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CVE-2021-47223— net: bridge: fix vlan tunnel dst null pointer dereference

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，该漏洞源于存在空指针取消引用。

AI Predicted 6.5 Difficulty: Moderate EPSS 0.24% · P14

Possible ATT&CK Techniques 1 AI

T1068 · Exploitation for Privilege Escalation

Affected Version Matrix 14

VendorProduct Version RangeStatus
Linux Linux 11538d039ac6efcf4f1a6c536e1b87cd3668a9fd< ad7feefe7164892db424c45687472db803d87f79 affected
11538d039ac6efcf4f1a6c536e1b87cd3668a9fd< 24a6e55f17aa123bc1fc54b7d3c410b41bc16530 affected
11538d039ac6efcf4f1a6c536e1b87cd3668a9fd< a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c affected
11538d039ac6efcf4f1a6c536e1b87cd3668a9fd< fe0448a3fad365a747283a00a1d1ad5e8d6675b7 affected
11538d039ac6efcf4f1a6c536e1b87cd3668a9fd< abb02e05cb1c0a30dd873a29f33bc092067dc35d affected
11538d039ac6efcf4f1a6c536e1b87cd3668a9fd< 58e2071742e38f29f051b709a5cca014ba51166f affected
4.11 affected
< 4.11 unaffected
… +6 more rows
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I. Basic Information for CVE-2021-47223

Vulnerability Information
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Vulnerability Title
net: bridge: fix vlan tunnel dst null pointer dereference
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: net: bridge: fix vlan tunnel dst null pointer dereference This patch fixes a tunnel_dst null pointer dereference due to lockless access in the tunnel egress path. When deleting a vlan tunnel the tunnel_dst pointer is set to NULL without waiting a grace period (i.e. while it's still usable) and packets egressing are dereferencing it without checking. Use READ/WRITE_ONCE to annotate the lockless use of tunnel_id, use RCU for accessing tunnel_dst and make sure it is read only once and checked in the egress path. The dst is already properly RCU protected so we don't need to do anything fancy than to make sure tunnel_id and tunnel_dst are read only once and checked in the egress path.
Source: CVE Program / CVE List V5
CVSS Information
N/A
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，该漏洞源于存在空指针取消引用。
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 11538d039ac6efcf4f1a6c536e1b87cd3668a9fd ~ ad7feefe7164892db424c45687472db803d87f79 -
Linux Linux 4.11 -

II. Public POCs for CVE-2021-47223

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III. Intelligence Information for CVE-2021-47223

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Other References for CVE-2021-47223 (6)

Same Patch Batch · Linux · 2024-05-21 · 361 CVEs total

CVE-2023-52741 9.8 CRITICAL cifs: Fix use-after-free in rdata->read_into_pages()
CVE-2023-52755 9.8 CRITICAL ksmbd: fix slab out of bounds write in smb_inherit_dacl()
CVE-2021-47378 9.8 CRITICAL nvme-rdma: destroy cm id before destroy qp to avoid use after free
CVE-2021-47427 9.8 CRITICAL scsi: iscsi: Fix iscsi_task use after free
CVE-2023-52732 9.8 CRITICAL ceph: blocklist the kclient when receiving corrupted snap trace
CVE-2021-47232 9.8 CRITICAL can: j1939: fix Use-after-Free, hold skb ref while in use
CVE-2021-47328 9.8 CRITICAL scsi: iscsi: Fix conn use after free during resets
CVE-2023-52769 8.8 HIGH wifi: ath12k: fix htt mlo-offset event locking
CVE-2023-52790 8.8 HIGH swiotlb: fix out-of-bounds TLB allocations with CONFIG_SWIOTLB_DYNAMIC
CVE-2021-47308 8.8 HIGH scsi: libfc: Fix array index out of bound exception
CVE-2021-47390 8.8 HIGH KVM: x86: Fix stack-out-of-bounds memory access from ioapic_write_indirect()
CVE-2023-52798 8.8 HIGH wifi: ath11k: fix dfs radar event locking
CVE-2021-47388 8.8 HIGH mac80211: fix use-after-free in CCMP/GCMP RX
CVE-2023-52776 8.8 HIGH wifi: ath12k: fix dfs-radar and temperature event locking
CVE-2023-52801 8.8 HIGH iommufd: Fix missing update of domains_itree after splitting iopt_area
CVE-2023-52846 8.8 HIGH hsr: Prevent use after free in prp_create_tagged_frame()
CVE-2021-47352 8.4 HIGH virtio-net: Add validation for used length
CVE-2023-52829 8.4 HIGH wifi: ath12k: fix possible out-of-bound write in ath12k_wmi_ext_hal_reg_caps()
CVE-2021-47240 8.4 HIGH net: qrtr: fix OOB Read in qrtr_endpoint_post
CVE-2021-47244 8.2 HIGH mptcp: Fix out of bounds when parsing TCP options

Showing top 20 of 361 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2021-47223

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