Messages in this thread | | | Subject | Re: [PATCH] bpf: devmap: Check attr->max_entries more carefully | From | John Fastabend <> | Date | Mon, 16 Oct 2017 21:30:38 -0700 |
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On 10/15/2017 03:13 PM, Richard Weinberger wrote: > Am Montag, 16. Oktober 2017, 00:00:20 CEST schrieb Richard Weinberger: >> max_entries is user controlled and used as input for __alloc_percpu(). >> This function expects that the allocation size is a power of two and >> less than PCPU_MIN_UNIT_SIZE. >> Otherwise a WARN() is triggered. > > On a second though, I think we should also have a hard limit for ->max_entries > or check for an overflow here: >
Or just,
static u64 dev_map_bitmap_size(const union bpf_attr *attr) { return BITS_TO_LONGS((u64) attr->max_entries) * sizeof(unsigned long); }
Let me know if you want me to send a patch or if you want to.
Thanks, John
> static u64 dev_map_bitmap_size(const union bpf_attr *attr) > { > return BITS_TO_LONGS(attr->max_entries) * sizeof(unsigned long); > } > > Thanks, > //richard >
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