llc: Improve setsockopt() handling of malformed user input

[ Upstream commit 1465036b10 ]

copy_from_sockptr() is used incorrectly: return value is the number of
bytes that could not be copied. Since it's deprecated, switch to
copy_safe_from_sockptr().

Note: Keeping the `optlen != sizeof(int)` check as copy_safe_from_sockptr()
by itself would also accept optlen > sizeof(int). Which would allow a more
lenient handling of inputs.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Suggested-by: David Wei <dw@davidwei.uk>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Michal Luczaj 2024-11-19 14:31:41 +01:00 committed by Greg Kroah-Hartman
parent f688979e42
commit 981d647c6f

View File

@ -1099,7 +1099,7 @@ static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
lock_sock(sk);
if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
goto out;
rc = copy_from_sockptr(&opt, optval, sizeof(opt));
rc = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen);
if (rc)
goto out;
rc = -EINVAL;