From 50dec95c9d1f1f82819bc898ef2b60fa83fd4ccd Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Mon, 13 Jul 2026 16:05:36 +0300 Subject: [PATCH] i3c: renesas: Fix out-of-bounds access for newdevs mask When software initiates DAA (Dynamic Address Assignment), the controller reports the result via the NRSPQP (Normal Response Queue Port Register). The data length field of the response descriptor, which is accessible through the NRSPQP register, indicates the number of devices remaining after DAA. Consequently, when the bus is empty, this field contains the maximum number of devices supported by the controller (8 for the Renesas I3C controller). Adjust the condition that computes the newly discovered devices bitmask to prevent an out-of-bounds when the I3C bus is empty. Fixes: e7218986319b ("i3c: renesas: Add suspend/resume support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea Reviewed-by: Frank Li Tested-by: Tommaso Merciai Link: https://patch.msgid.link/20260713130545.568657-9-claudiu.beznea+renesas@tuxon.dev Signed-off-by: Alexandre Belloni --- drivers/i3c/master/renesas-i3c.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/i3c/master/renesas-i3c.c b/drivers/i3c/master/renesas-i3c.c index 216c8b969ec8..6518a18e019b 100644 --- a/drivers/i3c/master/renesas-i3c.c +++ b/drivers/i3c/master/renesas-i3c.c @@ -703,7 +703,11 @@ static int renesas_i3c_daa(struct i3c_master_controller *m) renesas_i3c_wait_xfer(i3c, xfer); - newdevs = GENMASK(i3c->maxdevs - cmd->rx_count - 1, 0); + if (cmd->rx_count >= i3c->maxdevs) + newdevs = 0; + else + newdevs = GENMASK(i3c->maxdevs - cmd->rx_count - 1, 0); + newdevs &= ~olddevs; for (pos = 0; pos < i3c->maxdevs; pos++) {