4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit cb12d72b27a6f41325ae23a11033cf5fedfa1b97 ]
Shifting the 1 by exp by an int can lead to sign-extension overlow when exp is 31 since 1 is an signed int and sign-extending this result to an unsigned long long will set the upper 32 bits. Fix this by shifting an unsigned long.
Detected by cppcheck: (warning) Shifting signed 32-bit value by 31 bits is undefined behaviour
Signed-off-by: Colin Ian King colin.king@canonical.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/atm/he.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/atm/he.c b/drivers/atm/he.c index 29f102dcfec49..329ce9072ee9f 100644 --- a/drivers/atm/he.c +++ b/drivers/atm/he.c @@ -717,7 +717,7 @@ static int he_init_cs_block_rcm(struct he_dev *he_dev) instead of '/ 512', use '>> 9' to prevent a call to divdu3 on x86 platforms */ - rate_cps = (unsigned long long) (1 << exp) * (man + 512) >> 9; + rate_cps = (unsigned long long) (1UL << exp) * (man + 512) >> 9;
if (rate_cps < 10) rate_cps = 10; /* 2.2.1 minimum payload rate is 10 cps */