Thomas Zimmermann f0adbc382b drm/ast: Allocate initial CRTC state of the correct size ... The ast driver inherits from DRM's CRTC state, but still uses the atomic helper for struct drm_crtc_funcs.reset, drm_atomic_helper_crtc_reset(). The helper only allocates enough memory for the core CRTC state. That results in an out-ouf-bounds access when duplicating the initial CRTC state. Simplified backtrace shown below: [ 21.469321] ================================================================== [ 21.469434] BUG: KASAN: slab-out-of-bounds in ast_crtc_atomic_duplicate_state+0x84/0x100 [ast] [ 21.469445] Read of size 8 at addr ffff888036c1c5f8 by task systemd-udevd/382 [ 21.469451] [ 21.469464] CPU: 2 PID: 382 Comm: systemd-udevd Tainted: G E 5.5.0-rc6-1-default+ #214 [ 21.469473] Hardware name: Sun Microsystems SUN FIRE X2270 M2/SUN FIRE X2270 M2, BIOS 2.05 07/01/2010 [ 21.469480] Call Trace: [ 21.469501] dump_stack+0xb8/0x110 [ 21.469528] print_address_description.constprop.0+0x1b/0x1e0 [ 21.469557] ? ast_crtc_atomic_duplicate_state+0x84/0x100 [ast] [ 21.469581] ? ast_crtc_atomic_duplicate_state+0x84/0x100 [ast] [ 21.469597] __kasan_report.cold+0x1a/0x35 [ 21.469640] ? ast_crtc_atomic_duplicate_state+0x84/0x100 [ast] [ 21.469665] kasan_report+0xe/0x20 [ 21.469693] ast_crtc_atomic_duplicate_state+0x84/0x100 [ast] [ 21.469733] drm_atomic_get_crtc_state+0xbf/0x1c0 [ 21.469768] __drm_atomic_helper_set_config+0x81/0x5a0 [ 21.469803] ? drm_atomic_plane_check+0x690/0x690 [ 21.469843] ? drm_client_rotation+0xae/0x240 [ 21.469876] drm_client_modeset_commit_atomic+0x230/0x390 [ 21.469888] ? __mutex_lock+0x8f0/0xbe0 [ 21.469929] ? drm_client_firmware_config.isra.0+0xa60/0xa60 [ 21.469948] ? drm_client_modeset_commit_force+0x28/0x230 [ 21.470031] ? memset+0x20/0x40 [ 21.470078] drm_client_modeset_commit_force+0x90/0x230 [ 21.470110] drm_fb_helper_restore_fbdev_mode_unlocked+0x5f/0xc0 [ 21.470132] drm_fb_helper_set_par+0x59/0x70 [ 21.470155] fbcon_init+0x61d/0xad0 [ 21.470185] ? drm_fb_helper_restore_fbdev_mode_unlocked+0xc0/0xc0 [ 21.470232] visual_init+0x187/0x240 [ 21.470266] do_bind_con_driver+0x2e3/0x460 [ 21.470321] do_take_over_console+0x20a/0x290 [ 21.470371] do_fbcon_takeover+0x85/0x100 [ 21.470402] register_framebuffer+0x2fd/0x490 [ 21.470425] ? kzalloc.constprop.0+0x10/0x10 [ 21.470503] __drm_fb_helper_initial_config_and_unlock+0xf2/0x140 [ 21.470533] drm_fbdev_client_hotplug+0x162/0x250 [ 21.470563] drm_fbdev_generic_setup+0xd2/0x155 [ 21.470602] ast_driver_load+0x688/0x850 [ast] <...> [ 21.472625] ================================================================== Allocating enough memory for struct ast_crtc_state in a custom ast CRTC reset handler fixes the problem. v2: * implement according to drm_atomic_helper_crtc_reset() * update state with __drm_atomic_helper_crtc_reset() Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Fixes: 83be6a3ceb ("drm/ast: Introduce struct ast_crtc_state") Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Gerd Hoffmann <kraxel@redhat.com> Cc: Dave Airlie <airlied@redhat.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: "Noralf Trønnes" <noralf@tronnes.org> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200130094012.32140-1-tzimmermann@suse.de		2020-04-20 15:48:23 +02:00
..
ast_dp501.c	drm/ast: drop use of drmP.h	2019-07-15 18:11:31 +02:00
ast_dram_tables.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
ast_drv.c	drm/ast: Set up fbdev after registering device; remove error checks	2020-04-08 16:24:23 +02:00
ast_drv.h	drm/ast: Use simple encoder	2020-03-02 09:22:43 +01:00
ast_main.c	drm/ast: Set up fbdev after registering device; remove error checks	2020-04-08 16:24:23 +02:00
ast_mode.c	drm/ast: Allocate initial CRTC state of the correct size	2020-04-20 15:48:23 +02:00
ast_post.c	drm main pull for 5.4-rc1	2019-09-19 16:24:24 -07:00
ast_tables.h	drm/ast: Fixed 1280x800 Display Issue	2018-03-23 09:50:54 +10:00
ast_ttm.c	drm/vram: Have VRAM MM call GEM VRAM functions directly	2019-09-12 19:54:42 +02:00
Kconfig	drm/vram: fix Kconfig	2019-09-10 08:53:08 +02:00
Makefile	drm/ast: Replace struct ast_fbdev with generic framebuffer emulation	2019-07-09 10:25:12 +02:00