{"cve":"CVE-2026-98741","nvd":{"published":"2026-10-18T16:17:27.807","modified":"2026-10-21T13:21:41.467","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: ua101: reject mismatched capture/playback packet sizes\n\ndetect_usb_format() cross-checks bSubframeSize, bBitResolution and\ntSamFreq between the capture and playback interfaces, but never relates\nthe two endpoints' wMaxPacketSize and bNrChannels.  Each playback URB\ngets a buffer of ua->playback.max_packet_bytes, while the number of\nbytes written into it is derived from the capture stream:\ncapture_urb_complete() computes frames from the received capture packet\nand capture.frame_bytes, and start_usb_playback() and playback_work()\nmultiply that by playback.frame_bytes.\n\nA device declaring a large capture wMaxPacketSize with few capture\nchannels and a small playback wMaxPacketSize with many playback channels\ntherefore memset()s and memcpy()s past the end of the playback buffer,\nin open() of the PCM node the driver registers during probe.\nusb_submit_urb() rejects the over-long iso_frame_desc[0].length with\n-EMSGSIZE, but only after the write.\n\nReject such descriptors at probe time.  Genuine UA-101/UA-1000 hardware\ndeclares proportional packet sizes and is unaffected.\n\n  BUG: KASAN: slab-out-of-bounds in start_usb_playback (sound/usb/misc/ua101.c:586)\n  Write of size 2048 at addr ffff8881098f3c00 by task exploit/5021\n  Call Trace:\n   __asan_memset (mm/kasan/shadow.c:84)\n   start_usb_playback (sound/usb/misc/ua101.c:586)\n   playback_pcm_open (sound/usb/misc/ua101.c:679)\n   snd_pcm_open_substream (sound/core/pcm_native.c:2829)\n   snd_pcm_open (sound/core/pcm_native.c:2865 sound/core/pcm_native.c:2932)\n   snd_pcm_playback_open (sound/core/pcm_native.c:2891)\n   snd_open (sound/core/sound.c:166)\n   chrdev_open (fs/char_dev.c:411)\n   do_dentry_open (fs/open.c:996)\n   vfs_open (fs/open.c:1101)\n   path_openat (fs/namei.c:4837 fs/namei.c:5000)\n   do_file_open (fs/namei.c:5029)\n   do_sys_openat2 (fs/open.c:1417)\n   __x64_sys_openat (fs/open.c:1423 fs/open.c:1439 fs/open.c:1434)\n   do_syscall_64 (arch/x86/entry/syscall_64.c:61 arch/x86/entry/syscall_64.c:84)\n   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n\n  The buggy address belongs to the object at ffff8881098f3c00\n   which belongs to the cache kmalloc-192 of size 192\n  The buggy address is located 0 bytes inside of\n   allocated 168-byte region [ffff8881098f3c00, ffff8881098f3ca8)","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/4294fe57048594a9e158b61c967bb7f943cda477","https://git.kernel.org/stable/c/86f86e6fdedc33c5b8d38b9208b350f8accf57ee","https://git.kernel.org/stable/c/ada5ded765f059a6e3036e69ca350449442af0fc","https://git.kernel.org/stable/c/eb0c7fda59cf650076f8ed5b949a6c8441aa3606","https://git.kernel.org/stable/c/fd3a7bf0d988b0878a1957df150edb35f81db87e"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-98741","score":0.00168,"percentile":0.05981,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}