linux-kernel - [PATCH 1/3] shmem: fix tmpfs to handle the huge= option properly

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>] [day] [month] [year] [list]

Date:   Fri, 23 Sep 2016 20:21:56 -0700 (PDT)
From:   Hugh Dickins <hughd@...gle.com>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Toshi Kani <toshi.kani@....com>,
        Hillf Danton <hillf.zj@...baba-inc.com>,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        "Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: [PATCH 1/3] shmem: fix tmpfs to handle the huge= option properly

From: Toshi Kani <toshi.kani@....com>

shmem_get_unmapped_area() checks SHMEM_SB(sb)->huge incorrectly,
which leads to a reversed effect of "huge=" mount option.

Fix the check in shmem_get_unmapped_area().

Note, the default value of SHMEM_SB(sb)->huge remains as
SHMEM_HUGE_NEVER.  User will need to specify "huge=" option to
enable huge page mappings.

Reported-by: Hillf Danton <hillf.zj@...baba-inc.com>
Signed-off-by: Toshi Kani <toshi.kani@....com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@...ux.vnet.ibm.com>
Signed-off-by: Hugh Dickins <hughd@...gle.com>
---

 mm/shmem.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 4.8-rc7/mm/shmem.c	2016-08-14 20:17:02.388843463 -0700
+++ linux/mm/shmem.c	2016-09-22 19:41:29.057848626 -0700
@@ -1980,7 +1980,7 @@ unsigned long shmem_get_unmapped_area(st
 				return addr;
 			sb = shm_mnt->mnt_sb;
 		}
-		if (SHMEM_SB(sb)->huge != SHMEM_HUGE_NEVER)
+		if (SHMEM_SB(sb)->huge == SHMEM_HUGE_NEVER)
 			return addr;
 	}