CVE-2024-34777

In the Linux kernel, the following vulnerability has been resolved:

dma-mapping: benchmark: fix node id validation

While validating node ids in map_benchmark_ioctl(), node_possible() may be provided with invalid argument outside of [0,MAX_NUMNODES-1] range leading to:

BUG: KASAN: wild-memory-access in map_benchmark_ioctl (kernel/dma/map_benchmark.c:214) Read of size 8 at addr 1fffffff8ccb6398 by task dma_map_benchma/971 CPU: 7 PID: 971 Comm: dma_map_benchma Not tainted 6.9.0-rc6 #37 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) Call Trace: dump_stack_lvl (lib/dump_stack.c:117) kasan_report (mm/kasan/report.c:603) kasan_check_range (mm/kasan/generic.c:189) variable_test_bit (arch/x86/include/asm/bitops.h:227) [inline] arch_test_bit (arch/x86/include/asm/bitops.h:239) [inline] _test_bit at (include/asm-generic/bitops/instrumented-non-atomic.h:142) [inline] node_state (include/linux/nodemask.h:423) [inline] map_benchmark_ioctl (kernel/dma/map_benchmark.c:214) full_proxy_unlocked_ioctl (fs/debugfs/file.c:333) __x64_sys_ioctl (fs/ioctl.c:890) do_syscall_64 (arch/x86/entry/common.c:83) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

Compare node ids with sane bounds first. NUMA_NO_NODE is considered a special valid case meaning that benchmarking kthreads wont be bound to a cpuset of a given node.

Found by Linux Verification Center (linuxtesting.org).

Weakness

The product reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Potential Mitigations

• Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
• When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
• Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
• To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/540.html

References

• https://git.kernel.org/stable/c/1ff05e723f7ca30644b8ec3fb093f16312e408ad
• https://git.kernel.org/stable/c/34a816d8735f3924b74be8e5bf766ade1f3bd10b
• https://git.kernel.org/stable/c/35d31c8bd4722b107f5a2f5ddddce839de04b936
• https://git.kernel.org/stable/c/63e7e05a48a35308aeddd7ecccb68363a5988e87
• https://git.kernel.org/stable/c/c57874265a3c5206d7aece3793bb2fc9abcd7570
• https://git.kernel.org/stable/c/1ff05e723f7ca30644b8ec3fb093f16312e408ad
• https://git.kernel.org/stable/c/34a816d8735f3924b74be8e5bf766ade1f3bd10b
• https://git.kernel.org/stable/c/35d31c8bd4722b107f5a2f5ddddce839de04b936
• https://git.kernel.org/stable/c/63e7e05a48a35308aeddd7ecccb68363a5988e87
• https://git.kernel.org/stable/c/c57874265a3c5206d7aece3793bb2fc9abcd7570