sym_get_near_range_bound() is meant to check whether the given value is
outside of the active range of an int/hex symbol, and is called with the
symbol's current value from sym_calc_value() and with the default value
from sym_get_string_default().
Since commit 9b8719973e ("kconfig: use unsigned integers for hex range
checks") it ignores its value argument and uses the current value of the
symbol (via sym_get_range_val()) instead. As a result, an out-of-range
default is no longer clamped in sym_get_string_default(), and
savedefconfig writes out values that are equal to the effective default
again, for example CONFIG_A=4 for:
config A
int "a"
range 1 4
default 8
The existing savedefconfig_range test did not catch this because it only
covers symbols without a prompt.
Parse the value argument again, and add a test case for a symbol with a
prompt.
Found while fuzzing Kconfig input with ASan/UBSan.
Fixes: 9b8719973e ("kconfig: use unsigned integers for hex range checks")
Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Leizhen Zhang <lzsx618@gmail.com>
Tested-by: Julian Braha <julianbraha@gmail.com>
Reviewed-by: Julian Braha <julianbraha@gmail.com>
Link: https://patch.msgid.link/20261008164540.3686383-1-lzsx618@gmail.com
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
a8f72a75b3