Hyprlock/Hyprland crash investigation: multiple causes and fixes (DPMS, suspend, PAM)

[brenoperucchi]

System Info

• Hyprlock: 0.9.2
• Hyprland: 0.53.1
• OS: Arch Linux (kernel 6.18.3)
• GPU: AMD Radeon RX 470/480/570/580 (amdgpu driver)

Summary

After weeks of investigating repeated Hyprland crashes during idle/lock states, I found multiple independent issues that can cause crashes. Documenting all of them here to help others.

---

Issue 1: DPMS off crashes Hyprland (AMD GPU)

Symptom: Hyprland crashes when DPMS turns off monitors.

Cause: Known AMD GPU issue with DPMS in Hyprland.

Fix: Remove DPMS off from hypridle config.

Related: hyprwm/Hyprland#2578

---

Issue 2: Monitor disable crashes Hyprlock

Symptom: Hyprlock crashes when monitors are disabled via hyprctl dispatch dpms off or monitor power management.

Cause: Hyprlock cannot handle displays becoming unavailable.

Fix: Do not disable monitors while hyprlock is running. Keep system in screensaver + lock only.

Related: #434, #480

---

Issue 3: AMD GPU suspend issues

Symptom: System freezes or crashes on suspend/resume.

Cause: AMD GPU runtime power management issues.

Fix: Add kernel parameters:

amdgpu.runpm=0 mem_sleep_default=deep

---

Issue 4: Fingerprint auth crash ("User unknown")

Symptom: Hyprlock crashes with "User unknown" PAM error.

Cause: fingerprint:enabled = true in hyprlock.conf but fprintd is not installed.

Fix: Disable fingerprint in hyprlock.conf:

# auth {
#     fingerprint:enabled = true
# }

---

Issue 5: Missing PAM header

Symptom: PAM authentication fails silently.

Cause: /etc/pam.d/hyprlock missing #%PAM-1.0 header.

Fix: Ensure file starts with #%PAM-1.0.

---

Issue 6: Incomplete PAM configuration (pam_end crash) - NEW

Symptom: Hyprlock crashes with SIGABRT in pam_end(), then Hyprland crashes.

Stack trace:

#0  pam_end (libpam.so.0 + 0x4b4b)
#1  /usr/bin/hyprlock + 0x416a1
#2  /usr/bin/hyprlock + 0x41964
#3  execute_native_thread_routine (libstdc++.so.6)

Cause: The default /etc/pam.d/hyprlock from Arch package only has:

#%PAM-1.0
auth        include     login

Missing account and session sections. When pam_end() is called, it tries to clean up session handles that were never initialized, causing a crash.

Fix: Complete PAM configuration:

#%PAM-1.0

auth        include     system-login
account     include     system-login
session     optional    pam_keyinit.so    force revoke
session     include     system-login

---

Final working hypridle.conf

general {
    lock_cmd = hyprlock
    before_sleep_cmd = loginctl lock-session
    after_sleep_cmd = hyprctl dispatch dpms on
}

listener {
    timeout = 600   # 10min - screensaver
    on-timeout = pidof hyprlock || hyprlock
}

listener {
    timeout = 900   # 15min - lock
    on-timeout = loginctl lock-session
}

# NO DPMS off - causes crash on AMD
# NO monitor disable - causes hyprlock crash

---

Suggestion

The hyprlock package should ship with a complete PAM configuration (like SDDM does) to prevent the pam_end crash.

Related Issues

• Hyprlock crashes when no display available. #434 - Hyprlock crashes when no display available
• Manual configuration used to disable display on clamshell breaks hyprlock #480 - Crash on monitor disable
• Hyprlock + Hyprland crashes when locking #942 - Hyprlock + Hyprland crashes when locking
• Hyprland crashes with dpms off after a while Hyprland#2578 - DPMS crash on AMD

[brenoperucchi]

Crash logs (coredumpctl info)

           PID: 103731 (hyprlock)
           UID: 1000 (brenoperucchi)
           GID: 1000 (brenoperucchi)
        Signal: 6 (ABRT)
     Timestamp: Mon 2026-01-26 10:33:42 -03
  Command Line: hyprlock
    Executable: /usr/bin/hyprlock
 Control Group: /user.slice/user-1000.slice/user@1000.service/app.slice/app-graphical.slice/app-Hyprland-hypridle-a1913bc1.scope
          Unit: user@1000.service
     User Unit: app-Hyprland-hypridle-a1913bc1.scope
         Slice: user-1000.slice
     Owner UID: 1000 (brenoperucchi)
       Storage: /var/lib/systemd/coredump/core.hyprlock.1000.afc796f3e51a45e2a2a02fc6b0e13e57.103731.1769434422000000.zst (present)
  Size on Disk: 2.9M
       Message: Process 103731 (hyprlock) of user 1000 dumped core.

