parse_system_parameter_string() copies the shared processor attribute sysparm 
into a fixed local work buffer one byte at a time, but it never checks whether 
the next byte still fits. A long token without an early comma or NUL can 
therefore run past SPLPAR_MAXLENGTH.

Stop parsing once the local token buffer is full instead of writing past the 
fixed destination.

Signed-off-by: Pengpeng Hou <[email protected]>
---
 arch/powerpc/platforms/pseries/lparcfg.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/lparcfg.c 
b/arch/powerpc/platforms/pseries/lparcfg.c
index 8821c378bfff..1bf2312f3e04 100644
--- a/arch/powerpc/platforms/pseries/lparcfg.c
+++ b/arch/powerpc/platforms/pseries/lparcfg.c
@@ -418,6 +418,10 @@ static void parse_system_parameter_string(struct seq_file 
*m)
                w_idx = 0;
                idx = 0;
                while ((*local_buffer) && (idx < splpar_strlen)) {
+                       if (w_idx >= SPLPAR_MAXLENGTH - 1) {
+                               pr_warn_once("lparcfg: shared processor 
attribute token is too long\n");
+                               break;
+                       }
                        workbuffer[w_idx++] = local_buffer[idx++];
                        if ((local_buffer[idx] == ',')
                            || (local_buffer[idx] == '\0')) {
-- 
2.50.1 (Apple Git-155)


Reply via email to