net sched actions: allocate act cookie early
Policing filters do not use the TCA_ACT_* enum and the tb[] nlattr array in tcf_action_init_1() doesn't get filled for them so we should not try to look for a TCA_ACT_COOKIE attribute in the then uninitialized array. The error handling in cookie allocation then calls tcf_hash_release() leading to invalid memory access later on. Additionally, if cookie allocation fails after an already existing non-policing filter has successfully been changed, tcf_action_release() should not be called, also we would have to roll back the changes in the error handling, so instead we now allocate the cookie early and assign it on success at the end. CVE-2017-7979 Fixes: 1045ba77 ("net sched actions: Add support for user cookies") Signed-off-by:Wolfgang Bumiller <w.bumiller@proxmox.com> Acked-by:
Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
parent
43af3905
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