ALSA: usb-audio: Clamp implicit feedback packet count to URB capacity
In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Clamp implicit feedback packet count to URB capacity data_ep_set_params() allocates each data URB for exactly u->packets isochronous frames, so urb->iso_frame_desc[] has u->packets slots and ctx->packets is the driver's only record of that limit. For an implicit feedback sink, snd_usb_queue_pending_output_urbs() overwrites it with the sync source's packet count, which is calculated independently from the capture endpoint's parameters. When that count is larger, prepare_playback_urb() and prepare_silent_urb() can write iso_frame_desc[] past the allocation; their existing bounds limit payload bytes, not the descriptor index. The reproducer uses a high-speed UAC2 device declaring bInterval 1 for implicit feedback capture (8 packets) and bInterval 4 for playback (1 packet). On the first capture completion after the stream starts, it accesses seven descriptors spanning 112 bytes beyond the one-packet URB: BUG: KASAN: slab-out-of-bounds in prepare_playback_urb (sound/usb/pcm.c:1560) Write of size 4 at addr ffff88801e696ad0 by task vhci_rx/178 prepare_playback_urb (sound/usb/pcm.c:1560) prepare_outbound_urb (sound/usb/endpoint.c:340) snd_usb_queue_pending_output_urbs (sound/usb/endpoint.c:501) snd_complete_urb (sound/usb/endpoint.c:1834) __usb_hcd_giveback_urb (drivers/usb/core/hcd.c:1657) usb_hcd_giveback_urb (drivers/usb/core/hcd.c:1741) vhci_rx_loop (drivers/usb/usbip/vhci_rx.c:107) kthread (kern
CVE-2026-98265
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-98265
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "c26bde6301f20d9aafbfb7c2459a88c6a6ec178f",
"lessThan": "8b637ab10e40e01b452f4aff66dad335a9b89a16",
"versionType": "git"
},
{
"status": "affected",
"version": "32a1f64f8ff6e2c5391f5964baec697bce25b83c",
"lessThan": "ad279ba0dc1781229f5b52f58d38d56960400e06",
"versionType": "git"
},
{
"status": "affected",
"version": "e949fd266cfa1dcca7caa3faa698578c4ffd26d6",
"lessThan": "79c55a7b5d71cf2a6bbd4bd7698e1b10b70f813a",
"versionType": "git"
},
{
"status": "affected",
"version": "cf044e44190234a41a788de1cdbb6c21f4a52e1e",
"lessThan": "ab77e3f453c5f2499c08d6e8e218501d25bab39e",
"versionType": "git"
},
{
"status": "affected",
"version": "cf044e44190234a41a788de1cdbb6c21f4a52e1e",
"lessThan": "76a986c980bb502c7688d605ac7a67fd257a9a1b",
"versionType": "git"
},
{
"status": "affected",
"version": "df75696e70c88b22ed1d8c9d515993a858c58fd0",
"versionType": "git"
},
{
"status": "affected",
"version": "3a74f6b46c01d9a816378cd83c327a59f61475ec",
"versionType": "git"
},
{
"status": "affected",
"version": "f6fbdf797e016fbf968dd54301026b182175985a",
"versionType": "git"
},
{
"status": "affected",
"version": "6.6.128",
"lessThan": "6.6.160",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.12.75",
"lessThan": "6.12.112",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.18.16",
"lessThan": "6.18.54",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.15.202",
"lessThan": "5.16",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.1.165",
"lessThan": "6.2",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.19.6",
"lessThan": "6.20",
"versionType": "semver"
}
],
"programFiles": [
"sound/usb/card.h",
"sound/usb/endpoint.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "7.0"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "7.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.54",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.8",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"sound/usb/card.h",
"sound/usb/endpoint.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98265
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #48874 · Revision 1
- Added to Heist Feed
- Publisher date