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CVE-2021-47111— xen-netback: take a reference to the RX task thread

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 xen-netback 模块中存在错误。

CVSS 8.8 · High EPSS 0.24% · P13

Possible ATT&CK Techniques 1 AI

T1211 · Exploitation for Stealth

Affected Version Matrix 8

VendorProduct Version RangeStatus
Linux Linux 2ac061ce97f413bfbbdd768f7d2e0fda2e8170df< 6b53db8c4c14b4e7256f058d202908b54a7b85b4 affected
2ac061ce97f413bfbbdd768f7d2e0fda2e8170df< caec9bcaeb1a5f03f2d406305355c853af10c13e affected
2ac061ce97f413bfbbdd768f7d2e0fda2e8170df< 107866a8eb0b664675a260f1ba0655010fac1e08 affected
5.5 affected
< 5.5 unaffected
5.10.43≤ 5.10.* unaffected
5.12.10≤ 5.12.* unaffected
5.13≤ * unaffected
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I. Basic Information for CVE-2021-47111

Vulnerability Information
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Vulnerability Title
xen-netback: take a reference to the RX task thread
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: xen-netback: take a reference to the RX task thread Do this in order to prevent the task from being freed if the thread returns (which can be triggered by the frontend) before the call to kthread_stop done as part of the backend tear down. Not taking the reference will lead to a use-after-free in that scenario. Such reference was taken before but dropped as part of the rework done in 2ac061ce97f4. Reintroduce the reference taking and add a comment this time explaining why it's needed. This is XSA-374 / CVE-2021-28691.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/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 xen-netback 模块中存在错误。
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 2ac061ce97f413bfbbdd768f7d2e0fda2e8170df ~ 6b53db8c4c14b4e7256f058d202908b54a7b85b4 -
Linux Linux 5.5 -

II. Public POCs for CVE-2021-47111

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III. Intelligence Information for CVE-2021-47111

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Other References for CVE-2021-47111 (3)

Same Patch Batch · Linux · 2024-03-15 · 26 CVEs total

CVE-2021-47131 8.1 HIGH net/tls: Fix use-after-free after the TLS device goes down and up
CVE-2021-47123 7.8 HIGH io_uring: fix ltout double free on completion race
CVE-2021-47135 7.8 HIGH mt76: mt7921: fix possible AOOB issue in mt7921_mcu_tx_rate_report
CVE-2021-47129 7.8 HIGH netfilter: nft_ct: skip expectations for confirmed conntrack
CVE-2021-47126 7.8 HIGH ipv6: Fix KASAN: slab-out-of-bounds Read in fib6_nh_flush_exceptions
CVE-2021-47124 7.8 HIGH io_uring: fix link timeout refs
CVE-2021-47112 7.8 HIGH x86/kvm: Teardown PV features on boot CPU as well
CVE-2021-47132 7.5 HIGH mptcp: fix sk_forward_memory corruption on retransmission
CVE-2021-47109 7.5 HIGH neighbour: allow NUD_NOARP entries to be forced GCed
CVE-2021-47130 7.5 HIGH nvmet: fix freeing unallocated p2pmem
CVE-2021-47113 7.1 HIGH btrfs: abort in rename_exchange if we fail to insert the second ref
CVE-2021-47114 ocfs2: fix data corruption by fallocate
CVE-2021-47110 x86/kvm: Disable kvmclock on all CPUs on shutdown
CVE-2021-47134 efi/fdt: fix panic when no valid fdt found
CVE-2021-47133 HID: amd_sfh: Fix memory leak in amd_sfh_work
CVE-2021-47128 bpf, lockdown, audit: Fix buggy SELinux lockdown permission checks
CVE-2021-47127 ice: track AF_XDP ZC enabled queues in bitmap
CVE-2021-47117 ext4: fix bug on in ext4_es_cache_extent as ext4_split_extent_at failed
CVE-2021-47125 sch_htb: fix refcount leak in htb_parent_to_leaf_offload
CVE-2021-47116 ext4: fix memory leak in ext4_mb_init_backend on error path.

Showing top 20 of 26 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2021-47111

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