                Stack trace of thread 103751 (PAM thread - CRASHED):
                #0  0x00007f5fb929890c n/a (libc.so.6 + 0x9890c)
                #1  0x00007f5fb923e3a0 raise (libc.so.6 + 0x3e3a0)
                #2  0x00007f5fb922557a abort (libc.so.6 + 0x2557a)
                #3  0x00007f5fb9226613 n/a (libc.so.6 + 0x26613)
                #4  0x00007f5fb92a2d25 n/a (libc.so.6 + 0xa2d25)
                #5  0x00007f5fb92a4ff6 n/a (libc.so.6 + 0xa4ff6)
                #6  0x00007f5fb9fb9b4b pam_end (libpam.so.0 + 0x4b4b)  <-- CRASH HERE
                #7  0x00005640ce1846a1 n/a (/usr/bin/hyprlock + 0x416a1)
                #8  0x00005640ce184964 n/a (/usr/bin/hyprlock + 0x41964)
                #9  0x00007f5fb96e55a4 execute_native_thread_routine (libstdc++.so.6 + 0xe55a4)
                #10 0x00007f5fb929698b n/a (libc.so.6 + 0x9698b)
                #11 0x00007f5fb931a9cc n/a (libc.so.6 + 0x11a9cc)

                Stack trace of thread 103731 (main):
                #0  0x00007f5fb929f002 n/a (libc.so.6 + 0x9f002)
                #1  0x00007f5fb929316c n/a (libc.so.6 + 0x9316c)
                #2  0x00007f5fb92937dc n/a (libc.so.6 + 0x937dc)
                #3  0x00007f5fb92962d2 pthread_cond_clockwait (libc.so.6 + 0x962d2)
                #4  0x00005640ce1ad954 n/a (/usr/bin/hyprlock + 0x6a954)
                #5  0x00005640ce16782f n/a (/usr/bin/hyprlock + 0x2482f)
                #6  0x00007f5fb9227635 n/a (libc.so.6 + 0x27635)
                #7  0x00007f5fb92276e9 __libc_start_main (libc.so.6 + 0x276e9)
                #8  0x00005640ce16a615 n/a (/usr/bin/hyprlock + 0x27615)

                (+ 20 gallium GPU threads waiting on pthread_cond_wait)

                ELF object binary architecture: AMD x86-64

Original broken /etc/pam.d/hyprlock (from Arch package)

#%PAM-1.0
auth        include     login

Fixed /etc/pam.d/hyprlock

#%PAM-1.0

auth        include     system-login
account     include     system-login
session     optional    pam_keyinit.so    force revoke
session     include     system-login

[brenoperucchi]

Additional Info (per issue template)

Hyprlock config (~/.config/hypr/hyprlock.conf)

source = ~/.config/omarchy/current/theme/hyprlock.conf

general {
    ignore_empty_input = true
}

background {
    monitor =
    color = $color
    path = ~/.config/omarchy/current/background
    blur_passes = 3
}

animations {
    enabled = false
}

input-field {
    monitor =
    size = 650, 100
    position = 0, 0
    halign = center
    valign = center

    inner_color = $inner_color
    outer_color = $outer_color
    outline_thickness = 4

    font_family = SF Mono
    font_color = $font_color

    placeholder_text = Enter Password
    check_color = $check_color
    fail_text = <i>$FAIL ($ATTEMPTS)</i>

    rounding = 0
    shadow_passes = 0
    fade_on_empty = false
}

# Fingerprint disabled - fprintd not installed (causes "User unknown" crash)
# auth {
#     fingerprint:enabled = true
# }

System/Version info (hyprctl systeminfo)

Hyprland 0.53.1 built from branch v0.53.1 at commit ab1d80f3d6aebd57a0971b53a1993b1c1dfe0b09 clean (version: bump to 0.53.1).
Date: Fri Jan 2 21:20:57 2026
Tag: v0.53.1, commits: 6766

Libraries:
Hyprgraphics: built against 0.5.0, system has 0.5.0
Hyprutils: built against 0.11.0, system has 0.11.0
Hyprcursor: built against 0.1.13, system has 0.1.13
Hyprlang: built against 0.6.7, system has 0.6.8
Aquamarine: built against 0.10.0, system has 0.10.0

Version ABI string: ab1d80f3d6aebd57a0971b53a1993b1c1dfe0b09_aq_0.10_hu_0.11_hg_0.5_hc_0.1_hlg_0.6
no flags were set

