15 +75,22 @@ - (void)switchFileHandle
 
 - (void)store:(NSData *)data
 {
-    [self.fileHandle seekToEndOfFile];
-    [self.fileHandle writeData:data];
-    [self.fileHandle writeData:[@"\n" dataUsingEncoding:NSASCIIStringEncoding]];
-
-    self.breadcrumbCounter += 1;
-
-    if (self.breadcrumbCounter >= self.maxBreadcrumbs) {
-        [self switchFileHandle];
-        self.breadcrumbCounter = 0;
+    unsigned long long fileSize;
+    @try {
+        fileSize = [self.fileHandle seekToEndOfFile];
+
+        [self.fileHandle writeData:data];
+        [self.fileHandle writeData:[@"\n" dataUsingEncoding:NSASCIIStringEncoding]];
+
+        self.breadcrumbCounter += 1;
+    } @catch (NSException *exception) {
+        SENTRY_LOG_ERROR(@"Error while writing data to end file with size (%llu): %@ ", fileSize,
+            exception.description);
+    } @finally {
+        if (self.breadcrumbCounter >= self.maxBreadcrumbs) {
+            [self switchFileHandle];
+            self.breadcrumbCounter = 0;
+        }
     }
 }
 

diff --git a/Sources/Sentry/include/SentryOutOfMemoryScopeObserver.h b/Sources/Sentry/include/SentryOutOfMemoryScopeObserver.h
@@ -5,8 +5,12 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
-/// This scope observer is used by the Out of Memory integration to write breadcrumbs to disk.
-/// The overhead is ~0.015 seconds for 1000 breadcrumbs.
+/**
+ * This scope observer is used by the Out of Memory integration to write breadcrumbs to disk.
+ * The overhead is ~0.015 seconds for 1000 breadcrumbs.
+ * This class doesn't need to be thread safe as the scope already calls the scope observers in a
+ * thread safe manner.
+ */
 @interface SentryOutOfMemoryScopeObserver : NSObject <SentryScopeObserver>
 SENTRY_NO_INIT
 

diff --git a/Tests/SentryTests/Integrations/OutOfMemory/SentryOutOfMemoryScopeObserverTests.swift b/Tests/SentryTests/Integrations/OutOfMemory/SentryOutOfMemoryScopeObserverTests.swift
@@ -1,17 +1,22 @@
 import XCTest
 
 class SentryOutOfMemoryScopeObserverTests: XCTestCase {
+
+    private static let dsn = TestConstants.dsnAsString(username: "SentryOutOfMemoryScopeObserverTests")
+
     private class Fixture {
         let breadcrumb: Breadcrumb
         let options: Options
         let fileManager: SentryFileManager
         let currentDate = TestCurrentDateProvider()
+        let maxBreadcrumbs = 10
 
         init() {
             breadcrumb = TestData.crumb
             breadcrumb.data = nil
 
             options = Options()
+            options.dsn = SentryOutOfMemoryScopeObserverTests.dsn
             fileManager = try! SentryFileManager(options: options, andCurrentDateProvider: currentDate)
         }
 
@@ -20,7 +25,7 @@ class SentryOutOfMemoryScopeObserverTests: XCTestCase {
         }
 
         func getSut(fileManager: SentryFileManager) -> SentryOutOfMemoryScopeObserver {
-            return SentryOutOfMemoryScopeObserver(maxBreadcrumbs: 10, fileManager: fileManager)
+            return SentryOutOfMemoryScopeObserver(maxBreadcrumbs: maxBreadcrumbs, fileManager: fileManager)
         }
     }
 
@@ -85,7 +90,7 @@ class SentryOutOfMemoryScopeObserverTests: XCTestCase {
         XCTAssertEqual(fileTwoLines.count, 1)
 
         // Store 10 more
-        for _ in 0..<10 {
+        for _ in 0..<fixture.maxBreadcrumbs {
             sut.addSerializedBreadcrumb(breadcrumb)
         }
 
@@ -118,4 +123,34 @@ class SentryOutOfMemoryScopeObserverTests: XCTestCase {
 
         XCTAssertFalse(FileManager.default.fileExists(atPath: fixture.fileManager.breadcrumbsFilePathTwo))
     }
+
+    func testWritingToClosedFile() {
+        let breadcrumb = fixture.breadcrumb.serialize() as! [String: String]
+
+        sut.addSerializedBreadcrumb(breadcrumb)
+
+        let fileHandle = Dynamic(sut).fileHandle.asObject as! FileHandle
+        fileHandle.closeFile()
+
+        sut.addSerializedBreadcrumb(breadcrumb)
+
+        fixture.fileManager.moveBreadcrumbsToPreviousBreadcrumbs()
+        XCTAssertEqual(1, fixture.fileManager.readPreviousBreadcrumbs().count)
+    }
+
+    func testWritingToFullFileSystem() {
+        let breadcrumb = fixture.breadcrumb.serialize() as! [String: String]
+
+        sut.addSerializedBreadcrumb(breadcrumb)
+
+        // "/dev/urandom" simulates a bad file descriptor
+        let fileHandle = FileHandle(forReadingAtPath: "/dev/urandom")
+        Dynamic(sut).fileHandle = fileHandle
+
+        sut.addSerializedBreadcrumb(breadcrumb)
+
+        fixture.fileManager.moveBreadcrumbsToPreviousBreadcrumbs()
+        XCTAssertEqual(1, fixture.fileManager.readPreviousBreadcrumbs().count)
+    }
+
 }
diff --git a/Tests/SentryTests/Integrations/SentryCrash/SentryCrashScopeObserverTests.swift b/Tests/SentryTests/Integrations/SentryCrash/SentryCrashScopeObserverTests.swift
@@ -297,7 +297,7 @@ class SentryCrashScopeObserverTests: XCTestCase {
         return jsonPointer!.pointee
     }
 
-    private func getScopeJson(getField: (SentryCrashScope)-> UnsafeMutablePointer<CChar>?) -> String? {
+    private func getScopeJson(getField: (SentryCrashScope) -> UnsafeMutablePointer<CChar>?) -> String? {
         guard let scopePointer = sentrycrash_scopesync_getScope() else {
             return nil
         }

diff --git a/Tests/SentryTests/SentryScopeSwiftTests.swift b/Tests/SentryTests/SentryScopeSwiftTests.swift
@@ -221,7 +221,7 @@ class SentryScopeSwiftTests: XCTestCase {
 
     func testUseSpanForClear() {
         fixture.scope.span = fixture.transaction
-        fixture.scope.useSpan { (span) in
+        fixture.scope.useSpan { (_) in
             self.fixture.scope.span = nil
         }
         XCTAssertNil(fixture.scope.span)