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From: Dongliang Mu <mudongliangabcd@gmail.com>
To: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@kernel.org>, Willy Tarreau <w@1wt.eu>
Cc: Dongliang Mu <mudongliangabcd@gmail.com>,
	syzbot+f3e749d4c662818ae439@syzkaller.appspotmail.com,
	netdev@vger.kernel.org, bpf@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] bpf: fix kmalloc bug in bpf_check
Date: Mon, 13 Sep 2021 19:02:46 +0800	[thread overview]
Message-ID: <20210913110246.2955737-1-mudongliangabcd@gmail.com> (raw)

Since 7661809d493b ("mm: don't allow oversized kvmalloc() calls
") does not allow oversized kvmalloc, it triggers a kmalloc bug warning
at bpf_check.

Fix it by adding a sanity check in th check_btf_line.

Reported-by: syzbot+f3e749d4c662818ae439@syzkaller.appspotmail.com
Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls")
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
---
 kernel/bpf/verifier.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 047ac4b4703b..3c5a79f78bc5 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -9913,6 +9913,9 @@ static int check_btf_line(struct bpf_verifier_env *env,
 	if (!nr_linfo)
 		return 0;
 
+	if (nr_linfo > INT_MAX/sizeof(struct bpf_line_info))
+		return -EINVAL;
+
 	rec_size = attr->line_info_rec_size;
 	if (rec_size < MIN_BPF_LINEINFO_SIZE ||
 	    rec_size > MAX_LINEINFO_REC_SIZE ||
-- 
2.25.1


             reply	other threads:[~2021-09-13 11:03 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-13 11:02 Dongliang Mu [this message]
2021-09-13 15:33 ` [PATCH] bpf: fix kmalloc bug in bpf_check Yonghong Song
2021-09-13 15:36   ` Dongliang Mu

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