System Information:
System name: Linux
Node name: omarchy
Release: 6.18.3-arch1-1
Version: #1 SMP PREEMPT_DYNAMIC Fri, 02 Jan 2026 17:52:55 +0000

GPU information: 
01:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon RX 470/480/570/570X/580/580X/590] [1002:67df] (rev e7)

os-release: NAME="Arch Linux"
PRETTY_NAME="Arch Linux"
ID=arch
BUILD_ID=rolling

plugins: (none)

Explicit sync: supported
GL ver: 3.2
Backend: drm

Monitor info:
    Panel DP-2: 5120x1440, Philips PHL 499P9 (HDR, VRR capable)
    Panel DP-3: 2560x1080, LG ULTRAWIDE
    Panel HDMI-A-1: 2560x1080, LG ULTRAWIDE

Hyprlock version: v0.9.2

[brenoperucchi]

Update: Crash persists after PAM fix

The crash in pam_end continues even after adding the complete PAM configuration with account and session sections.

New crash (2026-01-27 01:45:54):

Stack trace of thread 1114605:
#0  0x00007f43e5e9890c n/a (libc.so.6 + 0x9890c)
#1  0x00007f43e5e3e3a0 raise (libc.so.6 + 0x3e3a0)
#2  0x00007f43e5e2557a abort (libc.so.6 + 0x2557a)
#3  0x00007f43e5e26613 n/a (libc.so.6 + 0x26613)
#4  0x00007f43e5ea2d25 n/a (libc.so.6 + 0xa2d25)
#5  0x00007f43e5ea4ff6 n/a (libc.so.6 + 0xa4ff6)
#6  0x00007f43e6ba6b4b pam_end (libpam.so.0 + 0x4b4b)  <-- CRASH
#7  0x0000560bd6bbc6a1 n/a (/usr/bin/hyprlock + 0x416a1)
#8  0x0000560bd6bbc964 n/a (/usr/bin/hyprlock + 0x41964)

The abort comes from libc's memory allocation checks (addresses 0xa2d25, 0xa4ff6), suggesting double-free or memory corruption in hyprlock's PAM handling code.

Current /etc/pam.d/hyprlock:

#%PAM-1.0

auth        include     system-login
account     include     system-login
session     optional    pam_keyinit.so    force revoke
session     include     system-login

This appears to be a bug in hyprlock itself, not a configuration issue.

[RazeLighter777]

Getting this as well.

Jan 28 11:46:01 suesslenovo hyprlock[512808]: pam_unix(hyprlock:auth): unix_chkpwd abnormal exit: 159
Jan 28 11:46:01 suesslenovo hyprlock[512808]: pam_unix(hyprlock:auth): authentication failure; logname=justin uid=1000 euid=1000 tty= ruser= rhost=  user=justin
Jan 28 11:46:01 suesslenovo hyprlock[512808]: pam_kwallet5(hyprlock:auth): pam_kwallet5: pam_sm_authenticate
Jan 28 11:46:01 suesslenovo systemd-coredump[513508]: Process 513506 (hyprlock) of user 1000 dumped core.
                                                      
