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| author | Stanislav Fomichev <sdf@google.com> | 2019-01-16 23:03:16 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2019-01-17 16:42:35 +0100 |
| commit | 4af396ae4836c4ecab61e975b8e61270c551894d (patch) | |
| tree | 3ea744486f9d9c3582f038e5a04d0aac47812e3d /kernel/bpf/stackmap.c | |
| parent | bpf: don't assume build-id length is always 20 bytes (diff) | |
| download | linux-4af396ae4836c4ecab61e975b8e61270c551894d.tar.xz linux-4af396ae4836c4ecab61e975b8e61270c551894d.zip | |
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>
Diffstat (limited to 'kernel/bpf/stackmap.c')
| -rw-r--r-- | kernel/bpf/stackmap.c | 2 |
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] |