From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: linux-sgx@vger.kernel.org
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
Haitao Huang <haitao.huang@linux.intel.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Jethro Beekman <jethro@fortanix.com>,
Matthew Wilcox <willy@infradead.org>,
Dave Hansen <dave.hansen@linux.intel.com>
Subject: [PATCH] x86/sgx: Fix sgx_encl_may_map locking
Date: Mon, 5 Oct 2020 03:41:20 +0300 [thread overview]
Message-ID: <20201005004120.105849-1-jarkko.sakkinen@linux.intel.com> (raw)
Fix the issue further discussed in:
1. https://lore.kernel.org/linux-sgx/op.0rwbv916wjvjmi@mqcpg7oapc828.gar.corp.intel.com/
2. https://lore.kernel.org/linux-sgx/20201003195440.GD20115@casper.infradead.org/
Reported-by: Haitao Huang <haitao.huang@linux.intel.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Jethro Beekman <jethro@fortanix.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
arch/x86/kernel/cpu/sgx/encl.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
index ae45f8f0951e..a225e96c7a39 100644
--- a/arch/x86/kernel/cpu/sgx/encl.c
+++ b/arch/x86/kernel/cpu/sgx/encl.c
@@ -304,11 +304,10 @@ int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
unsigned long end, unsigned long vm_flags)
{
unsigned long vm_prot_bits = vm_flags & (VM_READ | VM_WRITE | VM_EXEC);
- unsigned long idx_start = PFN_DOWN(start);
- unsigned long idx_end = PFN_DOWN(end - 1);
+ unsigned long start_i = PFN_DOWN(start);
+ unsigned long end_i = PFN_DOWN(end - 1);
struct sgx_encl_page *page;
-
- XA_STATE(xas, &encl->page_array, idx_start);
+ int i;
/*
* Disallow READ_IMPLIES_EXEC tasks as their VMA permissions might
@@ -317,9 +316,14 @@ int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
if (current->personality & READ_IMPLIES_EXEC)
return -EACCES;
- xas_for_each(&xas, page, idx_end)
+ for (i = start_i; i <= end_i; i++) {
+ mutex_lock(&encl->lock);
+ page = xa_load(&encl->page_array, i);
+ mutex_unlock(&encl->lock);
+
if (!page || (~page->vm_max_prot_bits & vm_prot_bits))
return -EACCES;
+ }
return 0;
}
--
2.25.1
next reply other threads:[~2020-10-05 0:41 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-05 0:41 Jarkko Sakkinen [this message]
2020-10-05 3:27 ` [PATCH] x86/sgx: Fix sgx_encl_may_map locking Haitao Huang
2020-10-05 3:43 ` Jarkko Sakkinen
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