From: Neelesh Gupta Date: Thu, 16 Jul 2015 11:16:54 +0000 (+0530) Subject: ipmi/powernv: Fix potential invalid pointer dereference X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=cca85f19c260df495a487495479c67803b25fa8a;p=linux-beck.git 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 --- 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; }