{"id":"CVE-2026-98836","state":"PUBLISHED","title":"ALSA: line6: reject oversized playback packets","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: line6: reject oversized playback packets\n\nEach playback URB is handed a slice of out.buffer that is exactly\nLINE6_ISO_PACKETS * max_packet_size_out bytes, sized from the OUT\nendpoint, but the number of bytes written into that slice is never\ncompared against it.\n\nsubmit_audio_out_urb() takes the frame count from prev_fsize, which\naudio_in_callback() derived from the *IN* endpoint's received packet\nlength, and rescales it with the playback frame size; when prev_fsize is\nstill zero it synthesizes a length from the sample rate instead.  On a\ndevice declaring a large IN wMaxPacketSize and a small OUT\nwMaxPacketSize, the resulting memcpy(), or the memset() when the\nplayback stream is idle, runs past its slice and, as the reproducer\nbelow shows, beyond the allocation.\n\nusb_submit_urb() is not a backstop.  max_packet_size_out comes from\nusb_maxpacket(), which returns only the low 11 bits of wMaxPacketSize,\nwhile USB core validates a high-speed isochronous length against that\nbase scaled by usb_endpoint_maxp_mult().  A length of up to three times\nthe allocated slice is therefore accepted, and even a rejected URB is\nonly rejected after the write.\n\nReject a packet that does not fit the slice the driver allocated for it.\nClamping it instead would silently shorten the capture-derived rate\nfeedback and desynchronize the two streams.\n\n  BUG: KASAN: slab-out-of-bounds in submit_audio_out_urb (sound/usb/line6/playback.c:229)\n  Write of size 1024 at addr ffff888100bbd400 by task kworker/1:2/5002\n  Workqueue: events line6_startup_work\n  Call Trace:\n   __asan_memcpy (mm/kasan/shadow.c:106)\n   submit_audio_out_urb (sound/usb/line6/playback.c:229)\n   line6_submit_audio_out_all_urbs (sound/usb/line6/playback.c:291)\n   line6_stream_start (sound/usb/line6/pcm.c:194)\n   line6_pcm_acquire (sound/usb/line6/pcm.c:337)\n   line6_startup_work (sound/usb/line6/driver.c:728)\n   process_one_work (kernel/workqueue.c:3396)\n   worker_thread (kernel/workqueue.c:3479 kernel/workqueue.c:3560)\n   kthread (kernel/kthread.c:436)\n   ret_from_fork (arch/x86/kernel/process.c:158)\n   ret_from_fork_asm (arch/x86/entry/entry_64.S:245)\n\n  The buggy address belongs to the object at ffff888100bbd400\n   which belongs to the cache kmalloc-256 of size 256\n  The buggy address is located 0 bytes inside of\n   allocated 256-byte region [ffff888100bbd400, ffff888100bbd500)","publishedAt":"2026-10-18T15:49:51.823Z","updatedAt":"2026-10-30T12:40:05.522Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"48c76820dd8858ce60a6e42519141ebcf3dfeebf","versionType":"git"},{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"7f31587e26e1d4735924bc324e7fa506d85de150","versionType":"git"},{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"e3b68b1d92f279e203923dc8bf45c8860e5b5985","versionType":"git"},{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"933d8ac23388eb208ea195231d682dce0bec86ca","versionType":"git"},{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"a84371be89c39ccc46c7af8b9eb15c448df9265f","versionType":"git"},{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"3f75da1e4ee699f6650d23d6897cf443b01856c7","versionType":"git"},{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"b78748424f29f07d310484b2b36afdececa74389","versionType":"git"},{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"61b0a5a114fa4552892da5c0ff2f42e63bf08c6b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/line6/playback.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.9","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/line6/playback.c"]}],"references":["https://git.kernel.org/stable/c/48c76820dd8858ce60a6e42519141ebcf3dfeebf","https://git.kernel.org/stable/c/7f31587e26e1d4735924bc324e7fa506d85de150","https://git.kernel.org/stable/c/e3b68b1d92f279e203923dc8bf45c8860e5b5985","https://git.kernel.org/stable/c/933d8ac23388eb208ea195231d682dce0bec86ca","https://git.kernel.org/stable/c/a84371be89c39ccc46c7af8b9eb15c448df9265f","https://git.kernel.org/stable/c/3f75da1e4ee699f6650d23d6897cf443b01856c7","https://git.kernel.org/stable/c/b78748424f29f07d310484b2b36afdececa74389","https://git.kernel.org/stable/c/61b0a5a114fa4552892da5c0ff2f42e63bf08c6b"],"weaknesses":[],"ingestedAt":"2026-10-30T13:00:06.648Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98836.json","commit":"cb14bf1b43b0c9f05f7f40eae2246263fd430780","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98836","state":"PUBLISHED","datePublished":"2026-10-18T15:49:51.823Z","dateUpdated":"2026-10-30T12:40:05.522Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.372Z"},"containers":{"cna":{"title":"ALSA: line6: reject oversized playback packets","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: line6: reject oversized playback packets\n\nEach playback URB is handed a slice of out.buffer that is exactly\nLINE6_ISO_PACKETS * max_packet_size_out bytes, sized from the OUT\nendpoint, but the number of bytes written into that slice is never\ncompared against it.