Messages in this thread |  | | Date | Wed, 22 Oct 2014 14:48:29 +0200 | From | Jan Kara <> | Subject | Re: [PATCH] bitmap: Fix undefined shift in __bitmap_shift_left() |
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On Wed 22-10-14 14:43:51, Jan Kara wrote: > It __bitmap_shift_left() is asked to shift by a multiple of > BITS_PER_LONG, it will try to shift a long value by BITS_PER_LONG bits > which is undefined. Change the function to take this into account. > > Coverity-id: 1192175 > CC: Rasmus Villemoes <linux@rasmusvillemoes.dk> > CC: stable@vger.kernel.org > Signed-off-by: Jan Kara <jack@suse.cz> Oops, there's one more occurence of this. I'll send an updated patch.
Honza > --- > lib/bitmap.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/lib/bitmap.c b/lib/bitmap.c > index cd250a2e14cb..02a8a439fcc7 100644 > --- a/lib/bitmap.c > +++ b/lib/bitmap.c > @@ -172,7 +172,9 @@ void __bitmap_shift_left(unsigned long *dst, > upper = src[k]; > if (left && k == lim - 1) > upper &= (1UL << left) - 1; > - dst[k + off] = lower >> (BITS_PER_LONG - rem) | upper << rem; > + dst[k + off] = upper << rem; > + if (rem) > + dst[k + off] |= lower >> (BITS_PER_LONG - rem); > if (left && k + off == lim - 1) > dst[k + off] &= (1UL << left) - 1; > } > -- > 1.8.1.4 > -- Jan Kara <jack@suse.cz> SUSE Labs, CR
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