{"affected":[{"defaultStatus":"unaffected","product":"Linux","source":"CNA: Linux","vendor":"Linux","versions":[{"lessThan":"862d9268f40a6e10cef24eb226e738fb69ce8aa7","status":"affected","version":"63e20df1e5b2ef8d871ecbdb6c038d554ed1ca74","versionType":"git"},{"lessThan":"22c82f33ff0b68d37041adf1dea5533a5863cd31","status":"affected","version":"63e20df1e5b2ef8d871ecbdb6c038d554ed1ca74","versionType":"git"},{"lessThan":"aa118c8f61d59387961d58ffae831c5259a9f222","status":"affected","version":"63e20df1e5b2ef8d871ecbdb6c038d554ed1ca74","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","source":"CNA: Linux","vendor":"Linux","versions":[{"status":"affected","version":"4.0"},{"lessThan":"4.0","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.61","versionType":"semver"},{"lessThanOrEqual":"7.3.*","status":"unaffected","version":"7.3.2","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.4-rc1","versionType":"original_commit_for_fix"}]}],"cveId":"CVE-2026-99271","cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: line6: Clear prev_fbuf on capture buffer release\n\nA KASAN slab-use-after-free read was reported in submit_audio_out_urb()\nwhen generating an impulse test signal:\n\n  BUG: KASAN: slab-use-after-free in create_impulse_test_signal sound/usb/line6/playback.c:76 [inline]\n  BUG: KASAN: slab-use-after-free in submit_audio_out_urb+0x1848/0x1b20 sound/usb/line6/playback.c:249\n  Read of size 2 at addr ffff888008d74870 by task syz.2.3214/7785\n\n  Allocated by task 11:\n   kmem_cache_alloc_noprof+0x2f0/0x390 mm/slub.c:4144\n   line6_buffer_acquire+0x1a1/0x220 sound/usb/line6/pcm.c:158\n   line6_pcm_acquire+0xb6/0x230 sound/usb/line6/pcm.c:329\n   line6_startup_work+0x3c/0x50 sound/usb/line6/driver.c:728\n\n  Freed by task 7785:\n   kfree+0xf8/0x390 mm/slub.c:6566\n   line6_buffer_release sound/usb/line6/pcm.c:176 [inline]\n   line6_buffer_release+0xa5/0xf0 sound/usb/line6/pcm.c:170\n   __line6_pcm_release sound/usb/line6/pcm.c:305 [inline]\n   line6_pcm_release+0x5a/0x80 sound/usb/line6/pcm.c:313\n   snd_toneport_monitor_put+0x11b/0x190 sound/usb/line6/toneport.c:183\n\nline6pcm->prev_fbuf points into the capture PCM stream buffer\n(line6pcm->in.buffer), which is updated during audio_in_callback() to\nfeed rate synchronization, software monitoring, and impulse test signal\ngeneration on playback side.\n\nWhen all capture streams are closed, line6_buffer_release() frees\npstr->buffer with kfree().  However, it does not clear line6pcm->prev_fbuf.\nIf playback is subsequently started (e.g. via impulse test signal\nvolume control snd_line6_impulse_volume_put()), submit_audio_out_urb()\ndereferences the stale pointer line6pcm->prev_fbuf under in.lock,\nresulting in a slab-use-after-free read.\n\nClear prev_fbuf and prev_fsize in line6_buffer_release() when releasing\nthe capture stream buffer under in.lock, ensuring that no stale buffer\npointer can be accessed by submit_audio_out_urb().","epss":null,"exploits":[],"kev":null,"metrics":[],"modifiedAt":1794060525047,"publishedAt":1794060525047,"references":[{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/862d9268f40a6e10cef24eb226e738fb69ce8aa7"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/22c82f33ff0b68d37041adf1dea5533a5863cd31"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/aa118c8f61d59387961d58ffae831c5259a9f222"}],"remediation":[],"revision":"60d12b01b15be6b4c9152c08c13423da06a4b95e3b034eb61938b9d326649e1a","sources":[{"modifiedAt":1794060525047,"name":"CNA: Linux","retrievedAt":1794064149650,"url":"https://www.cve.org/CVERecord?id=CVE-2026-99271"}],"ssvc":null,"status":"published","title":"ALSA: line6: Clear prev_fbuf on capture buffer release","updatedAt":1794064149650}