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CVE-2021-47552— blk-mq: cancel blk-mq dispatch work in both blk_cleanup_queue and disk_release()

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于blk_cleanup_queue和disk_release()中的blk-mq调度工作存在安全漏洞。

CVSS 7.8 · High EPSS 0.21% · P11

Possible ATT&CK Techniques 1 AI

T1499 · Endpoint Denial of Service

Affected Version Matrix 6

VendorProduct Version RangeStatus
Linux Linux 1b97871b501f1bac0fd39a073c4c8473ee457a55< e03513f58919d9e2bc6df765ca2c9da863d03d90 affected
1b97871b501f1bac0fd39a073c4c8473ee457a55< 2a19b28f7929866e1cec92a3619f4de9f2d20005 affected
5.2 affected
< 5.2 unaffected
5.15.6≤ 5.15.* unaffected
5.16≤ * unaffected
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I. Basic Information for CVE-2021-47552

Vulnerability Information
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Vulnerability Title
blk-mq: cancel blk-mq dispatch work in both blk_cleanup_queue and disk_release()
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: blk-mq: cancel blk-mq dispatch work in both blk_cleanup_queue and disk_release() For avoiding to slow down queue destroy, we don't call blk_mq_quiesce_queue() in blk_cleanup_queue(), instead of delaying to cancel dispatch work in blk_release_queue(). However, this way has caused kernel oops[1], reported by Changhui. The log shows that scsi_device can be freed before running blk_release_queue(), which is expected too since scsi_device is released after the scsi disk is closed and the scsi_device is removed. Fixes the issue by canceling blk-mq dispatch work in both blk_cleanup_queue() and disk_release(): 1) when disk_release() is run, the disk has been closed, and any sync dispatch activities have been done, so canceling dispatch work is enough to quiesce filesystem I/O dispatch activity. 2) in blk_cleanup_queue(), we only focus on passthrough request, and passthrough request is always explicitly allocated & freed by its caller, so once queue is frozen, all sync dispatch activity for passthrough request has been done, then it is enough to just cancel dispatch work for avoiding any dispatch activity. [1] kernel panic log [12622.769416] BUG: kernel NULL pointer dereference, address: 0000000000000300 [12622.777186] #PF: supervisor read access in kernel mode [12622.782918] #PF: error_code(0x0000) - not-present page [12622.788649] PGD 0 P4D 0 [12622.791474] Oops: 0000 [#1] PREEMPT SMP PTI [12622.796138] CPU: 10 PID: 744 Comm: kworker/10:1H Kdump: loaded Not tainted 5.15.0+ #1 [12622.804877] Hardware name: Dell Inc. PowerEdge R730/0H21J3, BIOS 1.5.4 10/002/2015 [12622.813321] Workqueue: kblockd blk_mq_run_work_fn [12622.818572] RIP: 0010:sbitmap_get+0x75/0x190 [12622.823336] Code: 85 80 00 00 00 41 8b 57 08 85 d2 0f 84 b1 00 00 00 45 31 e4 48 63 cd 48 8d 1c 49 48 c1 e3 06 49 03 5f 10 4c 8d 6b 40 83 f0 01 <48> 8b 33 44 89 f2 4c 89 ef 0f b6 c8 e8 fa f3 ff ff 83 f8 ff 75 58 [12622.844290] RSP: 0018:ffffb00a446dbd40 EFLAGS: 00010202 [12622.850120] RAX: 0000000000000001 RBX: 0000000000000300 RCX: 0000000000000004 [12622.858082] RDX: 0000000000000006 RSI: 0000000000000082 RDI: ffffa0b7a2dfe030 [12622.866042] RBP: 0000000000000004 R08: 0000000000000001 R09: ffffa0b742721334 [12622.874003] R10: 0000000000000008 R11: 0000000000000008 R12: 0000000000000000 [12622.881964] R13: 0000000000000340 R14: 0000000000000000 R15: ffffa0b7a2dfe030 [12622.889926] FS: 0000000000000000(0000) GS:ffffa0baafb40000(0000) knlGS:0000000000000000 [12622.898956] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [12622.905367] CR2: 0000000000000300 CR3: 0000000641210001 CR4: 00000000001706e0 [12622.913328] Call Trace: [12622.916055] <TASK> [12622.918394] scsi_mq_get_budget+0x1a/0x110 [12622.922969] __blk_mq_do_dispatch_sched+0x1d4/0x320 [12622.928404] ? pick_next_task_fair+0x39/0x390 [12622.933268] __blk_mq_sched_dispatch_requests+0xf4/0x140 [12622.939194] blk_mq_sched_dispatch_requests+0x30/0x60 [12622.944829] __blk_mq_run_hw_queue+0x30/0xa0 [12622.949593] process_one_work+0x1e8/0x3c0 [12622.954059] worker_thread+0x50/0x3b0 [12622.958144] ? rescuer_thread+0x370/0x370 [12622.962616] kthread+0x158/0x180 [12622.966218] ? set_kthread_struct+0x40/0x40 [12622.970884] ret_from_fork+0x22/0x30 [12622.974875] </TASK> [12622.977309] Modules linked in: scsi_debug rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs sunrpc dm_multipath intel_rapl_msr intel_rapl_common dell_wmi_descriptor sb_edac rfkill video x86_pkg_temp_thermal intel_powerclamp dcdbas coretemp kvm_intel kvm mgag200 irqbypass i2c_algo_bit rapl drm_kms_helper ipmi_ssif intel_cstate intel_uncore syscopyarea sysfillrect sysimgblt fb_sys_fops pcspkr cec mei_me lpc_ich mei ipmi_si ipmi_devintf ipmi_msghandler acpi_power_meter drm fuse xfs libcrc32c sr_mod cdrom sd_mod t10_pi sg ixgbe ahci libahci crct10dif_pclmul crc32_pclmul crc32c_intel libata megaraid_sas ghash_clmulni_intel tg3 wdat_w ---truncated---
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于blk_cleanup_queue和disk_release()中的blk-mq调度工作存在安全漏洞。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux 1b97871b501f1bac0fd39a073c4c8473ee457a55 ~ e03513f58919d9e2bc6df765ca2c9da863d03d90 -
Linux Linux 5.2 -

