From ffe4cfc3da5e61555aca189e2432ee637fd12eec Mon Sep 17 00:00:00 2001 From: Jack Morgenstein Date: Tue, 22 Jan 2019 15:19:45 +0200 Subject: [PATCH] net/mlx4_core: Fix error handling when initializing CQ bufs in the driver Procedure mlx4_init_user_cqes() handles returns by copy_to_user incorrectly. copy_to_user() returns the number of bytes not copied. Thus, a non-zero return should be treated as a -EFAULT error (as is done elsewhere in the kernel). However, mlx4_init_user_cqes() error handling simply returns the number of bytes not copied (instead of -EFAULT). Note, though, that this is a harmless bug: procedure mlx4_alloc_cq() (which is the only caller of mlx4_init_user_cqes()) treats any non-zero return as an error, but that returned error value is processed internally, and not passed further up the call stack. In addition, fixes the following sparse warning: warning: incorrect type in argument 1 (different address spaces) expected void [noderef] *to got void *buf Fixes: e45678973dcb ("{net, IB}/mlx4: Initialize CQ buffers in the driver when possible") Reported by: Dan Carpenter Signed-off-by: Jack Morgenstein Signed-off-by: Tariq Toukan Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlx4/cq.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/cq.c b/drivers/net/ethernet/mellanox/mlx4/cq.c index db909b6069b5..65f8a4b6ed0c 100644 --- a/drivers/net/ethernet/mellanox/mlx4/cq.c +++ b/drivers/net/ethernet/mellanox/mlx4/cq.c @@ -306,14 +306,16 @@ static int mlx4_init_user_cqes(void *buf, int entries, int cqe_size) if (entries_per_copy < entries) { for (i = 0; i < entries / entries_per_copy; i++) { - err = copy_to_user(buf, init_ents, PAGE_SIZE); + err = copy_to_user((void __user *)buf, init_ents, PAGE_SIZE) ? + -EFAULT : 0; if (err) goto out; buf += PAGE_SIZE; } } else { - err = copy_to_user(buf, init_ents, entries * cqe_size); + err = copy_to_user((void __user *)buf, init_ents, entries * cqe_size) ? + -EFAULT : 0; } out: -- 2.11.0