On 04/23/2013 08:42 AM, Chen Gang wrote:
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.
Per parameter length in ibm,get-system-parameter RTAS call is limited to 1026
bytes (1024 bytes of data + 2 bytes length). And 'rtas_data_buf' was set to 0
(first 1026 bytes) before call RTAS call. At the worst if we get junk in RTAS
output length field helps to exit from the while loop. So I don't think we need
this patch.
-Vasant
Signed-off-by: Chen Gang<gang.c...@asianux.com>
---
arch/powerpc/kernel/lparcfg.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/kernel/lparcfg.c b/arch/powerpc/kernel/lparcfg.c
index 801a757..d92f387 100644
--- a/arch/powerpc/kernel/lparcfg.c
+++ b/arch/powerpc/kernel/lparcfg.c
@@ -299,6 +299,7 @@ static void parse_system_parameter_string(struct seq_file
*m)
__pa(rtas_data_buf),
RTAS_DATA_BUF_SIZE);
memcpy(local_buffer, rtas_data_buf, SPLPAR_MAXLENGTH);
+ local_buffer[SPLPAR_MAXLENGTH - 1] = '\0';
spin_unlock(&rtas_data_buf_lock);
if (call_status != 0) {
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