Commit 3d042592ebd4 for kernel
commit 3d042592ebd4c7e44974d556de0b727cb7db4dab
Author: Chenguang Zhao <zhaochenguang@kylinos.cn>
Date: Mon May 11 09:43:43 2026 +0800
ethtool: fix ethnl_bitmap32_not_zero() bit interval semantics
ethnl_bitmap32_not_zero() should return true if some bit in [start, end)
is set:
- Fix inverted memchr_inv() sense: return true when the scan finds a
non-zero byte, not when the middle words are all zero.
- Return false for an empty interval (end <= start).
- When end is 32-bit aligned, indices in [start, end) do not include any
bits from map[end_word]; return false after earlier checks found no
non-zero data.
Fixes: 10b518d4e6dd ("ethtool: netlink bitset handling")
Signed-off-by: Chenguang Zhao <zhaochenguang@kylinos.cn>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
diff --git a/net/ethtool/bitset.c b/net/ethtool/bitset.c
index 8bb98d3ea3db..a3a2cc6480a0 100644
--- a/net/ethtool/bitset.c
+++ b/net/ethtool/bitset.c
@@ -92,7 +92,7 @@ static bool ethnl_bitmap32_not_zero(const u32 *map, unsigned int start,
u32 mask;
if (end <= start)
- return true;
+ return false;
if (start % 32) {
mask = ethnl_upper_bits(start);
@@ -105,11 +105,11 @@ static bool ethnl_bitmap32_not_zero(const u32 *map, unsigned int start,
start_word++;
}
- if (!memchr_inv(map + start_word, '\0',
- (end_word - start_word) * sizeof(u32)))
+ if (memchr_inv(map + start_word, '\0',
+ (end_word - start_word) * sizeof(u32)))
return true;
if (end % 32 == 0)
- return true;
+ return false;
return map[end_word] & ethnl_lower_bits(end);
}