linux/dim: Fix overflow in dim calculation

While using net_dim, a dim_sample was used without ever initializing the
comps value. Added use of DIV_ROUND_DOWN_ULL() to prevent potential
overflow, it should not be a problem to save the final result in an int
because after the division by epms the value should not be larger than a
few thousand.

[ 1040.127124] UBSAN: Undefined behaviour in lib/dim/dim.c:78:23
[ 1040.130118] signed integer overflow:
[ 1040.131643] 134718714 * 100 cannot be represented in type 'int'

Fixes: 398c2b05bb ("linux/dim: Add completions count to dim_sample")
Signed-off-by: Yamin Friedman <yaminf@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Yamin Friedman
2019-07-23 10:22:47 +03:00
committed by David S. Miller
parent c8ec4632c6
commit f06d0ca458
5 changed files with 7 additions and 7 deletions

View File

@@ -1895,7 +1895,7 @@ static int bcmgenet_rx_poll(struct napi_struct *napi, int budget)
{
struct bcmgenet_rx_ring *ring = container_of(napi,
struct bcmgenet_rx_ring, napi);
struct dim_sample dim_sample;
struct dim_sample dim_sample = {};
unsigned int work_done;
work_done = bcmgenet_desc_rx(ring, budget);