CVE-2025-39833: mISDN: hfcpci: Fix warning when deleting uninitialized timer
In the Linux kernel, the following vulnerability has been resolved:
mISDN: hfcpci: Fix warning when deleting uninitialized timer
With CONFIGDEBUGOBJECTSTIMERS unloading hfcpci module leads to the following splat:
[ 250.215892] ODEBUG: assertinit not available (active state 0) object: ffffffffc01a3dc0 object type: timerlist hint: 0x0 [ 250.217520] WARNING: CPU: 0 PID: 233 at lib/debugobjects.c:612 debugprintobject+0x1b6/0x2c0 [ 250.218775] Modules linked in: hfcpci(-) mISDNcore [ 250.219537] CPU: 0 UID: 0 PID: 233 Comm: rmmod Not tainted 6.17.0-rc2-g6f713187ac98 #2 PREEMPT(voluntary) [ 250.220940] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 250.222377] RIP: 0010:debugprintobject+0x1b6/0x2c0 [ 250.223131] Code: fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 4f 41 56 48 8b 14 dd a0 4e 01 9f 48 89 ee 48 c7 c7 20 46 01 9f e8 cb 84d [ 250.225805] RSP: 0018:ffff888015ea7c08 EFLAGS: 00010286 [ 250.226608] RAX: 0000000000000000 RBX: 0000000000000005 RCX: ffffffff9be93a95 [ 250.227708] RDX: 1ffff1100d945138 RSI: 0000000000000008 RDI: ffff88806ca289c0 [ 250.228993] RBP: ffffffff9f014a00 R08: 0000000000000001 R09: ffffed1002bd4f39 [ 250.230043] R10: ffff888015ea79cf R11: 0000000000000001 R12: 0000000000000001 [ 250.231185] R13: ffffffff9eea0520 R14: 0000000000000000 R15: ffff888015ea7cc8 [ 250.232454] FS: 00007f3208f01540(0000) GS:ffff8880caf5a000(0000) knlGS:0000000000000000 [ 250.233851] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 250.234856] CR2: 00007f32090a7421 CR3: 0000000004d63000 CR4: 00000000000006f0 [ 250.236117] Call Trace: [ 250.236599] <TASK> [ 250.236967] ? traceirqenable.constprop.0+0xd4/0x130 [ 250.237920] debugobjectassertinit+0x1f6/0x310 [ 250.238762] ? pfxdebugobjectassertinit+0x10/0x10 [ 250.239658] ? lockacquire+0xdea/0x1c70 [ 250.240369] trytodeltimersync+0x69/0x140 [ 250.241172] ? pfxtrytodeltimersync+0x10/0x10 [ 250.242058] ? timerdeletesync+0xc6/0x120 [ 250.242842] ? lockacquire+0x30/0x80 [ 250.243474] ? timerdeletesync+0xc6/0x120 [ 250.244262] timerdeletesync+0x98/0x120 [ 250.245015] HFCcleanup+0x10/0x20 [hfcpci] [ 250.245704] dosysdeletemodule+0x348/0x510 [ 250.246461] ? pfxdosysdeletemodule+0x10/0x10 [ 250.247338] dosyscall64+0xc1/0x360 [ 250.247924] entrySYSCALL64afterhwframe+0x77/0x7f
Fix this by initializing hfctl timer with DEFINETIMER macro. Also, use modtimer instead of manual timeout update.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Fix the hfcpci module by initializing the hfc_tl timer with the DEFINE_TIMER macro (use mod_timer instead of manual timeout update). This addresses the warning when deleting an uninitialized timer during hfcpci cleanup/unload, as described in the resolved vulnerability.
Linux kernel module hfcpci hfc_tl timer initialization = DEFINE_TIMER macro
Event History
Frequently Asked Questions
What is the severity of CVE-2025-39833?
CVE-2025-39833 is categorized as a low severity vulnerability due to its specific conditions that lead to warnings rather than critical security risks.
How do I fix CVE-2025-39833?
To address CVE-2025-39833, ensure your Linux kernel is updated to the latest version where this vulnerability has been resolved.
Which Linux kernel versions are affected by CVE-2025-39833?
CVE-2025-39833 affects Linux kernel versions prior to the patch release that addressed the issue with CONFIG_DEBUG_OBJECTS_TIMERS.
What is the nature of the issue described in CVE-2025-39833?
CVE-2025-39833 involves a warning message that occurs when unloading the hfcpci module if CONFIG_DEBUG_OBJECTS_TIMERS is enabled.
Can CVE-2025-39833 be exploited remotely?
CVE-2025-39833 does not appear to be exploitable remotely as it requires specific module interactions in the kernel.