From 92010ab6dbacc0e0f3566d92a84ff00a939e7fd4 Mon Sep 17 00:00:00 2001 From: Lee Yongjun Date: Tue, 20 Jan 2026 22:18:27 +0900 Subject: [PATCH] lib/find_bit: fix uninitialized variable use in FIND_NTH_BIT In the FIND_NTH_BIT macro, if the 'size' parameter is 0, both the loop conditions and the modulo condition are not met. Consequently, the 'tmp' variable remains uninitialized before being used in the 'found' label. This results in the following smatch errors: lib/find_bit.c:164 __find_nth_bit() error: uninitialized symbol 'tmp'. lib/find_bit.c:171 __find_nth_and_bit() error: uninitialized symbol 'tmp'. lib/find_bit.c:178 __find_nth_andnot_bit() error: uninitialized symbol 'tmp'. lib/find_bit.c:187 __find_nth_and_andnot_bit() error: uninitialized symbol 'tmp'. Initialize 'tmp' to 0 to ensure that fns() operates on a zeroed value (no bits set) when size is 0, preventing the use of garbage values. [Yury: size == 0 is generally a sign of error on client side, and in this case, any returned value is OK because the returned value would be greater than 'size'. Applying the patch to reduce the checker noise.] Signed-off-by: Lee Yongjun Signed-off-by: Yury Norov --- lib/find_bit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/find_bit.c b/lib/find_bit.c index d4b5a29e3e728..5a0066c26d9a6 100644 --- a/lib/find_bit.c +++ b/lib/find_bit.c @@ -71,7 +71,7 @@ out: \ #define FIND_NTH_BIT(FETCH, size, num) \ ({ \ - unsigned long sz = (size), nr = (num), idx, w, tmp; \ + unsigned long sz = (size), nr = (num), idx, w, tmp = 0; \ \ for (idx = 0; (idx + 1) * BITS_PER_LONG <= sz; idx++) { \ if (idx * BITS_PER_LONG + nr >= sz) \ -- 2.47.3