Messages in this thread | | | From | Andreas Schwab <> | Subject | Re: Possible array overrun in lzma_reset() | Date | Sat, 22 Jan 2011 23:22:08 +0100 |
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Jesper Juhl <jj@chaosbits.net> writes:
> 787 probs = s->lzma.is_match[0]; > At conditional (1): "i < 14134UL" taking true path > At conditional (2): "i < 14134UL" taking true path > At conditional (3): "i < 14134UL" taking true path > 788 for (i = 0; i < PROBS_TOTAL; ++i) > Event overrun-local: Overrunning static array of size 32 bytes at byte position 28266 by indexing pointer "probs" with index variable "i". > Event overrun-local: Note: These bugs are often difficult to see at first glance. Coverity recommends a close inspection of the events leading to this overrun. > 789 probs[i] = RC_BIT_MODEL_TOTAL / 2; > ... > > I looked into the report and found that 's->lzma.is_match' is > uint16_t is_match[STATES][POS_STATES_MAX] > where 'STATES' is '#define STATES 12' and 'POS_STATES_MAX' is '#define POS_STATES_MAX (1 << 4)'. > > So I think the checker has a point.
The loop treats the part of the structure from is_match to the end as a single array of PROBS_TOTAL uint16_t (which it is, in effect).
Andreas.
-- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."
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