From: Liu ShuoX <shuox.liu@intel.com>
Date: Mon, 17 Mar 2014 20:57:49 +0000 (-0700)
Subject: pstore: Fix NULL pointer fault if get NULL prz in ramoops_get_next_prz
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b0aa931fb84431394d995472d0af2a6c2b61064d;p=linux-beck.git

pstore: Fix NULL pointer fault if get NULL prz in ramoops_get_next_prz

ramoops_get_next_prz get the prz according the paramters. If it get a
uninitialized prz, access its members by following persistent_ram_old_size(prz)
will cause a NULL pointer crash.
Ex: if ftrace_size is 0, fprz will be NULL.

Fix it by return NULL in advance.

Signed-off-by: Liu ShuoX <shuox.liu@intel.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 1daed280f1b6..6f96d8c2a711 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -119,6 +119,8 @@ ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
 		return NULL;
 
 	prz = przs[i];
+	if (!prz)
+		return NULL;
 
 	/* Update old/shadowed buffer. */
 	if (update)