When a caller is not interested in the returned message, the ret_payload pointer is set to NULL in the u-boot-sources. In this case, under EL3, the memory from address 0x0 would be overwritten by ipi_req() with the returned IPI message, damaging the original data under this address. The patch, in case ret_payload is NULL, assigns the pointer to the array holding the IPI message being sent.
Signed-off-by: Adrian Fiergolski <adrian.fiergol...@fastree3d.com> Signed-off-by: Michal Simek <michal.si...@xilinx.com> --- Based on origin series from Adrian. That's why also adding his SoB line. https://lore.kernel.org/r/20211014124349.1429696-1-adrian.fiergol...@fastree3d.com Adrian: The patch is just suggestion how we could avoid that NULL pointer writes but done in ipi_req() --- drivers/firmware/firmware-zynqmp.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/firmware/firmware-zynqmp.c b/drivers/firmware/firmware-zynqmp.c index 1391aab0a160..7e498d8169e8 100644 --- a/drivers/firmware/firmware-zynqmp.c +++ b/drivers/firmware/firmware-zynqmp.c @@ -30,6 +30,10 @@ static int ipi_req(const u32 *req, size_t req_len, u32 *res, size_t res_maxlen) { struct zynqmp_ipi_msg msg; int ret; + u32 buffer[PAYLOAD_ARG_CNT]; + + if (!res) + res = buffer; if (req_len > PMUFW_PAYLOAD_ARG_CNT || res_maxlen > PMUFW_PAYLOAD_ARG_CNT) -- 2.33.1
