fix: catch FormatException in log formatters to prevent third-party logger crashes#8070
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Aaronontheweb merged 3 commits intoMar 3, 2026
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…-party logger crashes Bad format strings (e.g., mismatched positional args) caused FormatException to propagate through ShouldTryKeepMessage() and crash third-party logging actors like SerilogLogger and NLogLogger. The existing catch in StandardOutLogger.PrintLogEvent() only protected the console logger. Now FormatException is caught at the formatter level in both SemanticLogMessageFormatter and DefaultLogMessageFormatter, returning a diagnostic string with the raw format and args. Defense-in-depth catches are also added in LogFilterEvaluator.ShouldTryKeepMessage() to protect against custom formatters that may throw.
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…-party logger crashes (akkadotnet#8070) Bad format strings (e.g., mismatched positional args) caused FormatException to propagate through ShouldTryKeepMessage() and crash third-party logging actors like SerilogLogger and NLogLogger. The existing catch in StandardOutLogger.PrintLogEvent() only protected the console logger. Now FormatException is caught at the formatter level in both SemanticLogMessageFormatter and DefaultLogMessageFormatter, returning a diagnostic string with the raw format and args. Defense-in-depth catches are also added in LogFilterEvaluator.ShouldTryKeepMessage() to protect against custom formatters that may throw. Co-authored-by: Gregorius Soedharmo <arkatufus@yahoo.com> (cherry picked from commit 0f35ad7)
Aaronontheweb
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…-party logger crashes (#8070) (#8073) Bad format strings (e.g., mismatched positional args) caused FormatException to propagate through ShouldTryKeepMessage() and crash third-party logging actors like SerilogLogger and NLogLogger. The existing catch in StandardOutLogger.PrintLogEvent() only protected the console logger. Now FormatException is caught at the formatter level in both SemanticLogMessageFormatter and DefaultLogMessageFormatter, returning a diagnostic string with the raw format and args. Defense-in-depth catches are also added in LogFilterEvaluator.ShouldTryKeepMessage() to protect against custom formatters that may throw. (cherry picked from commit 0f35ad7) Co-authored-by: Aaron Stannard <aaron@aaronstannard.com>
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Summary
FormatExceptioninSemanticLogMessageFormatterandDefaultLogMessageFormatterpositional format paths, returning a diagnostic string ([INVALID LOG FORMAT] str=[...], args=[...]) instead of throwingFormatExceptioncatches inLogFilterEvaluator.ShouldTryKeepMessage()to protect against custom formatters that may throwProblem
Bad format strings (e.g.,
"{0} {1} {2}"with only 2 args) causedFormatExceptionto propagate throughShouldTryKeepMessage()and crash third-party logging actors (Serilog, NLog, etc.). The existing catch inStandardOutLogger.PrintLogEvent()only protected the console logger.Stack trace from customer report:
Test plan
SemanticLogMessageFormatterreturns diagnostic for mismatched positional args (bothobject[]andIReadOnlyListpaths)DefaultLogMessageFormatterreturns diagnostic for mismatched positional argsLogFilterEvaluator(empty and content-filter paths) handlesFormatExceptiongracefullyLoggerSpectests updated and passing