From: Barret Rhoden <brho@google.com>
Date: Fri, 7 Apr 2023 00:18:08 +0000 (-0400)
Subject: bpf: ensure all memory is initialized in bpf_get_current_comm
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f3f21349779776135349a8e6f114a1485b2476b7;p=linux.git

bpf: ensure all memory is initialized in bpf_get_current_comm

BPF helpers that take an ARG_PTR_TO_UNINIT_MEM must ensure that all of
the memory is set, including beyond the end of the string.

Signed-off-by: Barret Rhoden <brho@google.com>
Link: https://lore.kernel.org/r/20230407001808.1622968-1-brho@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 6be16db9f1882..b6a5cda5bb597 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -258,7 +258,7 @@ BPF_CALL_2(bpf_get_current_comm, char *, buf, u32, size)
 		goto err_clear;
 
 	/* Verifier guarantees that size > 0 */
-	strscpy(buf, task->comm, size);
+	strscpy_pad(buf, task->comm, size);
 	return 0;
 err_clear:
 	memset(buf, 0, size);