From 530e214c5b5acbfaf819d884b196f3c61f5eca3d Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Mon, 28 Feb 2022 15:23:32 -0800 Subject: bpf, test_run: Fix overflow in XDP frags bpf_test_finish Syzkaller reports another issue: WARNING: CPU: 0 PID: 10775 at include/linux/thread_info.h:230 check_copy_size include/linux/thread_info.h:230 [inline] WARNING: CPU: 0 PID: 10775 at include/linux/thread_info.h:230 copy_to_user include/linux/uaccess.h:199 [inline] WARNING: CPU: 0 PID: 10775 at include/linux/thread_info.h:230 bpf_test_finish.isra.0+0x4b2/0x680 net/bpf/test_run.c:171 This can happen when the userspace buffer is smaller than head + frags. Return ENOSPC in this case. Fixes: 7855e0db150a ("bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature") Reported-by: syzbot+5f81df6205ecbbc56ab5@syzkaller.appspotmail.com Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann Cc: Lorenzo Bianconi Link: https://lore.kernel.org/bpf/20220228232332.458871-1-sdf@google.com --- net/bpf/test_run.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'net/bpf/test_run.c') diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index f08034500813..eb129e48f90b 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -150,6 +150,11 @@ static int bpf_test_finish(const union bpf_attr *kattr, if (data_out) { int len = sinfo ? copy_size - sinfo->xdp_frags_size : copy_size; + if (len < 0) { + err = -ENOSPC; + goto out; + } + if (copy_to_user(data_out, data, len)) goto out; -- cgit v1.2.3-59-g8ed1b