SUMMARY When entering the login screen, there is text that says (Or scan your fingerprint on the reader) (Or scan your smartcard) This text disappears after about a second. It shouldn't appear in the first place because by device doesnt support those login methods. STEPS TO REPRODUCE 1. Lock the session (Super+L) or wake device up from sleep (move cursor or press any key) OBSERVED RESULT The text appears then disappears after about a second. EXPECTED RESULT The text shouldnt appear in the first place when device does not support those login methods or does not have an external peripheral device attached which does. SOFTWARE/OS VERSIONS `kinfo` Operating System: Arch Linux KDE Plasma Version: 6.4.0 KDE Frameworks Version: 6.15.0 Qt Version: 6.9.1 Kernel Version: 6.15.2-arch1-1 (64-bit) Graphics Platform: Wayland Processors: 4 × AMD A8-7410 APU with AMD Radeon R5 Graphics Memory: 8 GiB of RAM (6.7 GiB usable) Graphics Processor: AMD Radeon R5 Graphics ADDITIONAL INFORMATION I don't have smartcard or fingerprint login set up. I use a regular password. Possible regression of https://bugs.kde.org/show_bug.cgi?id=487634 ?
Two questions: 1. You reported this agains plasma-login. Ar you actually using plasma-login, or did you mean SDDM? 2. When you say the login screen, do you mean the lock screen? The SDDM login screen has no support for this at all.
I have also encountered this issue. This should likely be filled under plasmashell -> Screen locking, as in bug 487634. kinfo output: Operating System: Arch Linux KDE Plasma Version: 6.4.1 KDE Frameworks Version: 6.15.0 Qt Version: 6.9.1 Kernel Version: 6.15.3-arch1-1 (64-bit) Graphics Platform: Wayland Processors: 8 × Intel® Core™ i5-8350U CPU @ 1.70GHz Memory: 16 GiB of RAM (15.5 GiB usable) Graphics Processor: Intel® UHD Graphics 620
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Hi, I'd be happy more than happy to answer any questions regarding this bug - I can still reproduce this issue on the newest (6.4.2/6.16.0) KDE version. Sidenote - I can't seem to be able to change the component from general to Screen locking. Could anyone change it to the correct one? Thanks!
As an end-user, how am i meant to know exactly which component it is? idk for sure if its login screen, lock screen or SDDM. All are essentially the same to me. Even if it's not quite the right place, i feel like its worth mentioning anyway so that something can be done about it. Follow the steps to reproduce the bug and it's that screen that i'm on about.
Can reproduce on a KDE Linux system that's had PAM set up for fingerprint auth. The text briefly appears on the lock screen despite the system not actually having fingerprint reader hardware. We should probably conditionalize the text's appearance on the user having actually set up the system for using a fingerprint reader.
Indeed, the problem is here: https://invent.kde.org/plasma/plasma-desktop/-/blob/master/desktoppackage/contents/lockscreen/MainBlock.qml#L131 That code takes into account only that an authentication type is supported on the system in theory, not that the hardware for it is present, or that the user has indicated they wish to use it. There's a bit of code in the Users KCM that can detect the presence of a fingerprint reader device that could perhaps be moved up a level and used here: https://invent.kde.org/plasma/plasma-workspace/-/blob/master/kcms/users/src/fingerprintmodel.cpp#L79 And then we'd have to do the same thing for smartcards.
I have been experiencing this problem for some time as well, even though this is a desktop computer without a fingerprint reader or smartcard. The problem is directly related to '/usr/share/plasma/shells/org.kde.plasma.desktop/contents/lockscreen/MainBlock.qml', that is, the 'plasma-desktop' package. I don't even have the 'fprintd' package installed. In '/etc/pam.d/' there are files named 'kde-fingerprint' and 'kde-smartcard', which are part of the 'kscreenlocker' package. I tried commenting out '-auth required pam_fprintd.so', but this causes the screen lock not to ask for a password; there is only an 'unlock' button. Moreover, with 'fairlock' configured, using this button locks the entire user account. kinfo output: Operating System: Arch Linux KDE Plasma Version: 6.4.4 KDE Frameworks Version: 6.17.0 Qt Version: 6.9.1 Kernel Version: 6.16.3-arch1-1 (64-bit) Graphics Platform: Wayland Processors: 8 × Intel® Core™ i7-4790K CPU @ 4.00GHz Memory: 16 GiB of RAM (15.6 GiB usable) Graphics Processor: NVIDIA GeForce GTX 980 Manufacturer: ASUS Product Name: All Series
*** Bug 509542 has been marked as a duplicate of this bug. ***
(In reply to Nate Graham from comment #7) > There's a bit of code in the Users KCM that can detect the presence of a > fingerprint reader device that could perhaps be moved up a level and used > here: > https://invent.kde.org/plasma/plasma-workspace/-/blob/master/kcms/users/src/ > fingerprintmodel.cpp#L79 > > And then we'd have to do the same thing for smartcards. Hi, what would be a good way of moving fingerprint related code up a level? Something like plasma-workspace/libfingerprint ?
https://invent.kde.org/plasma/kscreenlocker/-/merge_requests/296
Git commit 5c2e6e1e877c1a0ecd915d4b91773cf9c56734e6 by David Edmundson, on behalf of Fushan Wen. Committed on 12/12/2025 at 19:09. Pushed by davidedmundson into branch 'master'. greeter: fix hanging when unlocking via loginctl over KDE Connect `fail_delay` used to sleep in the thread, which blocks the screen locker from quiting when another unlock attempt succeeds. This records the next attempt allowed time point in each worker and checks it in `PamWorker::authenticate()` to make sure a previous failing worker doesn't affect other successful attempts to unlock the screen. How to reproduce: 1. Meta + L 2. Move the mouse so the password input field appears (IMPORTANT) 3. Run unlock via KDE connect 4. Observe frozen screen/black screen if mouse is moved Related: bug 506343 FIXED-IN: 6.5.4 M +13 -4 greeter/pamauthenticator.cpp https://invent.kde.org/plasma/kscreenlocker/-/commit/5c2e6e1e877c1a0ecd915d4b91773cf9c56734e6
Git commit b4f2195ecbfa4bee36ade689c7f24d9dde300dbd by Fushan Wen. Committed on 13/12/2025 at 03:02. Pushed by fusionfuture into branch 'Plasma/6.5'. 🍒greeter: fix hanging when unlocking via loginctl over KDE Connect `fail_delay` used to sleep in the thread, which blocks the screen locker from quiting when another unlock attempt succeeds. This records the next attempt allowed time point in each worker and checks it in `PamWorker::authenticate()` to make sure a previous failing worker doesn't affect other successful attempts to unlock the screen. How to reproduce: 1. Meta + L 2. Move the mouse so the password input field appears (IMPORTANT) 3. Run unlock via KDE connect 4. Observe frozen screen/black screen if mouse is moved Related: bug 506343 FIXED-IN: 6.5.5 (cherry picked from commit 5c2e6e1e877c1a0ecd915d4b91773cf9c56734e6) Co-authored-by: Fushan Wen <qydwhotmail@gmail.com> M +13 -4 greeter/pamauthenticator.cpp https://invent.kde.org/plasma/kscreenlocker/-/commit/b4f2195ecbfa4bee36ade689c7f24d9dde300dbd