Vulnerability Description
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_core_mod] ? target_check_fua+0x40/0x40 [target_core_mod] ? transport_complete_task_attr+0x130/0x130 [target_core_mod] target_xcopy_do_work+0x61f/0xc00 [target_core_mod] This fix makes target_complete_cmd() queue work on se_cmd->cpuid if se_tpg_wwn is NULL.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 5.13, < 5.13.6 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/a47fa41381a09e5997afd762664db4f5f6657e03Patch
- https://git.kernel.org/stable/c/e7732c5a19a15a62b0b23fd683a639b0483e1f40Patch
- https://git.kernel.org/stable/c/a47fa41381a09e5997afd762664db4f5f6657e03Patch
- https://git.kernel.org/stable/c/e7732c5a19a15a62b0b23fd683a639b0483e1f40Patch
FAQ
What is CVE-2021-47290?
CVE-2021-47290 is a vulnerability with a CVSS score of 5.5 (MEDIUM). 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: M...
How severe is CVE-2021-47290?
CVE-2021-47290 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-47290?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.