Fix buffer overflow in argument parsing caused by lexer returning length beyond length of string #979
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Signed-off-by: Shane Loretz <sloretz@openrobotics.org>
Signed-off-by: Shane Loretz <sloretz@openrobotics.org>
Signed-off-by: Shane Loretz <sloretz@openrobotics.org>
Signed-off-by: Shane Loretz <sloretz@openrobotics.org>
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ivanpauno
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…gth beyond length of string (#979) * Test that lexer never returns length longer than string Signed-off-by: Shane Loretz <sloretz@openrobotics.org> * Fix bug where lexer returned length longer than string Signed-off-by: Shane Loretz <sloretz@openrobotics.org> * Test that peeking 2 ahead never goes beyond NONE or EOF Signed-off-by: Shane Loretz <sloretz@openrobotics.org> * Stop peeking if the first lexeme is NONE or EOF Signed-off-by: Shane Loretz <sloretz@openrobotics.org> (cherry picked from commit 392f0d3)
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…gth beyond length of string (#979) * Test that lexer never returns length longer than string Signed-off-by: Shane Loretz <sloretz@openrobotics.org> * Fix bug where lexer returned length longer than string Signed-off-by: Shane Loretz <sloretz@openrobotics.org> * Test that peeking 2 ahead never goes beyond NONE or EOF Signed-off-by: Shane Loretz <sloretz@openrobotics.org> * Stop peeking if the first lexeme is NONE or EOF Signed-off-by: Shane Loretz <sloretz@openrobotics.org> (cherry picked from commit 392f0d3)
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…gth beyond length of string (#979) (#980) * Test that lexer never returns length longer than string Signed-off-by: Shane Loretz <sloretz@openrobotics.org> * Fix bug where lexer returned length longer than string Signed-off-by: Shane Loretz <sloretz@openrobotics.org> * Test that peeking 2 ahead never goes beyond NONE or EOF Signed-off-by: Shane Loretz <sloretz@openrobotics.org> * Stop peeking if the first lexeme is NONE or EOF Signed-off-by: Shane Loretz <sloretz@openrobotics.org> (cherry picked from commit 392f0d3) Co-authored-by: Shane Loretz <sloretz@openrobotics.org>
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…gth beyond length of string (#979) (#981) * Test that lexer never returns length longer than string Signed-off-by: Shane Loretz <sloretz@openrobotics.org> * Fix bug where lexer returned length longer than string Signed-off-by: Shane Loretz <sloretz@openrobotics.org> * Test that peeking 2 ahead never goes beyond NONE or EOF Signed-off-by: Shane Loretz <sloretz@openrobotics.org> * Stop peeking if the first lexeme is NONE or EOF Signed-off-by: Shane Loretz <sloretz@openrobotics.org> (cherry picked from commit 392f0d3) Co-authored-by: Shane Loretz <sloretz@openrobotics.org>
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While running
rcl's tests under address sanitizer I noticed a buffer overflow in test_arguments here:rcl/rcl/test/rcl/test_arguments.cpp
Line 239 in 71baed4
Address sanitizer output in test
The lexer tries to match the lexeme TILDE_SLASH, but fails because the end of the string is reached. When matching a lexeme fails, the lexer uses a default transition to T_NONE. This transition increases the length of the lexeme by 1, with the idea being to make the length include the character which caused no lexeme to be found so it can be included in error messages. This behavior is a problem when the end of the string is reached, because any code trying to access the problematic string now reads 1 past the end of the string.
In this particular case,
rcl_lexer_lookahead2_peek2()caused the overflow by trying to read a second lexeme starting at one past the end of the string.This PR fixes the buffer overflow in two ways. First it makes sure the lexer never returns a length beyond the length of the string. Second, it makes
rcl_lexer_lookahead2_peek2()stop peeking at the string if the first peek is NONE or EOF.