net: ipa: compute DMA pool size properly
[ Upstream commit 6c75dc94 ] In gsi_trans_pool_init_dma(), the total size of a pool of memory used for DMA transactions is calculated. However the calculation is done incorrectly. For 4KB pages, this total size is currently always more than one page, and as a result, the calculation produces a positive (though incorrect) total size. The code still works in this case; we just end up with fewer DMA pool entries than we intended. Bjorn Andersson tested booting a kernel with 16KB pages, and hit a null pointer derereference in sg_alloc_append_table_from_pages(), descending from gsi_trans_pool_init_dma(). The cause of this was that a 16KB total size was going to be allocated, and with 16KB pages the order of that allocation is 0. The total_size calculation yielded 0, which eventually led to the crash. Correcting the total_size calculation fixes the problem. Reported-by:Bjorn Andersson <quic_bjorande@quicinc.com> Tested-by:
Bjorn Andersson <quic_bjorande@quicinc.com> Fixes: 9dd441e4 ("soc: qcom: ipa: GSI transactions") Reviewed-by:
Mark Bloch <mbloch@nvidia.com> Signed-off-by:
Alex Elder <elder@linaro.org> Reviewed-by:
Leon Romanovsky <leonro@nvidia.com> Link: https://lore.kernel.org/r/20230328162751.2861791-1-elder@linaro.org Signed-off-by:
Jakub Kicinski <kuba@kernel.org> Signed-off-by:
Sasha Levin <sashal@kernel.org>
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