From: Qiang Yu <quic_qianyu@quicinc.com> stable inclusion from stable-v5.10.209 commit 20a6dea2d1c68d4e03c6bb50bc12e72e226b5c0e category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I97NHA CVE: CVE-2023-52493 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- Ensure read and write locks for the channel are not taken in succession by dropping the read lock from parse_xfer_event() such that a callback given to client can potentially queue buffers and acquire the write lock in that process. Any queueing of buffers should be done without channel read lock acquired as it can result in multiple locks and a soft lockup. Cc: <stable@vger.kernel.org> # 5.7 Fixes: 1d3173a3bae7 ("bus: mhi: core: Add support for processing events from client device") Signed-off-by: Qiang Yu <quic_qianyu@quicinc.com> Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com> Tested-by: Jeffrey Hugo <quic_jhugo@quicinc.com> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Link: https://lore.kernel.org/r/1702276972-41296-3-git-send-email-quic_qianyu@quic... [mani: added fixes tag and cc'ed stable] Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Guan Jing <guanjing6@huawei.com> --- drivers/bus/mhi/host/main.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c index 82d6e9e8bddf..b0a83a725069 100644 --- a/drivers/bus/mhi/host/main.c +++ b/drivers/bus/mhi/host/main.c @@ -570,6 +570,8 @@ static int parse_xfer_event(struct mhi_controller *mhi_cntrl, mhi_del_ring_element(mhi_cntrl, tre_ring); local_rp = tre_ring->rp; + read_unlock_bh(&mhi_chan->lock); + /* notify client */ mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result); @@ -592,6 +594,8 @@ static int parse_xfer_event(struct mhi_controller *mhi_cntrl, kfree(buf_info->cb_buf); } } + + read_lock_bh(&mhi_chan->lock); } break; } /* CC_EOT */ -- 2.34.1