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From: Chen Gang <gang.chen.5i5j@gmail.com>
To: agraf@suse.de, pbonzini@redhat.com
Cc: qemu-trivial@nongnu.org, qemu-ppc@nongnu.org,
	qemu-devel <qemu-devel@nongnu.org>,
	kvm@vger.kernel.org
Subject: [Qemu-devel] [PATCH] target-ppc: kvm: Fix memory overflow issue about strncat()
Date: Mon, 13 Oct 2014 22:36:02 +0800	[thread overview]
Message-ID: <543BE352.3080609@gmail.com> (raw)

strncat() will append additional '\0' to destination buffer, so need
additional 1 byte for it, or may cause memory overflow, just like other
area within QEMU have done.

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
---
 target-ppc/kvm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index 9c23c6b..66e7ce5 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -1794,8 +1794,8 @@ static uint64_t kvmppc_read_int_cpu_dt(const char *propname)
         return -1;
     }
 
-    strncat(buf, "/", sizeof(buf) - strlen(buf));
-    strncat(buf, propname, sizeof(buf) - strlen(buf));
+    strncat(buf, "/", sizeof(buf) - strlen(buf) - 1);
+    strncat(buf, propname, sizeof(buf) - strlen(buf) - 1);
 
     f = fopen(buf, "rb");
     if (!f) {
-- 
1.9.3

             reply	other threads:[~2014-10-13 14:30 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-13 14:36 Chen Gang [this message]
2014-10-13 14:47 ` [Qemu-devel] [PATCH] target-ppc: kvm: Fix memory overflow issue about strncat() Alexander Graf
2014-10-13 15:43   ` Chen Gang
2014-10-24  7:49   ` [Qemu-devel] [Qemu-trivial] " Michael Tokarev
2014-10-24  8:05     ` Alexander Graf
2014-10-24  8:19     ` Chen Gang

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