linux-kernel - [BUG]: mm/vmalloc: uninitialized variable access in pcpu_get_vm

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190617121427.77565-1-arnd@arndb.de>
Date:   Mon, 17 Jun 2019 14:14:11 +0200
From:   Arnd Bergmann <arnd@...db.de>
To:     unlisted-recipients:; (no To-header on input)
Cc:     Arnd Bergmann <arnd@...db.de>,
        "Uladzislau Rezki (Sony)" <urezki@...il.com>,
        Roman Gushchin <guro@...com>, Michal Hocko <mhocko@...e.com>,
        Matthew Wilcox <willy@...radead.org>,
        Thomas Garnier <thgarnie@...gle.com>,
        Oleksiy Avramchenko <oleksiy.avramchenko@...ymobile.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Joel Fernandes <joelaf@...gle.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...e.hu>, Tejun Heo <tj@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Stephen Rothwell <sfr@...b.auug.org.au>,
        Roman Penyaev <rpenyaev@...e.de>,
        Rick Edgecombe <rick.p.edgecombe@...el.com>,
        Andrey Ryabinin <aryabinin@...tuozzo.com>,
        Mike Rapoport <rppt@...ux.ibm.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Subject: [BUG]: mm/vmalloc: uninitialized variable access in pcpu_get_vm_areas

gcc points out some obviously broken code in linux-next

mm/vmalloc.c: In function 'pcpu_get_vm_areas':
mm/vmalloc.c:991:4: error: 'lva' may be used uninitialized in this function [-Werror=maybe-uninitialized]
    insert_vmap_area_augment(lva, &va->rb_node,
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     &free_vmap_area_root, &free_vmap_area_list);
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/vmalloc.c:916:20: note: 'lva' was declared here
  struct vmap_area *lva;
                    ^~~

Remove the obviously broken code. This is almost certainly
not the correct solution, but it's what I have applied locally
to get a clean build again.

Please fix this properly.

Fixes: 68ad4a330433 ("mm/vmalloc.c: keep track of free blocks for vmap allocation")
Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
 mm/vmalloc.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index a9213fc3802d..bfcf0124a773 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -984,14 +984,9 @@ adjust_va_to_fit_type(struct vmap_area *va,
 		return -1;
 	}
 
-	if (type != FL_FIT_TYPE) {
+	if (type == FL_FIT_TYPE)
 		augment_tree_propagate_from(va);
 
-		if (type == NE_FIT_TYPE)
-			insert_vmap_area_augment(lva, &va->rb_node,
-				&free_vmap_area_root, &free_vmap_area_list);
-	}
-
 	return 0;
 }
 
-- 
2.20.0