In ca8210_spi_transfer(), each SPI transfer reads sizeof(struct mac_message) bytes into cas_ctl->tx_in_buf: cas_ctl->transfer.len = sizeof(struct mac_message); However, ca8210_rx_done() only checks the received packet length len = buf[1] + 2 against CA8210_SPI_BUF_SIZE (256). When buf[0] & SPI_SYN is set and priv->sync_command_response is non-NULL, memcpy() copies up to 256 bytes into priv->sync_command_response, which points to a struct mac_message object on the synchronous caller's stack, overflowing the stack buffer: BUG: KASAN: stack-out-of-bounds in ca8210_rx_done+0x117/0x6c0 Write of size 256 at addr ffff8881009e7c40 by task swapper/0/1 Call Trace: dump_stack_lvl+0x70/0xa0 print_report+0x153/0x4c6 kasan_report+0xf1/0x120 kasan_check_range+0x125/0x200 __asan_memcpy+0x3c/0x60 ca8210_rx_done+0x117/0x6c0 ... This frame has 1 object: [32, 182) 'response' Check len > sizeof(struct mac_message) instead of len > CA8210_SPI_BUF_SIZE in ca8210_rx_done() so that any packet exceeding sizeof(struct mac_message) is logged as erroneously long via dev_crit() and dropped before copying into priv->sync_command_response or passing it to ca8210_net_rx(). Tested in QEMU with KASAN enabled by passing a 256-byte SPI_SYN response into ca8210_rx_done(). Fixes: ded845a781a5 ("ieee802154: Add CA8210 IEEE 802.15.4 device driver") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Hui Peng --- Changes in v3: - Check len > sizeof(struct mac_message) at the top of ca8210_rx_done() where dev_crit() logs the error and drops the packet instead of silently truncating memcpy() with min_t(), addressing David Laight's feedback. Changes in v2: - Split the ca8210 fixes into three single-issue patches (1/3..3/3). drivers/net/ieee802154/ca8210.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ieee802154/ca8210.c b/drivers/net/ieee802154/ca8210.c index 01af4f9..a990a0f 100644 --- a/drivers/net/ieee802154/ca8210.c +++ b/drivers/net/ieee802154/ca8210.c @@ -686,7 +686,7 @@ static void ca8210_rx_done(struct cas_control *cas_ctl) buf = cas_ctl->tx_in_buf; len = buf[1] + 2; - if (len > CA8210_SPI_BUF_SIZE) { + if (len > sizeof(struct mac_message)) { dev_crit( &priv->spi->dev, "Received packet len (%u) erroneously long\n", -- 2.49.0