um: Fix null pointer dereference in vector_user_bpf
The bpf_prog is being checked for !NULL after uml_kmalloc
but later its used directly for example:
bpf_prog->filter = bpf and is also later returned upon
success. Fix this, do a NULL check and return right away.
Signed-off-by: Gaurav Singh <gaurav1086@gmail.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index c4a0f26..0e6d671 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -789,10 +789,12 @@ void *uml_vector_user_bpf(char *filename)
return false;
}
bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL);
- if (bpf_prog != NULL) {
- bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter);
- bpf_prog->filter = NULL;
+ if (bpf_prog == NULL) {
+ printk(KERN_ERR "Failed to allocate bpf prog buffer");
+ return NULL;
}
+ bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter);
+ bpf_prog->filter = NULL;
ffd = os_open_file(filename, of_read(OPENFLAGS()), 0);
if (ffd < 0) {
printk(KERN_ERR "Error %d opening bpf file", -errno);