pkg/report: double-free is at least as severe as UAF write #6691
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Collaborator
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Note that we don't use merge commits here, we rebase. The checks will now fail. |
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This documentation reflects https://github.com/google/syzkaller/blob/master/pkg/report/impact_score.go . |
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Please also change logic in pkg/report/impact_score.go, that's what actually matters and affects syzbot presentation. |
Double-free is at least as severe as a UAF write because in case of UAF write, the vulnerable object is given and you have to find the right victim object - the writable offset and size needs to match. In case of double-free you can choose both your victim and attacker object, giving more options for a successful exploitation (there are attacker objects which can basically write all offset and sizes). This assumes that double-free is controlled in a way that the attacker can spray a victim object between the two `kfree()`s.
tarasmadan
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Jan 26, 2026
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Double-free is at least as severe as a UAF write because in case of UAF write, the vulnerable object is given and you have to find the right victim object - the writable offset and size needs to match.
In case of double-free you can choose both your victim and attacker object, giving more options for a successful exploitation (there are attacker objects which can basically write all offset and sizes).
This assumes that double-free is controlled in a way that the attacker can spray a victim object between the two
kfree()s.