Guard against two DoS crashes: parser recursion depth and integer div/mod by zero - #92
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Guard against two DoS crashes: parser recursion depth and integer div/mod by zero#92stratomarco wants to merge 1 commit into
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…/mod by zero
Add a recursion depth cap in Parser::parseExpression. Deeply-nested expressions
previously recursed through the expression-precedence chain without bound and
exhausted the stack (SIGSEGV at parse time). jinja2 guards recursion here.
Guard integer division and modulo against a zero divisor at all sites (the
BinaryOpExpr evaluation switch and the Value operators). Previously {{ 1/0 }},
{{ 5//0 }} or {{ x%0 }} crashed with SIGFPE at render time.
Both throw std::runtime_error, consistent with existing error handling. Verified
against 239 real chat templates (unchanged) and normal arithmetic
(1+2*3=7, 10%3=1, 8/2=4). Found via coverage-guided fuzzing.
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Add a recursion depth cap in Parser::parseExpression. Deeply-nested expressions
previously recursed through the expression-precedence chain without bound and
exhausted the stack (SIGSEGV at parse time). jinja2 guards recursion here.
Guard integer division and modulo against a zero divisor at all sites (the
BinaryOpExpr evaluation switch and the Value operators). Previously {{ 1/0 }},
{{ 5//0 }} or {{ x%0 }} crashed with SIGFPE at render time.
Both throw std::runtime_error, consistent with existing error handling. Verified
against 239 real chat templates (unchanged) and normal arithmetic
(1+2*3=7, 10%3=1, 8/2=4). Found via coverage-guided fuzzing."