Out-of-Bounds Write in Linux kernel (CVE-2021-47580)
Summary
Out-of-bounds write in Linux kernel (CVE-2021-47580). Confidential information can be exposed externally.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
scsi: scsi_debug: Fix type in min_t to avoid stack OOB
Change min_t() to use type "u32" instead of type "int" to avoid stack out
of bounds. With min_t() type "int" the values get sign extended and the
larger value gets used causing stack out of bounds.
BUG: KASAN: stack-out-of-bounds in memcpy include/linux/fortify-string.h:191 [inline]
BUG: KASAN: stack-out-of-bounds in sg_copy_buffer+0x1de/0x240 lib/scatterlist.c:976
Read of size 127 at addr ffff888072607128 by task syz-executor.7/18707
CPU: 1 PID: 18707 Comm: syz-executor.7 Not tainted 5.15.0-syzk #1
Hardware name: Red Hat KVM, BIOS 1.13.0-2
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x89/0xb5 lib/dump_stack.c:106
print_address_description.constprop.9+0x28/0x160 mm/kasan/report.c:256
__kasan_report mm/kasan/report.c:442 [inline]
kasan_report.cold.14+0x7d/0x117 mm/kasan/report.c:459
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x1a3/0x210 mm/kasan/generic.c:189
memcpy+0x23/0x60 mm/kasan/shadow.c:65
memcpy include/linux/fortify-string.h:191 [inline]
sg_copy_buffer+0x1de/0x240 lib/scatterlist.c:976
sg_copy_from_buffer+0x33/0x40 lib/scatterlist.c:1000
fill_from_dev_buffer.part.34+0x82/0x130 drivers/scsi/scsi_debug.c:1162
fill_from_dev_buffer drivers/scsi/scsi_debug.c:1888 [inline]
resp_readcap16+0x365/0x3b0 drivers/scsi/scsi_debug.c:1887
schedule_resp+0x4d8/0x1a70 drivers/scsi/scsi_debug.c:5…
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2021-47580 has been found in Linux kernel.
Confidential information can be exposed externally. CVSS score: 7.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2021-47580" on the vendor's site.
CVE-2021-47580 (Linux kernel) — CWE-787 / CVSS v3 7.1
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Out-of-bounds write (CWE-787) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: High (CVSS 7.1/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2021-47580 linux Fixed in: 5.15.15-1
- Ubuntu UBUNTU-CVE-2021-47580 linux
References
- patch git.kernel.org
- patch git.kernel.org
- patch git.kernel.org