Messages in this thread | | | From | Zekun Shen <> | Date | Sat, 4 Jul 2020 12:37:04 -0400 | Subject | Re: [PATCH] net: fm10k: check size from dma region |
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On Sat, Jul 04, 2020 at 09:05:48AM -0700, Alexander Duyck wrote: > The upper limitation for the size should be 2K or FM10K_RX_BUFSZ, not > PAGE_SIZE. Otherwise you are still capable of going out of bounds > because the offset is used within the page to push the start of the > region up by 2K. PAGE_SIZE can drop the warning, as the dma allocated size is PAGE_SIZE.
> If this is actually fixing the warning it makes me wonder if the code > performing the check is broken itself since we would still be > accessing outside of the accessible DMA range. The unbounded size is only passed to fm10k_add_rx_frag, which expects and checks size to be less than FM10K_RX_HDR_LEN which is 256.
In this way, any boundary between 256 and 4K should work. I could address that with a second version.
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