\n\nsubmit_audio_out_urb() takes the frame count from prev_fsize, which\naudio_in_callback() derived from the *IN* endpoint's received packet\nlength, and rescales it with the playback frame size; when prev_fsize is\nstill zero it synthesizes a length from the sample rate instead.  On a\ndevice declaring a large IN wMaxPacketSize and a small OUT\nwMaxPacketSize, the resulting memcpy(), or the memset() when the\nplayback stream is idle, runs past its slice and, as the reproducer\nbelow shows, beyond the allocation.\n\nusb_submit_urb() is not a backstop.  max_packet_size_out comes from\nusb_maxpacket(), which returns only the low 11 bits of wMaxPacketSize,\nwhile USB core validates a high-speed isochronous length against that\nbase scaled by usb_endpoint_maxp_mult().  A length of up to three times\nthe allocated slice is therefore accepted, and even a rejected URB is\nonly rejected after the write.\n\nReject a packet that does not fit the slice the driver allocated for it.\nClamping it instead would silently shorten the capture-derived rate\nfeedback and desynchronize the two streams.\n\n  BUG: KASAN: slab-out-of-bounds in submit_audio_out_urb (sound/usb/line6/playback.c:229)\n  Write of size 1024 at addr ffff888100bbd400 by task kworker/1:2/5002\n  Workqueue: events line6_startup_work\n  Call Trace:\n   __asan_memcpy (mm/kasan/shadow.c:106)\n   submit_audio_out_urb (sound/usb/line6/playback.c:229)\n   line6_submit_audio_out_all_urbs (sound/usb/line6/playback.c:291)\n   line6_stream_start (sound/usb/line6/pcm.c:194)\n   line6_pcm_acquire (sound/usb/line6/pcm.c:337)\n   line6_startup_work (sound/usb/line6/driver.c:728)\n   process_one_work (kernel/workqueue.c:3396)\n   worker_thread (kernel/workqueue.c:3479 kernel/workqueue.c:3560)\n   kthread (kernel/kthread.c:436)\n   ret_from_fork (arch/x86/kernel/process.c:158)\n   ret_from_fork_asm (arch/x86/entry/entry_64.S:245)\n\n  The buggy address belongs to the object at ffff888100bbd400\n   which belongs to the cache kmalloc-256 of size 256\n  The buggy address is located 0 bytes inside of\n   allocated 256-byte region [ffff888100bbd400, ffff888100bbd500)"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"48c76820dd8858ce60a6e42519141ebcf3dfeebf","versionType":"git"},{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"7f31587e26e1d4735924bc324e7fa506d85de150","versionType":"git"},{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"e3b68b1d92f279e203923dc8bf45c8860e5b5985","versionType":"git"},{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"933d8ac23388eb208ea195231d682dce0bec86ca","versionType":"git"},{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"a84371be89c39ccc46c7af8b9eb15c448df9265f","versionType":"git"},{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"3f75da1e4ee699f6650d23d6897cf443b01856c7","versionType":"git"},{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"b78748424f29f07d310484b2b36afdececa74389","versionType":"git"},{"version":"7a0f55aeeb8f1fa32a119d34ddfefc6100936692","status":"affected","lessThan":"61b0a5a114fa4552892da5c0ff2f42e63bf08c6b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/line6/playback.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.9","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/line6/playback.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/48c76820dd8858ce60a6e42519141ebcf3dfeebf"},{"url":"https://git.kernel.org/stable/c/7f31587e26e1d4735924bc324e7fa506d85de150"},{"url":"https://git.kernel.org/stable/c/e3b68b1d92f279e203923dc8bf45c8860e5b5985"},{"url":"https://git.kernel.org/stable/c/933d8ac23388eb208ea195231d682dce0bec86ca"},{"url":"https://git.kernel.org/stable/c/a84371be89c39ccc46c7af8b9eb15c448df9265f"},{"url":"https://git.kernel.org/stable/c/3f75da1e4ee699f6650d23d6897cf443b01856c7"},{"url":"https://git.kernel.org/stable/c/b78748424f29f07d310484b2b36afdececa74389"},{"url":"https://git.kernel.org/stable/c/61b0a5a114fa4552892da5c0ff2f42e63bf08c6b"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:40:05.522Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"6.12.113"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"6.18.56"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"7.2.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}