Summary
The BPF subsystem in the Linux kernel before 4.17 mishandles
situations with a long jump over an instruction sequence where inner
instructions require substantial expansions into multiple BPF instructions,
leading to an overflow. This affects kernel/bpf/core.c and
net/core/filter.c.(CVE-2018-25020)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory.(CVE-2021-3653)
Nadav Amit discovered that the hugetlb implementation in the Linux kernel
did not perform TLB flushes under certain conditions. A local attacker
could use this to leak or alter data from other processes that use huge
pages.(CVE-2021-4002)
Andy Nguyen discovered that the netfilter subsystem in the Linux kernel
contained an out-of-bounds write in its setsockopt() implementation. A
local attacker could use this to cause a denial of service (system crash)
or possibly execute arbitrary code.(CVE-2021-22555)
It was discovered that the virtual file system implementation in the Linux
kernel contained an unsigned to signed integer conversion error. A local
attacker could use this to cause a denial of service (system crash) or
execute arbitrary code.(CVE-2021-33909)
Fixed packages 16
| Release | Package | Fixed in |
|---|---|---|
| Ubuntu · Pro 16.04 LTS Pro:16.04:LTS | linux | 4.4.0-218.251 |
| Ubuntu · Pro 16.04 LTS Pro:16.04:LTS | linux-aws | 4.4.0-1134.148 |
| Ubuntu · Pro 16.04 LTS Pro:16.04:LTS | linux-azure | 4.15.0-1129.142~16.04.1 |
| Ubuntu · Pro 16.04 LTS Pro:16.04:LTS | linux-hwe | 4.15.0-166.174~16.04.1 |
| Ubuntu · Pro 18.04 LTS Pro:18.04:LTS | linux | 4.15.0-166.174 |
| Ubuntu · Pro 18.04 LTS Pro:18.04:LTS | linux-aws | 4.15.0-1118.125 |
| Ubuntu · Pro 18.04 LTS Pro:18.04:LTS | linux-gke-4.15 | — |
| Ubuntu · Pro 18.04 LTS Pro:18.04:LTS | linux-gke-5.4 | 5.4.0-1057.60~18.04.1 |
| Ubuntu · Pro 18.04 LTS Pro:18.04:LTS | linux-gkeop-5.4 | 5.4.0-1029.30~18.04.2 |
| Ubuntu · Pro 18.04 LTS Pro:18.04:LTS | linux-oem | — |
| Ubuntu · Pro 20.04 LTS Pro:20.04:LTS | linux | 5.4.0-92.103 |
| Ubuntu · Pro 20.04 LTS Pro:20.04:LTS | linux-aws | 5.4.0-1061.64 |
| Ubuntu · Pro 20.04 LTS Pro:20.04:LTS | linux-azure | 5.4.0-1065.68 |
| Ubuntu · Pro 20.04 LTS Pro:20.04:LTS | linux-gcp | 5.4.0-1059.63 |
| Ubuntu · Pro 20.04 LTS Pro:20.04:LTS | linux-gke | 5.4.0-1057.60 |
| Ubuntu · Pro 20.04 LTS Pro:20.04:LTS | linux-gkeop | 5.4.0-1029.30 |
Vulnerabilities 5
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High 8.3
Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE
A heap out-of-bounds write affecting Linux since v2.6.19-rc1 was discovered in net/netfilter/x_tables.c. This allows an attacker to gain privileges or cause a DoS (via heap memory corruption) through user name space
KEV Oct 6, 2025 -
Unscored —
The BPF subsystem in the Linux kernel before 4.17 mishandles situations with a long jump over an instruction sequence w…
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Unscored —CVE-2021-33909 Public exploit
fs/seq_file.c in the Linux kernel 3.16 through 5.13.x before 5.13.4 does not properly restrict seq buffer allocations, …
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Unscored —
A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VM…
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Unscored —
A memory leak flaw in the Linux kernel's hugetlbfs memory usage was found in the way the user maps some regions of memo…