Commit bab991cf authored Jun 13, 2020 by Gaurav Singh Committed by Richard Weinberger Oct 11, 2020

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>

parent ba4f184e

arch/um/drivers/vector_user.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -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) {
		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);

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