CVE-2024-53151

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

svcrdma: Address an integer overflow

Dan Carpenter reports:

Commit 78147ca8b4a9 (svcrdma: Add a parsed chunk list data structure) from Jun 22, 2020 (linux-next), leads to the following Smatch static checker warning:

net/sunrpc/xprtrdma/svc_rdma_recvfrom.c:498 xdr_check_write_chunk() warn: potential user controlled sizeof overflow segcount * 4 * 4

net/sunrpc/xprtrdma/svc_rdma_recvfrom.c 488 static bool xdr_check_write_chunk(struct svc_rdma_recv_ctxt *rctxt) 489 { 490 u32 segcount; 491 __be32 *p; 492 493 if (xdr_stream_decode_u32(&rctxt->rc_stream, &segcount)) ^^^^^^^^

494                 return false;
495
496         /* A bogus segcount causes this buffer overflow check to fail. */
497         p = xdr_inline_decode(&rctxt->rc_stream,

–> 498 segcount * rpcrdma_segment_maxsz * sizeof(*p));

segcount is an untrusted u32. On 32bit systems anything >= SIZE_MAX / 16 will have an integer overflow and some those values will be accepted by xdr_inline_decode().

Weakness

The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control.

Affected Software

Potential Mitigations

• Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
• If possible, choose a language or compiler that performs automatic bounds checking.
• Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
• Use libraries or frameworks that make it easier to handle numbers without unexpected consequences.
• Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++). [REF-106]
• Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range.
• Use unsigned integers where possible. This makes it easier to perform validation for integer overflows. When signed integers are required, ensure that the range check includes minimum values as well as maximum values.
• Understand the programming language’s underlying representation and how it interacts with numeric calculation (CWE-681). Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, “not-a-number” calculations, and how the language handles numbers that are too large or too small for its underlying representation. [REF-7]
• Also be careful to account for 32-bit, 64-bit, and other potential differences that may affect the numeric representation.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/92.html

References

• https://git.kernel.org/stable/c/21e1cf688fb0397788c8dd42e1e0b08d58ac5c7b
• https://git.kernel.org/stable/c/3c63d8946e578663b868cb9912dac616ea68bfd0
• https://git.kernel.org/stable/c/4cbc3ba6dc2f746497cade60bcbaa82ae3696689
• https://git.kernel.org/stable/c/838dd342962cef4c320632a5af48d3c31f2f9877
• https://git.kernel.org/stable/c/c1f8195bf68edd2cef0f18a4cead394075a54b5a
• https://git.kernel.org/stable/c/e5c440c227ecdc721f2da0dd88b6358afd1031a7