II. Public POCs for CVE-2021-47552

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III. Intelligence Information for CVE-2021-47552

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Other References for CVE-2021-47552 (2)

Same Patch Batch · Linux · 2024-05-24 · 72 CVEs total

CVE-2021-47544 9.8 CRITICAL tcp: fix page frag corruption on page fault
CVE-2021-47506 9.8 CRITICAL nfsd: fix use-after-free due to delegation race
CVE-2021-47536 9.8 CRITICAL net/smc: fix wrong list_del in smc_lgr_cleanup_early
CVE-2021-47520 8.8 HIGH can: pch_can: pch_can_rx_normal: fix use after free
CVE-2023-52880 7.8 HIGH tty: n_gsm: require CAP_NET_ADMIN to attach N_GSM0710 ldisc
CVE-2021-47512 7.8 HIGH net/sched: fq_pie: prevent dismantle issue
CVE-2021-47502 7.8 HIGH ASoC: codecs: wcd934x: handle channel mappping list correctly
CVE-2021-47505 7.8 HIGH aio: fix use-after-free due to missing POLLFREE handling
CVE-2021-47517 7.8 HIGH ethtool: do not perform operations on net devices being unregistered
CVE-2021-47533 7.8 HIGH drm/vc4: kms: Clear the HVS FIFO commit pointer once done
CVE-2021-47500 7.8 HIGH iio: mma8452: Fix trigger reference couting
CVE-2021-47541 7.8 HIGH net/mlx4_en: Fix an use-after-free bug in mlx4_en_try_alloc_resources()
CVE-2021-47551 7.8 HIGH drm/amd/amdkfd: Fix kernel panic when reset failed and been triggered again
CVE-2021-47555 7.8 HIGH net: vlan: fix underflow for the real_dev refcnt
CVE-2021-47561 7.8 HIGH i2c: virtio: disable timeout handling
CVE-2021-47535 7.8 HIGH drm/msm/a6xx: Allocate enough space for GMU registers
CVE-2021-47515 7.5 HIGH seg6: fix the iif in the IPv6 socket control block
CVE-2021-47559 7.5 HIGH net/smc: Fix NULL pointer dereferencing in smc_vlan_by_tcpsk()
CVE-2021-47553 sched/scs: Reset task stack state in bringup_cpu()
CVE-2021-47513 net: dsa: felix: Fix memory leak in felix_setup_mmio_filtering

Showing top 20 of 72 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2021-47552

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