55 lines
1.5 KiB
Diff
55 lines
1.5 KiB
Diff
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From 87f5d0c70bdb46d467d32e3c3a8d7a472c97e148 Mon Sep 17 00:00:00 2001
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From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>
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Date: Fri, 4 Jun 2021 15:58:25 +0400
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Subject: [PATCH 1/7] Add mtod_check()
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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Recent security issues demonstrate the lack of safety care when casting
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a mbuf to a particular structure type. At least, it should check that
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the buffer is large enough. The following patches will make use of this
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function.
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Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
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(cherry picked from commit 93e645e72a056ec0b2c16e0299fc5c6b94e4ca17)
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---
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src/mbuf.c | 11 +++++++++++
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src/mbuf.h | 1 +
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2 files changed, 12 insertions(+)
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diff --git a/src/mbuf.c b/src/mbuf.c
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index 54ec721..cb2e971 100644
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--- a/src/mbuf.c
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+++ b/src/mbuf.c
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@@ -222,3 +222,14 @@ struct mbuf *dtom(Slirp *slirp, void *dat)
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return (struct mbuf *)0;
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}
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+
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+void *mtod_check(struct mbuf *m, size_t len)
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+{
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+ if (m->m_len >= len) {
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+ return m->m_data;
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+ }
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+
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+ DEBUG_ERROR("mtod failed");
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+
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+ return NULL;
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+}
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diff --git a/src/mbuf.h b/src/mbuf.h
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index 546e785..2015e32 100644
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--- a/src/mbuf.h
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+++ b/src/mbuf.h
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@@ -118,6 +118,7 @@ void m_inc(struct mbuf *, int);
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void m_adj(struct mbuf *, int);
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int m_copy(struct mbuf *, struct mbuf *, int, int);
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struct mbuf *dtom(Slirp *, void *);
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+void *mtod_check(struct mbuf *, size_t len);
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static inline void ifs_init(struct mbuf *ifm)
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{
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--
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2.29.0
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