[PATCH 3.5 31/64] powerpc/pseries/lparcfg: Fix possible overflow are more than 1026

From: Luis Henriques
Date: Mon Oct 28 2013 - 10:57:10 EST -stable review patch. If anyone has any objections, please let me know.


From: Chen Gang <gang.chen@xxxxxxxxxxx>

commit 5676005acf26ab7e924a8438ea4746e47d405762 upstream.

need set '\0' for 'local_buffer'.

SPLPAR_MAXLENGTH is 1026, RTAS_DATA_BUF_SIZE is 4096. so the contents of
rtas_data_buf may truncated in memcpy.

if contents are really truncated.
the splpar_strlen is more than 1026. the next while loop checking will
not find the end of buffer. that will cause memory access violation.

Signed-off-by: Chen Gang <gang.chen@xxxxxxxxxxx>
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
arch/powerpc/kernel/lparcfg.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/kernel/lparcfg.c b/arch/powerpc/kernel/lparcfg.c
index 7ebbae0..f62fda1 100644
--- a/arch/powerpc/kernel/lparcfg.c
+++ b/arch/powerpc/kernel/lparcfg.c
@@ -307,6 +307,7 @@ static void parse_system_parameter_string(struct seq_file *m)
memcpy(local_buffer, rtas_data_buf, SPLPAR_MAXLENGTH);
+ local_buffer[SPLPAR_MAXLENGTH - 1] = '\0';

if (call_status != 0) {

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