From 3fdd8f3a94cc7437c1c7ab9d8c82ea7c3148114c Mon Sep 17 00:00:00 2001 From: Aleksandr Mishin Date: Mon, 8 Apr 2024 15:58:10 +0300 Subject: [PATCH] drm: bridge: cdns-mhdp8546: Fix possible null pointer dereference [ Upstream commit 935a92a1c400285545198ca2800a4c6c519c650a ] In cdns_mhdp_atomic_enable(), the return value of drm_mode_duplicate() is assigned to mhdp_state->current_mode, and there is a dereference of it in drm_mode_set_name(), which will lead to a NULL pointer dereference on failure of drm_mode_duplicate(). Fix this bug add a check of mhdp_state->current_mode. Fixes: fb43aa0acdfd ("drm: bridge: Add support for Cadence MHDP8546 DPI/DP bridge") Signed-off-by: Aleksandr Mishin Reviewed-by: Robert Foss Signed-off-by: Robert Foss Link: https://patchwork.freedesktop.org/patch/msgid/20240408125810.21899-1-amishin@t-argos.ru Signed-off-by: Sasha Levin --- drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index f56ff97c9..ae99d04f0 100755 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c @@ -1978,6 +1978,9 @@ static void cdns_mhdp_atomic_enable(struct drm_bridge *bridge, mhdp_state = to_cdns_mhdp_bridge_state(new_state); mhdp_state->current_mode = drm_mode_duplicate(bridge->dev, mode); + if (!mhdp_state->current_mode) + return; + drm_mode_set_name(mhdp_state->current_mode); dev_dbg(mhdp->dev, "%s: Enabling mode %s\n", __func__, mode->name);