bpf: Mark bpf prog stack with kmsan_unposion_memory in interpreter mode

syzbot reported uninit memory usages during map_{lookup,delete}_elem.
It is due to the "void *key" passed to the helper. bpf allows uninit
stack memory access for bpf prog with the right privileges. This patch
uses kmsan_unpoison_memory() to mark the stack as initialized.

Reported-by: syzbot+603bcd9b0bf1d94dbb9b@syzkaller.appspotmail.com
Reported-by: syzbot+eb02dc7f03dce0ef39f3@syzkaller.appspotmail.com
Reported-by: syzbot+1a3cf6f08d68868f9db3@syzkaller.appspotmail.com
Reported-by: syzbot+b4e65ca24fd4d0c734c3@syzkaller.appspotmail.com
Reported-by: syzbot+d2b113dc9fea5e1d2848@syzkaller.appspotmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
1 file changed