CVE intelligence and bounded remediation

CVE-2021-47290 — Linux Linux Kernel security vulnerability

Medium CVSS 5.5

In the Linux kernel, the following vulnerability has been resolved: scsi: target: Fix NULL dereference on XCOPY completion CPU affinity control added with commit 39ae3edda325 ("scsi: target: core: Make completion affinity configurable") makes target_complete_cmd() queue work on a CPU based on se_tpg->se_tpg_wwn->cmd_compl_affinity state. LIO's EXTENDED COPY worker is a special case in that read/write cmds are dispatched using the global xcopy_pt_tpg, which carries a NULL se_tpg_wwn pointer following initialization in target_xcopy_setup_pt(). The NULL xcopy_pt_tpg->se_tpg_wwn pointer is dereferenced on completion of any EXTENDED COPY initiated read/write cmds. E.g using the libiscsi SCSI.ExtendedCopy.Simple test: BUG: kernel NULL pointer dereference, address: 00000000000001a8 RIP: 0010:target_complete_cmd+0x9d/0x130 [target_core_mod] Call Trace: fd_execute_rw+0x148/0x42a [target_core_file] ? __dynamic_pr_debug+0xa7/0xe0 ? target_check_reservation+0x5b/0x940 [target_core_mod] __target_execute_cmd+0x1e/0x90 [target_core_mod] transport_generic_new_cmd+0x17c/0x330 [target_core_mod] target_xcopy_issue_pt_cmd+0x9/0x60 [target_core_mod] target_xcopy_read_source.isra.7+0x10b/0x1b0 [target_…

Severity
Medium
CVSS
5.5 (3.1)
Published
2024-05-21
CISA KEV
Not currently listed
Ecosystem
linux/kernel
Weaknesses
CWE-476

Affected products

  • linux / linux_kernel
  • linux / linux_kernel / 5.14

Showing 2 representative product identities from 3 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

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Check exposure

  • Identify affected native-code versions, build flags, architectures, parsers, codecs, drivers, and input paths in all shipped artifacts.
  • Determine whether untrusted data reaches the affected routine and the process privilege, sandbox, and network exposure.
  • Confirm statically linked, vendored, firmware, and platform-provided copies, not only package-manager records.

Remediate safely

  • Apply the maintained upstream correction or replace the affected component, then rebuild every dependent artifact from clean inputs.
  • Adopt bounds-checked interfaces, validated sizes and integer conversions, clear ownership, and memory-safe components where practical.
  • Enable supported compiler and runtime hardening and add sanitized tests and fuzz regression seeds derived from non-weaponized fixtures.

Authoritative sources

Complete CVE record and remediation plan

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