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authorStanislav Fomichev <sdf@google.com>2019-01-16 14:03:16 -0800
committerDaniel Borkmann <daniel@iogearbox.net>2019-01-17 16:42:35 +0100
commit4af396ae4836c4ecab61e975b8e61270c551894d (patch)
tree3ea744486f9d9c3582f038e5a04d0aac47812e3d
parent0b698005a9d11c0e91141ec11a2c4918a129f703 (diff)
download96b-common-4af396ae4836c4ecab61e975b8e61270c551894d.tar.gz
bpf: zero out build_id for BPF_STACK_BUILD_ID_IP
When returning BPF_STACK_BUILD_ID_IP from stack_map_get_build_id_offset, make sure that build_id field is empty. Since we are using percpu free list, there is a possibility that we might reuse some previous bpf_stack_build_id with non-zero build_id. Fixes: 615755a77b24 ("bpf: extend stackmap to save binary_build_id+offset instead of address") Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
-rw-r--r--kernel/bpf/stackmap.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index f9df545e92f6..d43b14535827 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -314,6 +314,7 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs,
for (i = 0; i < trace_nr; i++) {
id_offs[i].status = BPF_STACK_BUILD_ID_IP;
id_offs[i].ip = ips[i];
+ memset(id_offs[i].build_id, 0, BPF_BUILD_ID_SIZE);
}
return;
}
@@ -324,6 +325,7 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs,
/* per entry fall back to ips */
id_offs[i].status = BPF_STACK_BUILD_ID_IP;
id_offs[i].ip = ips[i];
+ memset(id_offs[i].build_id, 0, BPF_BUILD_ID_SIZE);
continue;
}
id_offs[i].offset = (vma->vm_pgoff << PAGE_SHIFT) + ips[i]