                                                      Module /nix/store/y6bm9cxwqy3ws7x359cpyrxfb1pakimc-hyprlock-0.9.2/bin/hyprlock without build-id.
                                                      Module libpcsclite.so without build-id.
                                                      Module libopensc.so.12 without build-id.
                                                      Module opensc-pkcs11.so without build-id.
                                                      Module pam_warn.so without build-id.
                                                      Module pam_limits.so without build-id.
                                                      Module pam_env.so without build-id.
                                                      Module pam_deny.so without build-id.
                                                      Module pam_gnupg.so without build-id.
                                                      Module libgpg-error.so.0 without build-id.
                                                      Module libgcrypt.so.20 without build-id.
                                                      Module libp11.so.3 without build-id.
                                                      Module pam_p11.so without build-id.
                                                      Module libcrypt.so.2 without build-id.
                                                      Module pam_unix.so without build-id.
                                                      Module libpcsclite_real.so.1 without build-id.
                                                      Module libpciaccess.so.0 without build-id.
                                                      Module liblzma.so.5 without build-id.
                                                      Module libdrm_intel.so.1 without build-id.
                                                      Module libdrm_amdgpu.so.1 without build-id.
                                                      Module libxshmfence.so.1 without build-id.
                                                      Module libxcb-sync.so.1 without build-id.
                                                      Module libsensors.so.5 without build-id.
                                                      Module libzstd.so.1 without build-id.
                                                      Module libxcb-present.so.0 without build-id.
                                                      Module libxcb-dri3.so.0 without build-id.
                                                      Module libxcb-xfixes.so.0 without build-id.
                                                      Module libxcb-randr.so.0 without build-id.
                                                      Module libX11-xcb.so.1 without build-id.
                                                      Module liblcms2.so.2 without build-id.
                                                      Module libbrotlienc.so.1 without build-id.
                                                      Module libbrotlicommon.so.1 without build-id.
                                                      Module libxml2.so.16 without build-id.
                                                      Module libdav1d.so.7 without build-id.
                                                      Module libsharpyuv.so.0 without build-id.
                                                      Module libXdmcp.so.6 without build-id.
                                                      Module libXau.so.6 without build-id.
                                                      Module libdatrie.so.1 without build-id.
                                                      Module libselinux.so.1 without build-id.
                                                      Module libexpat.so.1 without build-id.
                                                      Module libbrotlidec.so.1 without build-id.
                                                      Module libbz2.so.1 without build-id.
                                                      Module libcap-ng.so.0 without build-id.
                                                      Module libjxl_threads.so.0.11 without build-id.
                                                      Module libjxl_cms.so.0.11 without build-id.
                                                      Module libjxl.so.0.11 without build-id.
                                                      Module librsvg-2.so.2 without build-id.
                                                      Module libmagic.so.1 without build-id.
                                                      Module libwebp.so.7 without build-id.
                                                      Module libjpeg.so.62 without build-id.
                                                      Module libcap.so.2 without build-id.
                                                      Module libxcb-shm.so.0 without build-id.
                                                      Module libxcb-render.so.0 without build-id.
                                                      Module libxcb.so.1 without build-id.
                                                      Module libXrender.so.1 without build-id.
                                                      Module libXext.so.6 without build-id.
                                                      Module libX11.so.6 without build-id.
                                                      Module libpng16.so.16 without build-id.
                                                      Module libz.so.1 without build-id.
                                                      Module libgraphite2.so.3 without build-id.
                                                      Module libfreetype.so.6 without build-id.
                                                      Module libpcre2-8.so.0 without build-id.
                                                      Module libthai.so.0 without build-id.
                                                      Module libfribidi.so.0 without build-id.
                                                      Module libfontconfig.so.1 without build-id.
                                                      Module libpangoft2-1.0.so.0 without build-id.
                                                      Module libffi.so.8 without build-id.
                                                      Module libGLdispatch.so.0 without build-id.
                                                      Module libaudit.so.1 without build-id.
                                                      Module libgcc_s.so.1 without build-id.
                                                      Module libstdc++.so.6 without build-id.
                                                      Module libhyprgraphics.so.4 without build-id.
                                                      Module libsdbus-c++.so.2 without build-id.
                                                      Module libhyprutils.so.10 without build-id.
                                                      Module libgbm.so.1 without build-id.
                                                      Module libdrm.so.2 without build-id.
                                                      Module libharfbuzz.so.0 without build-id.
                                                      Module libpango-1.0.so.0 without build-id.
                                                      Module libpangocairo-1.0.so.0 without build-id.
                                                      Module libxkbcommon.so.0 without build-id.
                                                      Module libhyprlang.so.2 without build-id.
                                                      Module libGLESv2.so.2 without build-id.
                                                      Module libEGL.so.1 without build-id.
                                                      Module libpam.so.0 without build-id.
                                                      Stack trace of thread 513506:
                                                      #0  0x00007f5798e9b50a __nptl_setxid (libc.so.6 + 0x9b50a)
                                                      #1  0x00007f5798f0bf76 setuid (libc.so.6 + 0x10bf76)
                                                      #2  0x00007f5788a7369e _unix_run_helper_binary (pam_unix.so + 0x569e)
                                                      #3  0x00007f5788a74c85 _unix_verify_password (pam_unix.so + 0x6c85)
                                                      #4  0x00007f5788a7226b pam_sm_authenticate (pam_unix.so + 0x426b)
                                                      #5  0x00007f5799f206df _pam_dispatch (libpam.so.0 + 0x46df)
                                                      #6  0x00007f5799f1fdb2 pam_authenticate (libpam.so.0 + 0x3db2)
                                                      #7  0x000055722f70012e _ZN4CPam4authEv (/nix/store/y6bm9cxwqy3ws7x359cpyrxfb1pakimc-hyprlock-0.9.2/bin/hyprlock + 0x5512e)
                                                      #8  0x000055722f700359 _ZNSt6thread11_State_implINS_8_InvokerISt5tupleIJZN4CPam4initEvEUlvE_EEEEE6_M_runEv (/nix/store/y6bm9cxwqy3ws7x359cpyrxfb1pakimc-hyprlock-0.9.2/bin/hyprlock + 0x55359)
                                                      #9  0x00007f57992f2fa4 execute_native_thread_routine (libstdc++.so.6 + 0xf2fa4)
                                                      #10 0x00007f5798e9dd53 start_thread (libc.so.6 + 0x9dd53)
                                                      #11 0x00007f5798f255fc __clone3 (libc.so.6 + 0x1255fc)
                                                      ELF object binary architecture: AMD x86-64
Jan 28 11:46:01 suesslenovo hyprlock[512808]: pam_unix(hyprlock:auth): unix_chkpwd abnormal exit: 159

