In the Linux kernel, the following vulnerability has been resolved:
phonet: pep: do not write beyond optlen in getsockopt
pep_getsockopt() clamps the reported length to the caller's buffer with
min_t(), but then stores the value with put_user(val, (int __user *)
optval), which always writes sizeof(int) bytes. A getsockopt() call with
an optlen smaller than sizeof(int) thus reports the clamped length yet
writes a full int, one to three bytes past the user buffer.
Write the value with copy_to_user() bounded by len, so at most optlen
bytes are copied, matching the length reported back to userspace.
References 8
https://git.kernel.org/stable/c/056eea1a2068ad2fb7c3093c5f1095268f87d0c7
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/1bf499e438da80455e258049bce60ffb3a53f3fa
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/6054fed6bad08b6d03973e8ffca7f0c9394d1c30
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/77e5eb0e192aec6710c03ca8144582fd2af36ca4
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/95e0ed2439dd1792eb454c68ae8d10f30ffe3bff
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/c4487e4d5309de587479ecc2f5173b49586f46f4
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/eac733a0b6fe0a52d91f9f623425735ed50ac6c2
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/f97022fefe6eb06ee18549d603420440f2959802
416baaa9-dc9f-4396-8d5f-8c081fb06d67