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authorWanpeng Li <liwanp@linux.vnet.ibm.com>2013-12-18 17:08:56 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-12-18 19:04:52 -0800
commit11c731e81bb0d8d2e835447a2dd645b34bb74706 (patch)
tree4e5b449243f1b0d55df6e87be2df5cad49722bc3
parent584ec9794293ff69f597f5bec23296e62e94e857 (diff)
downloadlinux-11c731e81bb0d8d2e835447a2dd645b34bb74706.tar.gz
mm/mempolicy: fix !vma in new_vma_page()
BUG_ON(!vma) assumption is introduced by commit 0bf598d863e3 ("mbind: add BUG_ON(!vma) in new_vma_page()"), however, even if address = __vma_address(page, vma); and vma->start < address < vma->end page_address_in_vma() may still return -EFAULT because of many other conditions in it. As a result the while loop in new_vma_page() may end with vma=NULL. This patch revert the commit and also fix the potential dereference NULL pointer reported by Dan. http://marc.info/?l=linux-mm&m=137689530323257&w=2 kernel BUG at mm/mempolicy.c:1204! invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC CPU: 3 PID: 7056 Comm: trinity-child3 Not tainted 3.13.0-rc3+ #2 task: ffff8801ca5295d0 ti: ffff88005ab20000 task.ti: ffff88005ab20000 RIP: new_vma_page+0x70/0x90 RSP: 0000:ffff88005ab21db0 EFLAGS: 00010246 RAX: fffffffffffffff2 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000008040075 RSI: ffff8801c3d74600 RDI: ffffea00079a8b80 RBP: ffff88005ab21dc8 R08: 0000000000000004 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: fffffffffffffff2 R13: ffffea00079a8b80 R14: 0000000000400000 R15: 0000000000400000 FS: 00007ff49c6f4740(0000) GS:ffff880244e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff49c68f994 CR3: 000000005a205000 CR4: 00000000001407e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffea00079a8b80 ffffea00079a8bc0 ffffea00079a8ba0 ffff88005ab21e50 ffffffff811adc7a 0000000000000000 ffff8801ca5295d0 0000000464e224f8 0000000000000000 0000000000000002 0000000000000000 ffff88020ce75c00 Call Trace: migrate_pages+0x12a/0x850 SYSC_mbind+0x513/0x6a0 SyS_mbind+0xe/0x10 ia32_do_call+0x13/0x13 Code: 85 c0 75 2f 4c 89 e1 48 89 da 31 f6 bf da 00 02 00 65 44 8b 04 25 08 f7 1c 00 e8 ec fd ff ff 5b 41 5c 41 5d 5d c3 0f 1f 44 00 00 <0f> 0b 66 0f 1f 44 00 00 4c 89 e6 48 89 df ba 01 00 00 00 e8 48 RIP [<ffffffff8119f200>] new_vma_page+0x70/0x90 RSP <ffff88005ab21db0> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reported-by: Dave Jones <davej@redhat.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/mempolicy.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 6d04d372be29..0cd2c4d4e270 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1197,14 +1197,16 @@ static struct page *new_vma_page(struct page *page, unsigned long private, int *
break;
vma = vma->vm_next;
}
+
+ if (PageHuge(page)) {
+ if (vma)
+ return alloc_huge_page_noerr(vma, address, 1);
+ else
+ return NULL;
+ }
/*
- * queue_pages_range() confirms that @page belongs to some vma,
- * so vma shouldn't be NULL.
+ * if !vma, alloc_page_vma() will use task or system default policy
*/
- BUG_ON(!vma);
-
- if (PageHuge(page))
- return alloc_huge_page_noerr(vma, address, 1);
return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
}
#else