netdevsim: Avoid allocation warnings triggered from user space

We need to suppress warnings from sily map sizes. Also switch
from GFP_USER to GFP_KERNEL_ACCOUNT, I'm pretty sure I misunderstood
the flags when writing this code.

Fixes: 395cacb5f1a0 ("netdevsim: bpf: support fake map offload")
Reported-by: syzbot+ad24705d3fd6463b18c6@syzkaller.appspotmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220726213605.154204-1-kuba@kernel.org

diff --git a/drivers/net/netdevsim/bpf.c b/drivers/net/netdevsim/bpf.c
index a438202..5085426 100644 (file)
--- a/drivers/net/netdevsim/bpf.c
+++ b/drivers/net/netdevsim/bpf.c
@@ -351,10 +351,12 @@ nsim_map_alloc_elem(struct bpf_offloaded_map *offmap, unsigned int idx)
 {
        struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
 
-       nmap->entry[idx].key = kmalloc(offmap->map.key_size, GFP_USER);
+       nmap->entry[idx].key = kmalloc(offmap->map.key_size,
+                                      GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
        if (!nmap->entry[idx].key)
                return -ENOMEM;
-       nmap->entry[idx].value = kmalloc(offmap->map.value_size, GFP_USER);
+       nmap->entry[idx].value = kmalloc(offmap->map.value_size,
+                                        GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
        if (!nmap->entry[idx].value) {
                kfree(nmap->entry[idx].key);
                nmap->entry[idx].key = NULL;
@@ -496,7 +498,7 @@ nsim_bpf_map_alloc(struct netdevsim *ns, struct bpf_offloaded_map *offmap)
        if (offmap->map.map_flags)
                return -EINVAL;
 
-       nmap = kzalloc(sizeof(*nmap), GFP_USER);
+       nmap = kzalloc(sizeof(*nmap), GFP_KERNEL_ACCOUNT);
        if (!nmap)
                return -ENOMEM;