CVE-2021-47376

MEDIUM

Linux Kernel - Denial of Service via Oversized kvcalloc() in BPF Verifier

Title source: llm
STIX 2.1

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Add oversize check before call kvcalloc() Commit 7661809d493b ("mm: don't allow oversized kvmalloc() calls") add the oversize check. When the allocation is larger than what kmalloc() supports, the following warning triggered: WARNING: CPU: 0 PID: 8408 at mm/util.c:597 kvmalloc_node+0x108/0x110 mm/util.c:597 Modules linked in: CPU: 0 PID: 8408 Comm: syz-executor221 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kvmalloc_node+0x108/0x110 mm/util.c:597 Call Trace: kvmalloc include/linux/mm.h:806 [inline] kvmalloc_array include/linux/mm.h:824 [inline] kvcalloc include/linux/mm.h:829 [inline] check_btf_line kernel/bpf/verifier.c:9925 [inline] check_btf_info kernel/bpf/verifier.c:10049 [inline] bpf_check+0xd634/0x150d0 kernel/bpf/verifier.c:13759 bpf_prog_load kernel/bpf/syscall.c:2301 [inline] __sys_bpf+0x11181/0x126e0 kernel/bpf/syscall.c:4587 __do_sys_bpf kernel/bpf/syscall.c:4691 [inline] __se_sys_bpf kernel/bpf/syscall.c:4689 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4689 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae

Scores

CVSS v3 5.5
EPSS 0.0025
EPSS Percentile 16.8%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

Status published
Products (12)
Linux/Linux < 5.0
Linux/Linux 5.0
Linux/Linux 5.10.70 - 5.10.*
Linux/Linux 5.14.9 - 5.14.*
Linux/Linux 5.15
Linux/Linux 5.4.150 - 5.4.*
Linux/Linux c454a46b5efd8eff8880e88ece2976e60a26bf35 - 0e6491b559704da720f6da09dd0a52c4df44c514
Linux/Linux c454a46b5efd8eff8880e88ece2976e60a26bf35 - 6345a0bee80139ea00a341c4202ebfd1534b5eb0
Linux/Linux c454a46b5efd8eff8880e88ece2976e60a26bf35 - 93937596e0652d50973f9dc944fea1694ac8cdfd
Linux/Linux c454a46b5efd8eff8880e88ece2976e60a26bf35 - b5fe7cdfee5901ce5513c30e554d51536e003bde
... and 2 more
Published May 21, 2024
Tracked Since Feb 18, 2026