ALSA: 6fire: fix OOB write from device-reported iso length
In the Linux kernel, the following vulnerability has been resolved: ALSA: 6fire: fix OOB write from device-reported iso length usb6fire_pcm_in_urb_handler() sizes each outgoing isochronous packet as (actual_length - 4) / (in_n_analog << 2) * (out_n_analog << 2) + 4, where actual_length is the unsigned length the device reported for the matching IN packet. A packet completed with status 0 and actual_length < 4 wraps the subtraction to 0x7fffffec; a zero-length isochronous packet is legal on the bus, and the preceding loop rejects only non-zero status. The sum reaches memset() on out_urb->buffer, a 4832-byte object from kcalloc(PCM_MAX_PACKET_SIZE, PCM_N_PACKETS_PER_URB). Even without the wrap the result is out of bounds: at 88.2/96 kHz the 4-in/6-out scaling turns a full 420-byte IN packet into 628, so eight packets span 5024 bytes of that buffer. usb_submit_urb() rejects an over-long descriptor only after the memset() and the usb6fire_pcm_playback() copy of user PCM data have run. Guard the subtraction as the sibling usb6fire_pcm_capture() already does, and limit the frame count to what fits in rt->out_packet_size, the OUT endpoint's wMaxPacketSize. This bounds total_length by the buffer size while keeping each packet length aligned to a whole output frame. BUG: KASAN: out-of-bounds in usb6fire_pcm_in_urb_handler (sound/usb/6fire/pcm.c:338) Write of size 18446744073709551456 at addr ffff88802a3d0000 by task vhci_rx/5018 Call Trace: dump_stack_lvl (lib/dump_stack.c:94 lib/dump
CVE-2026-98312
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-2026-98312
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": "c6d43ba816d1cf1d125bfbfc938f2a28a87facf9",
"lessThan": "61e665fb48e9eee44ec6d610514af383b1802cc1",
"versionType": "git"
},
{
"status": "affected",
"version": "c6d43ba816d1cf1d125bfbfc938f2a28a87facf9",
"lessThan": "246de677552fe5dede293a1543b632e9853f31e4",
"versionType": "git"
},
{
"status": "affected",
"version": "c6d43ba816d1cf1d125bfbfc938f2a28a87facf9",
"lessThan": "001ba7c1d9677225a5ecbc3e60d4865c08bb21d8",
"versionType": "git"
},
{
"status": "affected",
"version": "c6d43ba816d1cf1d125bfbfc938f2a28a87facf9",
"lessThan": "ea11ade10583cc45af515d6b24510dbfa0184ca6",
"versionType": "git"
},
{
"status": "affected",
"version": "c6d43ba816d1cf1d125bfbfc938f2a28a87facf9",
"lessThan": "cdc31537012bc7a58c95c6750db321b69dd802bb",
"versionType": "git"
},
{
"status": "affected",
"version": "c6d43ba816d1cf1d125bfbfc938f2a28a87facf9",
"lessThan": "1589afe2d099d3e817873bc474676968d7080410",
"versionType": "git"
}
],
"programFiles": [
"sound/usb/6fire/pcm.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.39"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.39",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"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/6fire/pcm.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98312
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #38391 · Revision 1
- Added to Heist Feed
- Publisher date