snprintf() returns number of bytes that were copied if there is no overflow.
This code uses return value as number of copied bytes. Theoretically format
string '%lu.%09lu %pI4:%u %pI4:%u %d %#x %#x %u %u %u %u\n' may be expanded
up to 163 bytes. In reality tv.tv_sec is just few bytes instead of 20, 2 ports
are just 5 bytes each instead of 10, length is 5 bytes instead of 10. The rest
is an unstrusted input. Theoretically if tv_sec is big then copy_to_user() would
overflow tbuf.
tbuf was increased to fit in 163 bytes. snprintf() is used to follow return
value semantic.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Vasiliy Kulikov
dda0b38692