Bug 2545406

Kernels since kernel-7.3.0-0.rc5.45.fc46 are failing openQA tests. The problem seems to be that tests fail when switching VT and attempting to log in.

I can reproduce this in a local VM. Install Rawhide, update to current, install the current gated kernel update - https://bodhi.fedoraproject.org/updates/FEDORA-2026-acf69ef47b - and reboot. VT 1 appears not to be using kmscon - you can log in on it successfully, but it's using old school fonts, indicating it's not kmscon. Switch to VT 6 (ctrl-alt-f6), again you see old-school fonts. If you try to log in here, it fails, it cycles back to the login prompt.

After doing this, coredumpctl shows three kmscon crashes. Here is the backtrace of the most recent one:


Thread 1 (Thread 0x7f4ba962a8c0 (LWP 865)):
#0  get_property_value (fd=fd@entry=16, props=props@entry=0x0, name=0x55fe521b3818 "type") at ../src/video/drm_shared.c:83
        prop = <optimized out>
        value = <optimized out>
        j = 0
#1  0x000055fe521dad32 in modeset_find_plane (fd=16, disp=0x55fe5ec6d230) at ../src/video/drm_shared.c:258
        props = 0x0
        plane_id = 36
        plane_type = <optimized out>
        plane = 0x55fe5ec587a0
        ddrm = <optimized out>
        plane_res = 0x55fe5ec58b20
        found_primary = true
        found_cursor = false
        i = 1
        ret = <optimized out>
#2  bind_display (video=0x55fe5ec585c0, res=<optimized out>, conn=<optimized out>) at ../src/video/drm_shared.c:1416
        vdrm = 0x55fe5ec58450
        disp = 0x55fe5ec6d230
        ddrm = <optimized out>
        name = <optimized out>
        ret = 0
        err_unref = <optimized out>
#3  drm_video_hotplug (video=0x55fe5ec585c0, read_dpms=read_dpms@entry=true, modeset=modeset@entry=true) at ../src/video/drm_shared.c:1509
        found = false
        __ptr = <optimized out>
        vdrm = <optimized out>
        res = <optimized out>
        conn = <optimized out>
        disp = <optimized out>
        ddrm = <optimized out>
        ret = <optimized out>
        i = <optimized out>
        dpms = <optimized out>
        tmp = <optimized out>
        needs_modeset = true
#4  0x000055fe521db490 in drm_video_wake_up (video=video@entry=0x55fe5ec585c0) at ../src/video/drm_shared.c:1552
        ret = <optimized out>
        vdrm = 0x55fe5ec58450
#5  0x000055fe521df094 in drm2d_video_wake_up (video=0x55fe5ec585c0) at ../src/video/drm2d_video.c:317
        ret = <optimized out>
#6  0x000055fe521d55b3 in video_wake_up (video=0x55fe5ec585c0) at ../src/video/video.c:573
        ret = <optimized out>
#7  video_wake_up (video=0x55fe5ec585c0) at ../src/video/video.c:561
        ret = 0
#8  0x000055fe521cc0a9 in seat_video_init (vid=vid@entry=0x55fe5ec57e60) at ../src/seat.c:948
        seat = 0x55fe5eb1e6e0
        width = 0
        height = 0
        backend = 0x55fe521b82da <be_drm2d> "drm2d"
        ret = <optimized out>
#9  0x000055fe521cc2e4 in kmscon_seat_add_video (seat=<optimized out>, type=<optimized out>, flags=<optimized out>, node=0x55fe5ec57020 "/dev/dri/card0", udev=0x55fe5ec58390) at ../src/seat.c:985
        vid = <optimized out>
        ret = -12
#10 seat_monitor_new_dev (node=0x55fe5ec57020 "/dev/dri/card0", type=<optimized out>, flags=<optimized out>, data=<optimized out>, udev=0x55fe5ec58390) at ../src/seat.c:650
        seat = <optimized out>
#11 0x000055fe521d660d in uterm_monitor_scan (mon=0x55fe5eb50870, seat_name=<optimized out>) at ../src/uterm/monitor.c:687
        e = 0x55fe5ec11fc0
        entry = 0x55fe5ec74f90
        dev = 0x55fe5ec56e50
        path = <optimized out>
        ret = <optimized out>
#12 0x000055fe521c68e5 in uterm_monitor_scan (mon=<optimized out>, seat_name=<optimized out>) at ../src/uterm/monitor.c:639
        e = <optimized out>
        entry = <optimized out>
        dev = <optimized out>
        path = <optimized out>
        ret = <optimized out>
        out_enum = <optimized out>
#13 kmscon_seat_startup (seat=<optimized out>) at ../src/seat.c:1053
No locals.
#14 setup_seat (app=0x7fff63d753b0) at ../src/main.c:93
        ret = 0
#15 main (argc=<optimized out>, argv=<optimized out>) at ../src/main.c:221
        ret = <optimized out>
        conf_ctx = 0x55fe5eb18560
        conf = <optimized out>
        app = {conf_ctx = 0x55fe5eb18560, conf = 0x55fe5eb183c0, exiting = false, eloop = 0x55fe5eb1ae80, seat_ctx = 0x55fe5eb1ec90, seat_conf = 0x55fe5eb1eaf0, seat = 0x55fe5eb1e6e0, dbus = 0x55fe5eb1b3d0}

Line 83 of drm_shared.c is:

            for (j = 0; j < props->count_props: j++) {

If I'm reading the trace right, props is null, which is likely the issue?