CVE-2025-68180
Description
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix NULL deref in debugfs odm_combine_segments
When a connector is connected but inactive (e.g., disabled by desktop environments), pipe_ctx->stream_res.tg will be destroyed. Then, reading odm_combine_segments causes kernel NULL pointer dereference.
BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 16 UID: 0 PID: 26474 Comm: cat Not tainted 6.17.0+ #2 PREEMPT(lazy) e6a17af9ee6db7c63e9d90dbe5b28ccab67520c6 Hardware name: LENOVO 21Q4/LNVNB161216, BIOS PXCN25WW 03/27/2025 RIP: 0010:odm_combine_segments_show+0x93/0xf0 [amdgpu] Code: 41 83 b8 b0 00 00 00 01 75 6e 48 98 ba a1 ff ff ff 48 c1 e0 0c 48 8d 8c 07 d8 02 00 00 48 85 c9 74 2d 48 8b bc 07 f0 08 00 00 <48> 8b 07 48 8b 80 08 02 00> RSP: 0018:ffffd1bf4b953c58 EFLAGS: 00010286 RAX: 0000000000005000 RBX: ffff8e35976b02d0 RCX: ffff8e3aeed052d8 RDX: 00000000ffffffa1 RSI: ffff8e35a3120800 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff8e3580eb0000 R09: ffff8e35976b02d0 R10: ffffd1bf4b953c78 R11: 0000000000000000 R12: ffffd1bf4b953d08 R13: 0000000000040000 R14: 0000000000000001 R15: 0000000000000001 FS: 00007f44d3f9f740(0000) GS:ffff8e3caa47f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000006485c2000 CR4: 0000000000f50ef0 PKRU: 55555554 Call Trace:
seq_read_iter+0x125/0x490 ? __alloc_frozen_pages_noprof+0x18f/0x350 seq_read+0x12c/0x170 full_proxy_read+0x51/0x80 vfs_read+0xbc/0x390 ? __handle_mm_fault+0xa46/0xef0 ? do_syscall_64+0x71/0x900 ksys_read+0x73/0xf0 do_syscall_64+0x71/0x900 ? count_memcg_events+0xc2/0x190 ? handle_mm_fault+0x1d7/0x2d0 ? do_user_addr_fault+0x21a/0x690 ? exc_page_fault+0x7e/0x1a0 entry_SYSCALL_64_after_hwframe+0x6c/0x74 RIP: 0033:0x7f44d4031687 Code: 48 89 fa 4c 89 df e8 58 b3 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00> RSP: 002b:00007ffdb4b5f0b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f44d3f9f740 RCX: 00007f44d4031687 RDX: 0000000000040000 RSI: 00007f44d3f5e000 RDI: 0000000000000003 RBP: 0000000000040000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007f44d3f5e000 R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000040000
Modules linked in: tls tcp_diag inet_diag xt_mark ccm snd_hrtimer snd_seq_dummy snd_seq_midi snd_seq_oss snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device x> snd_hda_codec_atihdmi snd_hda_codec_realtek_lib lenovo_wmi_helpers think_lmi snd_hda_codec_generic snd_hda_codec_hdmi snd_soc_core kvm snd_compress uvcvideo sn> platform_profile joydev amd_pmc mousedev mac_hid sch_fq_codel uinput i2c_dev parport_pc ppdev lp parport nvme_fabrics loop nfnetlink ip_tables x_tables dm_cryp> CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- RIP: 0010:odm_combine_segments_show+0x93/0xf0 [amdgpu] Code: 41 83 b8 b0 00 00 00 01 75 6e 48 98 ba a1 ff ff ff 48 c1 e0 0c 48 8d 8c 07 d8 02 00 00 48 85 c9 74 2d 48 8b bc 07 f0 08 00 00 <48> 8b 07 48 8b 80 08 02 00> RSP: 0018:ffffd1bf4b953c58 EFLAGS: 00010286 RAX: 0000000000005000 RBX: ffff8e35976b02d0 RCX: ffff8e3aeed052d8 RDX: 00000000ffffffa1 RSI: ffff8e35a3120800 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff8e3580eb0000 R09: ffff8e35976b02d0 R10: ffffd1bf4b953c78 R11: 0000000000000000 R12: ffffd1bf4b953d08 R13: 0000000000040000 R14: 0000000000000001 R15: 0000000000000001 FS: 00007f44d3f9f740(0000) GS:ffff8e3caa47f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000006485c2000 CR4: 0000000000f50ef0 PKRU: 55555554
Fix this by checking pipe_ctx-> ---truncated---
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
A NULL pointer dereference in the Linux kernel's AMD GPU display driver can be triggered by reading debugfs 'odm_combine_segments' when a connector is inactive.
Root
Cause
The vulnerability is a NULL pointer dereference in the odm_combine_segments_show function within the AMD GPU display driver (amdgpu). When a connector is physically connected but has been disabled by the desktop environment, the associated pipe_ctx->stream_res.tg (target pointer) is destroyed but not NULL-checked before being dereferenced during debugfs read operations [1][2]. This leads to a kernel crash with a NULL pointer access.
Attack
Vector
An attacker with local access can trigger the issue by reading the debugfs file odm_combine_segments for a connector that is in a disabled state. No special privileges beyond local user access are required, as debugfs files are typically readable by all users. The prerequisite is that a display connector is present but has been deactivated by the display manager or user action [1][2].
Impact
When the debugfs file is read under these conditions, the kernel experiences a NULL pointer dereference, causing an immediate system crash (Oops) resulting in a denial of service (DoS). An attacker could repeatedly trigger this to render the system unstable or unusable. The crash log shows a kernel panic in odm_combine_segments_show with an attempt to read from address 0x0000000000000000 [1][2].
Mitigation
The fix is included in Linux kernel stable updates. The commit c05fe5d47baa (and its backport 6dd97ceb645c) add a NULL check before accessing tg in the odm_combine_segments_show function, preventing the dereference [1][2]. Users should update to a kernel version containing this commit. No workaround exists aside from not reading the affected debugfs file on systems with inactive displays.
AI Insight generated on May 19, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.
Affected products
2Patches
0No patches discovered yet.
Vulnerability mechanics
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References
3News mentions
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