selftests/bpf: Test widen_imprecise_scalars() with different stack depth
A test case for a situation when widen_imprecise_scalars() is called
with old->allocated_stack > cur->allocated_stack. Test structure:
def widening_stack_size_bug():
r1 = 0
for r6 in 0..1:
iterator_with_diff_stack_depth(r1)
r1 = 42
def iterator_with_diff_stack_depth(r1):
if r1 != 42:
use 128 bytes of stack
iterator based loop
iterator_with_diff_stack_depth() is verified with r1 == 0 first and
r1 == 42 next. Causing stack usage of 128 bytes on a first visit and 8
bytes on a second. Such arrangement triggered a KASAN error in
widen_imprecise_scalars().
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251114025730.772723-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
1 file changed
