5.4-stable review patch. If anyone has any objections, please let me know.
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From: Karina Yankevich k.yankevich@omp.ru
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: c9bc9f50753d ("[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 --- drivers/media/v4l2-core/v4l2-dv-timings.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/media/v4l2-core/v4l2-dv-timings.c +++ b/drivers/media/v4l2-core/v4l2-dv-timings.c @@ -755,7 +755,7 @@ bool v4l2_detect_gtf(unsigned frame_heig u64 num; u32 den;
- num = ((image_width * GTF_D_C_PRIME * (u64)hfreq) - + num = (((u64)image_width * GTF_D_C_PRIME * hfreq) - ((u64)image_width * GTF_D_M_PRIME * 1000)); den = (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) * (2 * GTF_CELL_GRAN); @@ -765,7 +765,7 @@ bool v4l2_detect_gtf(unsigned frame_heig u64 num; u32 den;
- num = ((image_width * GTF_S_C_PRIME * (u64)hfreq) - + num = (((u64)image_width * GTF_S_C_PRIME * hfreq) - ((u64)image_width * GTF_S_M_PRIME * 1000)); den = (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) * (2 * GTF_CELL_GRAN);