The patch titled
Subject: linux/bitmap.h: fix potential sign-extension overflow
has been added to the -mm tree. Its filename is
bitops-introduce-the-for_each_set_clump8-macro-fix.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/bitops-introduce-the-for_each_set_clump8-macro-fix.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/bitops-introduce-the-for_each_set_clump8-macro-fix.patch
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------------------------------------------------------
From: "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>
Subject: linux/bitmap.h: fix potential sign-extension overflow
In expression 0xff << offset, left shifting by more than 31 bits has
undefined behavior. Notice that the shift amount, *offset*, can be as
much as 63.
Fix this by adding suffix ULL to integer 0xFF.
Addresses Coverity 1487071 ("Bad bit shift operation")
Link: http://lkml.kernel.org/r/20191015184657.GA26541@embeddedor
Fixes: d33f5cbaadd8 ("bitops: introduce the for_each_set_clump8 macro")
Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
Cc: William Breathitt Gray <vilhelm.gray@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/bitmap.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/linux/bitmap.h~bitops-introduce-the-for_each_set_clump8-macro-fix
+++ a/include/linux/bitmap.h
@@ -520,7 +520,7 @@ static inline void bitmap_set_value8(uns
const size_t index = BIT_WORD(start);
const unsigned long offset = start % BITS_PER_LONG;
- map[index] &= ~(0xFF << offset);
+ map[index] &= ~(0xFFULL << offset);
map[index] |= value << offset;
}
_
Patches currently in -mm which might be from gustavo@xxxxxxxxxxxxxx are
bitops-introduce-the-for_each_set_clump8-macro-fix.patch
