linux-kernel - [PATCH] Fix generic hugetlb pte check return type.

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: <20131002.142509.1450460988268165850.davem@davemloft.net>
Date:	Wed, 02 Oct 2013 14:25:09 -0400 (EDT)
From:	David Miller <davem@...emloft.net>
To:	sparclinux@...r.kernel.org
CC:	linux-arch@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] Fix generic hugetlb pte check return type.

The include/asm-generic/hugetlb.h stubs that just vector huge_pte_*()
calls to the pte_*() implementations won't work in certain situations.

x86 and sparc, for example, return "unsigned long" from the bit
checks, and just go "return pte_val(pte) & PTE_BIT_FOO;"

But since huge_pte_*() returns 'int', if any high bits on 64-bit are
relevant, they get chopped off.

The net effect is that we can loop forever trying to COW a huge page,
because the huge_pte_write() check signals false all the time.

Reported-by: Gurudas Pai <gurudas.pai@...cle.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
---

Anyone mind if I push this through the sparc tree?

diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
index d06079c..99b490b 100644
--- a/include/asm-generic/hugetlb.h
+++ b/include/asm-generic/hugetlb.h
@@ -6,12 +6,12 @@ static inline pte_t mk_huge_pte(struct page *page, pgprot_t pgprot)
 	return mk_pte(page, pgprot);
 }

-static inline int huge_pte_write(pte_t pte)
+static inline unsigned long huge_pte_write(pte_t pte)
 {
 	return pte_write(pte);
 }

-static inline int huge_pte_dirty(pte_t pte)
+static inline unsigned long huge_pte_dirty(pte_t pte)
 {
 	return pte_dirty(pte);
 }
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/