U.S. flag   An official website of the United States government
Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock (Dot gov) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

NOTICE UPDATED - April, 25th 2024

NIST has updated the NVD program announcement page with additional information regarding recent concerns and the temporary delays in enrichment efforts.

CVE-2021-47178 Detail

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: target: core: Avoid smp_processor_id() in preemptible code The BUG message "BUG: using smp_processor_id() in preemptible [00000000] code" was observed for TCMU devices with kernel config DEBUG_PREEMPT. The message was observed when blktests block/005 was run on TCMU devices with fileio backend or user:zbc backend [1]. The commit 1130b499b4a7 ("scsi: target: tcm_loop: Use LIO wq cmd submission helper") triggered the symptom. The commit modified work queue to handle commands and changed 'current->nr_cpu_allowed' at smp_processor_id() call. The message was also observed at system shutdown when TCMU devices were not cleaned up [2]. The function smp_processor_id() was called in SCSI host work queue for abort handling, and triggered the BUG message. This symptom was observed regardless of the commit 1130b499b4a7 ("scsi: target: tcm_loop: Use LIO wq cmd submission helper"). To avoid the preemptible code check at smp_processor_id(), get CPU ID with raw_smp_processor_id() instead. The CPU ID is used for performance improvement then thread move to other CPU will not affect the code. [1] [ 56.468103] run blktests block/005 at 2021-05-12 14:16:38 [ 57.369473] check_preemption_disabled: 85 callbacks suppressed [ 57.369480] BUG: using smp_processor_id() in preemptible [00000000] code: fio/1511 [ 57.369506] BUG: using smp_processor_id() in preemptible [00000000] code: fio/1510 [ 57.369512] BUG: using smp_processor_id() in preemptible [00000000] code: fio/1506 [ 57.369552] caller is __target_init_cmd+0x157/0x170 [target_core_mod] [ 57.369606] CPU: 4 PID: 1506 Comm: fio Not tainted 5.13.0-rc1+ #34 [ 57.369613] Hardware name: System manufacturer System Product Name/PRIME Z270-A, BIOS 1302 03/15/2018 [ 57.369617] Call Trace: [ 57.369621] BUG: using smp_processor_id() in preemptible [00000000] code: fio/1507 [ 57.369628] dump_stack+0x6d/0x89 [ 57.369642] check_preemption_disabled+0xc8/0xd0 [ 57.369628] caller is __target_init_cmd+0x157/0x170 [target_core_mod] [ 57.369655] __target_init_cmd+0x157/0x170 [target_core_mod] [ 57.369695] target_init_cmd+0x76/0x90 [target_core_mod] [ 57.369732] tcm_loop_queuecommand+0x109/0x210 [tcm_loop] [ 57.369744] scsi_queue_rq+0x38e/0xc40 [ 57.369761] __blk_mq_try_issue_directly+0x109/0x1c0 [ 57.369779] blk_mq_try_issue_directly+0x43/0x90 [ 57.369790] blk_mq_submit_bio+0x4e5/0x5d0 [ 57.369812] submit_bio_noacct+0x46e/0x4e0 [ 57.369830] __blkdev_direct_IO_simple+0x1a3/0x2d0 [ 57.369859] ? set_init_blocksize.isra.0+0x60/0x60 [ 57.369880] generic_file_read_iter+0x89/0x160 [ 57.369898] blkdev_read_iter+0x44/0x60 [ 57.369906] new_sync_read+0x102/0x170 [ 57.369929] vfs_read+0xd4/0x160 [ 57.369941] __x64_sys_pread64+0x6e/0xa0 [ 57.369946] ? lockdep_hardirqs_on+0x79/0x100 [ 57.369958] do_syscall_64+0x3a/0x70 [ 57.369965] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 57.369973] RIP: 0033:0x7f7ed4c1399f [ 57.369979] Code: 08 89 3c 24 48 89 4c 24 18 e8 7d f3 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 48 8b 74 24 08 8b 3c 24 b8 11 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 04 24 e8 cd f3 ff ff 48 8b [ 57.369983] RSP: 002b:00007ffd7918c580 EFLAGS: 00000293 ORIG_RAX: 0000000000000011 [ 57.369990] RAX: ffffffffffffffda RBX: 00000000015b4540 RCX: 00007f7ed4c1399f [ 57.369993] RDX: 0000000000001000 RSI: 00000000015de000 RDI: 0000000000000009 [ 57.369996] RBP: 00000000015b4540 R08: 0000000000000000 R09: 0000000000000001 [ 57.369999] R10: 0000000000e5c000 R11: 0000000000000293 R12: 00007f7eb5269a70 [ 57.370002] R13: 0000000000000000 R14: 0000000000001000 R15: 00000000015b4568 [ 57.370031] CPU: 7 PID: 1507 Comm: fio Not tainted 5.13.0-rc1+ #34 [ 57.370036] Hardware name: System manufacturer System Product Name/PRIME Z270-A, BIOS 1302 03/15/2018 [ 57.370039] Call Trace: [ 57.370045] dump_stack+0x6d/0x89 [ 57.370056] ch ---truncated---


Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  N/A
NVD assessment not yet provided.


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have not published a CVSS score for this CVE at this time. NVD Analysts use publicly available information at the time of analysis to associate CVSS vector strings.

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to nvd@nist.gov.

Hyperlink Resource
https://git.kernel.org/stable/c/70ca3c57ff914113f681e657634f7fbfa68e1ad1
https://git.kernel.org/stable/c/a20b6eaf4f35046a429cde57bee7eb5f13d6857f
https://git.kernel.org/stable/c/a222d2794c53f8165de20aa91b39e35e4b72bce9

Weakness Enumeration

CWE-ID CWE Name Source

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-47178
NVD Published Date:
03/25/2024
NVD Last Modified:
04/04/2024
Source:
kernel.org