From dc5ca34f5e8dc10c566ef39aa3b1a201a17ca734 Mon Sep 17 00:00:00 2001 From: Pufan Jin Date: Fri, 16 Oct 2026 21:08:12 +0800 Subject: [PATCH] spi: zynq-qspi: fix address buffer corruption and support 4-byte address In zynq_qspi_exec_mem_op(), when transmitting address bytes, the driver iterates over op->addr.nbytes and populates xqspi->txbuf[i]. However, xqspi->txbuf is never re-assigned before populating the address, meaning it still points to (u8 *)&op->cmd.opcode from the command phase. This causes two severe issues: 1. Memory corruption: Writing into xqspi->txbuf writes past the opcode buffer on the stack (which was passed as const struct spi_mem_op *). If opcode is zero, xqspi->txbuf is uninitialized. 2. In zynq_qspi_supports_op(), operations with op->addr.nbytes > 3 are rejected. When paired with SPI NOR flashes larger than 16MB (such as Winbond W25Q256), spi_nor_spimem_check_read_pp_op() tests 4-byte address support, which fails and causes spi_nor_select_read() to drop all read capabilities, failing probe with -EINVAL (-22). The Zynq-7000 QSPI controller hardware in manual I/O mode natively supports transmitting 1 to 4 address bytes via its TXD FIFO registers (ZYNQ_QSPI_TXD_00_00_OFFSET). Fix this by introducing a local opaddr[4] buffer in zynq_qspi_exec_mem_op() and explicitly setting xqspi->txbuf = opaddr before populating address bytes. Also allow up to 4 address bytes in zynq_qspi_supports_op(). Fixes: 67dca5e580f1 ("spi: spi-mem: Add support for Zynq QSPI controller") Cc: stable@vger.kernel.org Signed-off-by: Pufan Jin Link: https://patch.msgid.link/20261016130812.282624-1-cyan2254650260@gmail.com Signed-off-by: Mark Brown --- drivers/spi/spi-zynq-qspi.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/spi/spi-zynq-qspi.c b/drivers/spi/spi-zynq-qspi.c index d762aaf452af..bfcbcfe85b91 100644 --- a/drivers/spi/spi-zynq-qspi.c +++ b/drivers/spi/spi-zynq-qspi.c @@ -229,11 +229,10 @@ static bool zynq_qspi_supports_op(struct spi_mem *mem, return false; /* - * The number of address bytes should be equal to or less than 3 bytes. + * The number of address bytes should be equal to or less than 4 bytes. */ - if (op->addr.nbytes > 3) + if (op->addr.nbytes > 4) return false; - return true; } @@ -526,6 +525,7 @@ static int zynq_qspi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op) { struct zynq_qspi *xqspi = spi_controller_get_devdata(mem->spi->controller); + u8 opaddr[4] __aligned(4); int err = 0, i; u8 *tmpbuf; @@ -547,12 +547,13 @@ static int zynq_qspi_exec_mem_op(struct spi_mem *mem, } if (op->addr.nbytes) { - for (i = 0; i < op->addr.nbytes; i++) { - xqspi->txbuf[i] = op->addr.val >> + for (i = 0; i < op->addr.nbytes; i++) + opaddr[i] = op->addr.val >> (8 * (op->addr.nbytes - i - 1)); - } reinit_completion(&xqspi->data_completion); + xqspi->txbuf = opaddr; + xqspi->rxbuf = NULL; xqspi->tx_bytes = op->addr.nbytes; xqspi->rx_bytes = op->addr.nbytes;