Fix buffer overflow in mono #123168
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Fix buffer overflow in mono #123168
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If under certain conditions op can take the value OP_LAST, an overflow will occur because the opidx array contains OP_LAST - OP_LOAD elements.
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Thanks a lot - looks good to me.
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@tpa95 Did this ever happen in practice somewhere ? It would be asserting now, so that would need to be fixed as well. |
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@BrzVlad No, I didn’t observe it in practice; it was reported by static analysis (Svace) as a buffer overflow issue. OP_LAST is a sentinel and not a valid opcode to be passed to mono_inst_name(). Now, if op == OP_LAST we can index opidx out of bounds (op - OP_LOAD), which is UB. Changing the condition to op < OP_LAST avoids the buffer overflow. |
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Tagging subscribers to this area: @steveisok, @vitek-karas |
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If under certain conditions op can take the value OP_LAST, an overflow will occur because the opidx array contains OP_LAST - OP_LOAD elements.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Reporter: Pavel Tikhomirov ([email protected]).
Organization: Gazinformservice ([email protected]).