diff options
| author |   Alex Elder <elder@linaro.org> | 2023-03-28 11:27:51 -0500 |
|---|---|---|
| committer |   Jakub Kicinski <kuba@kernel.org> | 2023-03-29 21:27:40 -0700 |
| commit | 6c75dc94f2b27fff57b305af9236eea181a00b6c (patch) | |
| tree | 918bcbe45126d252383daf7c7b755ba3c29946ab /drivers/net/ipa | |
| parent | net: wwan: iosm: fixes 7560 modem crash (diff) | |
| download | wireguard-linux-6c75dc94f2b27fff57b305af9236eea181a00b6c.tar.xz wireguard-linux-6c75dc94f2b27fff57b305af9236eea181a00b6c.zip | |
net: ipa: compute DMA pool size properly
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: 9dd441e4ed57 ("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>
Diffstat (limited to 'drivers/net/ipa')
| -rw-r--r-- | drivers/net/ipa/gsi_trans.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/ipa/gsi_trans.c b/drivers/net/ipa/gsi_trans.c index 0f52c068c46d..ee6fb00b71eb 100644 --- a/drivers/net/ipa/gsi_trans.c +++ b/drivers/net/ipa/gsi_trans.c @@ -156,7 +156,7 @@ int gsi_trans_pool_init_dma(struct device *dev, struct gsi_trans_pool *pool, * gsi_trans_pool_exit_dma() can assume the total allocated * size is exactly (count * size). */ - total_size = get_order(total_size) << PAGE_SHIFT; + total_size = PAGE_SIZE << get_order(total_size); virt = dma_alloc_coherent(dev, total_size, &addr, GFP_KERNEL); if (!virt) |