media: v4l2-dv-timings: prevent possible overflow in v4l2_detect_gtf()
commit 3edd1fc48d2c045e8259561797c89fe78f01717e upstream.
In v4l2_detect_gtf(), it seems safer to cast the 32-bit image_width
variable to the 64-bit type u64 before multiplying to avoid
a possible overflow. The resulting object code even seems to
look better, at least on x86_64.
Found by Linux Verification Center (linuxtesting.org) with Svace.
[Sergey: rewrote the patch subject/descripition]
Fixes: c9bc9f5075 ("[media] v4l2-dv-timings: fix overflow in gtf timings calculation")
Cc: stable@vger.kernel.org
Signed-off-by: Karina Yankevich <k.yankevich@omp.ru>
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
committed by
Greg Kroah-Hartman
parent
b933486f6b
commit
baea1762cd
@@ -764,7 +764,7 @@ bool v4l2_detect_gtf(unsigned int frame_height,
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u64 num;
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u32 den;
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num = ((image_width * GTF_D_C_PRIME * (u64)hfreq) -
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num = (((u64)image_width * GTF_D_C_PRIME * hfreq) -
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((u64)image_width * GTF_D_M_PRIME * 1000));
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den = (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) *
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(2 * GTF_CELL_GRAN);
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@@ -774,7 +774,7 @@ bool v4l2_detect_gtf(unsigned int frame_height,
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u64 num;
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u32 den;
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num = ((image_width * GTF_S_C_PRIME * (u64)hfreq) -
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num = (((u64)image_width * GTF_S_C_PRIME * hfreq) -
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((u64)image_width * GTF_S_M_PRIME * 1000));
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den = (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) *
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(2 * GTF_CELL_GRAN);
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