Seems to be crashing in the PAM code at pam_authenticate

[RazeLighter777]

I have a fix for number 6 here @brenoperucchi in my PR #954

[tekstryder]

I've hit two of these #6 crashes past week or so:

Mon 2026-02-02 12:30:27 EST  95319 1000 1000 SIGABRT present  /usr/bin/hyprlock                                                     >
Tue 2026-02-10 06:50:17 EST 637788 1000 1000 SIGABRT present  /usr/bin/hyprlock 

(gdb) bt
#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
#1  0x00007f7dc24a79d3 in __pthread_kill_internal (threadid=<optimized out>, signo=6) at pthread_kill.c:89
#2  0x00007f7dc244d3a0 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#3  0x00007f7dc243457a in __GI_abort () at abort.c:77
#4  0x00007f7dc2435613 in __libc_message_impl (fmt=fmt@entry=0x7f7dc25c233d "%s\n") at ../sysdeps/posix/libc_fatal.c:138
#5  0x00007f7dc24b1d25 in malloc_printerr (str=str@entry=0x7f7dc25c5590 "free(): invalid next size (fast)") at malloc.c:5895
#6  0x00007f7dc24b3ff6 in _int_free_chunk (av=<optimized out>, p=<optimized out>, size=<optimized out>, have_lock=have_lock@entry=0)
    at malloc.c:4670
#7  0x00007f7dc24b6ff4 in __GI___libc_free (mem=<optimized out>) at malloc.c:3571
#8  0x00007f7dc2f82c6b in pam_end (pamh=0x7f7d90000df0, pam_status=10) at ../pam/libpam/pam_end.c:58
#9  0x0000560dddfe46a1 in CPam::auth (this=0x560e058a93f0) at /usr/src/debug/hyprlock/hyprlock-0.9.2/src/auth/Pam.cpp:123
#10 0x0000560dddfe4964 in operator() (__closure=0x560e058db808) at /usr/src/debug/hyprlock/hyprlock-0.9.2/src/auth/Pam.cpp:92
#11 std::__invoke_impl<void, CPam::init()::<lambda()> > (__f=...) at /usr/include/c++/15.2.1/bits/invoke.h:63
#12 std::__invoke<CPam::init()::<lambda()> > (__fn=...) at /usr/include/c++/15.2.1/bits/invoke.h:98
#13 std::thread::_Invoker<std::tuple<CPam::init()::<lambda()> > >::_M_invoke<0> (this=0x560e058db808)
    at /usr/include/c++/15.2.1/bits/std_thread.h:303
#14 std::thread::_Invoker<std::tuple<CPam::init()::<lambda()> > >::operator() (this=0x560e058db808)
    at /usr/include/c++/15.2.1/bits/std_thread.h:310
#15 std::thread::_State_impl<std::thread::_Invoker<std::tuple<CPam::init()::<lambda()> > > >::_M_run(void) (this=0x560e058db800)
    at /usr/include/c++/15.2.1/bits/std_thread.h:255
#16 0x00007f7dc26e55a4 in std::execute_native_thread_routine (__p=0x560e058db800)
    at /usr/src/debug/gcc/gcc/libstdc++-v3/src/c++11/thread.cc:104
#17 0x00007f7dc24a598b in start_thread (arg=<optimized out>) at pthread_create.c:448
#18 0x00007f7dc2529a0c in __GI___clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78

I'll build hyprlock from git + #954 and see if it helps.

[tekstryder]

I've made 3 changes in an attempt to mitigate this issue:

1. built hyprlock from git + pam: add check for handle before pam_end #954
2. disabled hyprlock animations
3. limited hyprlock to only primary display monitor = DP-1

No crashes or auth failures for 3 days now.

I'll report back in one month (mid-March).

[tekstryder]

Doh, #954 was closed. So now I'm on unpatched git at 5ba5ff5.

Still no crashes or pam shenanigans after a full week with config modified to:

• disable hyprlock animations
• limit hyprlock to only the primary display monitor = DP-1