From cca85f19c260df495a487495479c67803b25fa8a Mon Sep 17 00:00:00 2001 From: Neelesh Gupta Date: Thu, 16 Jul 2015 16:46:54 +0530 Subject: [PATCH] ipmi/powernv: Fix potential invalid pointer dereference If the OPAL call to receive the ipmi message fails, then we free up the smi message and return. But, the driver still holds the reference to old smi message in the 'cur_msg' which can potentially be accessed later and freed again leading to kernel oops. To fix it up, The kernel driver should reset the 'cur_msg' and send reply to the user in addition to freeing the message. Signed-off-by: Neelesh Gupta Fixed a checkpatch warning dealing with an else after a return. Signed-off-by: Corey Minyard --- drivers/char/ipmi/ipmi_powernv.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/char/ipmi/ipmi_powernv.c b/drivers/char/ipmi/ipmi_powernv.c index 9b409c0f14f7..62c0c634280f 100644 --- a/drivers/char/ipmi/ipmi_powernv.c +++ b/drivers/char/ipmi/ipmi_powernv.c @@ -143,8 +143,15 @@ static int ipmi_powernv_recv(struct ipmi_smi_powernv *smi) pr_devel("%s: -> %d (size %lld)\n", __func__, rc, rc == 0 ? size : 0); if (rc) { + /* If came via the poll, and response was not yet ready */ + if (rc == OPAL_EMPTY) { + spin_unlock_irqrestore(&smi->msg_lock, flags); + return 0; + } + + smi->cur_msg = NULL; spin_unlock_irqrestore(&smi->msg_lock, flags); - ipmi_free_smi_msg(msg); + send_error_reply(smi, msg, IPMI_ERR_UNSPECIFIED); return 0; } -- 2.20.1