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authorZhou Qingyang <zhou1615@umn.edu>2022-01-24 19:57:29 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-04-15 15:14:47 +0300
commit2c729dec8c1e3e2892fde5ce8181553860914e74 (patch)
tree24dcbe4e1318e3252907585bf8761443e8094b7e
parent1b1c5a6f433b989decf6b7593ef1c81193b31886 (diff)
downloadlinux-2c729dec8c1e3e2892fde5ce8181553860914e74.tar.xz
drm/amd/display: Fix a NULL pointer dereference in amdgpu_dm_connector_add_common_modes()
[ Upstream commit 588a70177df3b1777484267584ef38ab2ca899a2 ] In amdgpu_dm_connector_add_common_modes(), amdgpu_dm_create_common_mode() is assigned to mode and is passed to drm_mode_probed_add() directly after that. drm_mode_probed_add() passes &mode->head to list_add_tail(), and there is a dereference of it in list_add_tail() without recoveries, which could lead to NULL pointer dereference on failure of amdgpu_dm_create_common_mode(). Fix this by adding a NULL check of mode. This bug was found by a static analyzer. Builds with 'make allyesconfig' show no new warnings, and our static analyzer no longer warns about this code. Fixes: e7b07ceef2a6 ("drm/amd/display: Merge amdgpu_dm_types and amdgpu_dm") Signed-off-by: Zhou Qingyang <zhou1615@umn.edu> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index ed02bb6b2cd0..b2835cd41d3e 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3593,6 +3593,9 @@ static void amdgpu_dm_connector_add_common_modes(struct drm_encoder *encoder,
mode = amdgpu_dm_create_common_mode(encoder,
common_modes[i].name, common_modes[i].w,
common_modes[i].h);
+ if (!mode)
+ continue;
+
drm_mode_probed_add(connector, mode);
amdgpu_dm_connector->num_modes++;
}