As part of the work to perform bounds checking on all memcpy() uses, replace the open-coded a deserialization of bytes out of memory into a trailing flexible array by using a flex_array.h helper to perform the allocation, bounds checking, and copying. Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: Eric Dumazet <edumazet@xxxxxxxxxx> Cc: Jakub Kicinski <kuba@xxxxxxxxxx> Cc: Paolo Abeni <pabeni@xxxxxxxxxx> Cc: Hulk Robot <hulkci@xxxxxxxxxx> Cc: Yang Yingliang <yangyingliang@xxxxxxxxxx> Cc: netdev@xxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- include/net/garp.h | 4 ++-- net/802/garp.c | 9 +++------ 2 files changed, 5 insertions(+), 8 deletions(-) diff --git a/include/net/garp.h b/include/net/garp.h index 4d9a0c6a2e5f..ec087ae534e7 100644 --- a/include/net/garp.h +++ b/include/net/garp.h @@ -80,8 +80,8 @@ struct garp_attr { struct rb_node node; enum garp_applicant_state state; u8 type; - u8 dlen; - unsigned char data[]; + DECLARE_FLEX_ARRAY_ELEMENTS_COUNT(u8, dlen); + DECLARE_FLEX_ARRAY_ELEMENTS(unsigned char, data); }; enum garp_applications { diff --git a/net/802/garp.c b/net/802/garp.c index f6012f8e59f0..72743ed00a54 100644 --- a/net/802/garp.c +++ b/net/802/garp.c @@ -168,7 +168,7 @@ static struct garp_attr *garp_attr_create(struct garp_applicant *app, const void *data, u8 len, u8 type) { struct rb_node *parent = NULL, **p = &app->gid.rb_node; - struct garp_attr *attr; + struct garp_attr *attr = NULL; int d; while (*p) { @@ -184,13 +184,10 @@ static struct garp_attr *garp_attr_create(struct garp_applicant *app, return attr; } } - attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC); - if (!attr) - return attr; + if (mem_to_flex_dup(&attr, data, len, GFP_ATOMIC)) + return NULL; attr->state = GARP_APPLICANT_VO; attr->type = type; - attr->dlen = len; - memcpy(attr->data, data, len); rb_link_node(&attr->node, parent, p); rb_insert_color(&attr->node, &app->gid); -- 2.32.0