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| author | Yonghong Song <yhs@fb.com> | 2021-02-11 16:59:26 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-03-04 11:37:33 +0100 |
| commit | 94c0e3551594011e6ffceca2c87196480010ef0b (patch) | |
| tree | 73d203747c2bbd17e831273c1067796312f1e287 | |
| parent | c8de71a7ae39e5f55b4ef5851387e2661c87f30b (diff) | |
| download | linux-rt-94c0e3551594011e6ffceca2c87196480010ef0b.tar.gz | |
bpf: Fix an unitialized value in bpf_iter
[ Upstream commit 17d8beda277a36203585943e70c7909b60775fd5 ]
Commit 15d83c4d7cef ("bpf: Allow loading of a bpf_iter program")
cached btf_id in struct bpf_iter_target_info so later on
if it can be checked cheaply compared to checking registered names.
syzbot found a bug that uninitialized value may occur to
bpf_iter_target_info->btf_id. This is because we allocated
bpf_iter_target_info structure with kmalloc and never initialized
field btf_id afterwards. This uninitialized btf_id is typically
compared to a u32 bpf program func proto btf_id, and the chance
of being equal is extremely slim.
This patch fixed the issue by using kzalloc which will also
prevent future likely instances due to adding new fields.
Fixes: 15d83c4d7cef ("bpf: Allow loading of a bpf_iter program")
Reported-by: syzbot+580f4f2a272e452d55cb@syzkaller.appspotmail.com
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210212005926.2875002-1-yhs@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | kernel/bpf/bpf_iter.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c index 8f10e30ea0b0..e8957e911de3 100644 --- a/kernel/bpf/bpf_iter.c +++ b/kernel/bpf/bpf_iter.c @@ -273,7 +273,7 @@ int bpf_iter_reg_target(const struct bpf_iter_reg *reg_info) { struct bpf_iter_target_info *tinfo; - tinfo = kmalloc(sizeof(*tinfo), GFP_KERNEL); + tinfo = kzalloc(sizeof(*tinfo), GFP_KERNEL); if (!tinfo) return -ENOMEM; |