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| author | Jeffrey Hugo <quic_jhugo@quicinc.com> | 2025-03-06 20:29:13 +0300 |
|---|---|---|
| committer | Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> | 2025-03-14 08:57:15 +0300 |
| commit | 0686a818d77a431fc3ba2fab4b46bbb04e8c9380 (patch) | |
| tree | 160c172634556f63265bd73cef8d2c4c71c1aafa | |
| parent | cba6bdfd79291b82422b6e6b4036ebc076d5625f (diff) | |
| download | linux-0686a818d77a431fc3ba2fab4b46bbb04e8c9380.tar.xz | |
bus: mhi: host: Fix race between unprepare and queue_buf
A client driver may use mhi_unprepare_from_transfer() to quiesce
incoming data during the client driver's tear down. The client driver
might also be processing data at the same time, resulting in a call to
mhi_queue_buf() which will invoke mhi_gen_tre(). If mhi_gen_tre() runs
after mhi_unprepare_from_transfer() has torn down the channel, a panic
will occur due to an invalid dereference leading to a page fault.
This occurs because mhi_gen_tre() does not verify the channel state
after locking it. Fix this by having mhi_gen_tre() confirm the channel
state is valid, or return error to avoid accessing deinitialized data.
Cc: stable@vger.kernel.org # 6.8
Fixes: b89b6a863dd5 ("bus: mhi: host: Add spinlock to protect WP access when queueing TREs")
Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Jeff Hugo <jeff.hugo@oss.qualcomm.com>
Reviewed-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Reviewed-by: Youssef Samir <quic_yabdulra@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Troy Hanson <quic_thanson@quicinc.com>
Link: https://lore.kernel.org/r/20250306172913.856982-1-jeff.hugo@oss.qualcomm.com
[mani: added stable tag]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
| -rw-r--r-- | drivers/bus/mhi/host/main.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c index 4c91ffd6ed0e..9bb0df43ceef 100644 --- a/drivers/bus/mhi/host/main.c +++ b/drivers/bus/mhi/host/main.c @@ -1188,11 +1188,16 @@ int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan, struct mhi_ring_element *mhi_tre; struct mhi_buf_info *buf_info; int eot, eob, chain, bei; - int ret; + int ret = 0; /* Protect accesses for reading and incrementing WP */ write_lock_bh(&mhi_chan->lock); + if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED) { + ret = -ENODEV; + goto out; + } + buf_ring = &mhi_chan->buf_ring; tre_ring = &mhi_chan->tre_ring; @@ -1210,10 +1215,8 @@ int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan, if (!info->pre_mapped) { ret = mhi_cntrl->map_single(mhi_cntrl, buf_info); - if (ret) { - write_unlock_bh(&mhi_chan->lock); - return ret; - } + if (ret) + goto out; } eob = !!(flags & MHI_EOB); @@ -1231,9 +1234,10 @@ int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan, mhi_add_ring_element(mhi_cntrl, tre_ring); mhi_add_ring_element(mhi_cntrl, buf_ring); +out: write_unlock_bh(&mhi_chan->lock); - return 0; + return ret; } int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir, |