{"schema":"threatline.record/2","record":{"id":"CVE-2026-98741","aliases":[],"summary":"ALSA: ua101: reject mismatched capture/playback packet sizes","details":"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)","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98741","source_modified_at":"2026-10-21T12:56:16.734Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"63978ab3e3e963db28093b53bb4598f2702e1ad7","lessThan":"ada5ded765f059a6e3036e69ca350449442af0fc","status":"affected","versionType":"git"},{"version":"63978ab3e3e963db28093b53bb4598f2702e1ad7","lessThan":"fd3a7bf0d988b0878a1957df150edb35f81db87e","status":"affected","versionType":"git"},{"version":"63978ab3e3e963db28093b53bb4598f2702e1ad7","lessThan":"eb0c7fda59cf650076f8ed5b949a6c8441aa3606","status":"affected","versionType":"git"},{"version":"63978ab3e3e963db28093b53bb4598f2702e1ad7","lessThan":"4294fe57048594a9e158b61c967bb7f943cda477","status":"affected","versionType":"git"},{"version":"63978ab3e3e963db28093b53bb4598f2702e1ad7","lessThan":"86f86e6fdedc33c5b8d38b9208b350f8accf57ee","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98741","source_modified_at":"2026-10-21T12:56:16.734Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"2.6.34","status":"affected"},{"version":"0","lessThan":"2.6.34","status":"unaffected","versionType":"semver"},{"version":"6.6.160","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.113","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.56","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.10","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98741","source_modified_at":"2026-10-21T12:56:16.734Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"4294fe57048594a9e158b61c967bb7f943cda477","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98741","source_modified_at":"2026-10-21T12:56:16.734Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"86f86e6fdedc33c5b8d38b9208b350f8accf57ee","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00168,"percentile":0.05735,"score_date":"2026-10-23"},"published_at":"2026-10-18T15:47:26.283Z","modified_at":"2026-10-21T12:56:16.734Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98741","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-21T12:56:16.734Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98741","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/ada5ded765f059a6e3036e69ca350449442af0fc"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/fd3a7bf0d988b0878a1957df150edb35f81db87e"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/eb0c7fda59cf650076f8ed5b949a6c8441aa3606"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/4294fe57048594a9e158b61c967bb7f943cda477"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/86f86e6fdedc33c5b8d38b9208b350f8accf57ee"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-21T12:56:16.734Z","content_hash":"4361443d32100fc8338a8afba1b1e3cd275aa34ae805bfc8417a0fbcaacc4dbe"}}