From 291681ad101fe7fc68cb0f875b3e39aa5e8e8f37 Mon Sep 17 00:00:00 2001
From: Reid Barton <rwbarton@gmail.com>
Date: Tue, 1 Jul 2014 10:20:31 -0400
Subject: [PATCH] Check for integer overflow in allocate() (#9172)
Summary: Check for integer overflow in allocate() (#9172)
Test Plan: validate
Reviewers: austin
Reviewed By: austin
Subscribers: simonmar, relrod, carter
Differential Revision: https://phabricator.haskell.org/D36
(cherry picked from commit db64180896b395283f443d66a308048c605b217d)
Conflicts:
testsuite/.gitignore
---
rts/sm/Storage.c | 10 +++++++++-
testsuite/tests/rts/all.T | 5 +++++
testsuite/tests/rts/overflow1.hs | 11 +++++++++++
testsuite/tests/rts/overflow1.stderr | 1 +
testsuite/tests/rts/overflow2.hs | 20 ++++++++++++++++++++
testsuite/tests/rts/overflow2.stderr | 1 +
testsuite/tests/rts/overflow3.hs | 20 ++++++++++++++++++++
testsuite/tests/rts/overflow3.stderr | 1 +
8 files changed, 68 insertions(+), 1 deletion(-)
create mode 100644 testsuite/tests/rts/overflow1.hs
create mode 100644 testsuite/tests/rts/overflow1.stderr
create mode 100644 testsuite/tests/rts/overflow2.hs
create mode 100644 testsuite/tests/rts/overflow2.stderr
create mode 100644 testsuite/tests/rts/overflow3.hs
create mode 100644 testsuite/tests/rts/overflow3.stderr
diff --git a/rts/sm/Storage.c b/rts/sm/Storage.c
index 86bd1c2bb364..d002fece9c6e 100644
--- a/rts/sm/Storage.c
+++ b/rts/sm/Storage.c
@@ -686,7 +686,15 @@ StgPtr allocate (Capability *cap, W_ n)
CCS_ALLOC(cap->r.rCCCS,n);
if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_)) {
- W_ req_blocks = (W_)BLOCK_ROUND_UP(n*sizeof(W_)) / BLOCK_SIZE;
+ // The largest number of bytes such that
+ // the computation of req_blocks will not overflow.
+ W_ max_bytes = (HS_WORD_MAX & ~(BLOCK_SIZE-1)) / sizeof(W_);
+ W_ req_blocks;
+
+ if (n > max_bytes)
+ req_blocks = HS_WORD_MAX; // signal overflow below
+ else
+ req_blocks = (W_)BLOCK_ROUND_UP(n*sizeof(W_)) / BLOCK_SIZE;
// Attempting to allocate an object larger than maxHeapSize
// should definitely be disallowed. (bug #1791)
diff --git a/testsuite/tests/rts/all.T b/testsuite/tests/rts/all.T
index 8b4fdfa1cc98..920368a0e32f 100644
--- a/testsuite/tests/rts/all.T
+++ b/testsuite/tests/rts/all.T
@@ -215,3 +215,8 @@ test('T9045', [ omit_ways(['ghci']), extra_run_opts('10000 +RTS -A8k -RTS') ], c
# I couldn't reproduce 9078 with the -threaded runtime, but could easily
# with the non-threaded one.
test('T9078', [ omit_ways(threaded_ways) ], compile_and_run, ['-with-rtsopts="-DS" -debug'])
+
+# 251 = RTS exit code for "out of memory"
+test('overflow1', [ exit_code(251) ], compile_and_run, [''])
+test('overflow2', [ exit_code(251) ], compile_and_run, [''])
+test('overflow3', [ exit_code(251) ], compile_and_run, [''])
diff --git a/testsuite/tests/rts/overflow1.hs b/testsuite/tests/rts/overflow1.hs
new file mode 100644
index 000000000000..63ed5a4e0240
--- /dev/null
+++ b/testsuite/tests/rts/overflow1.hs
@@ -0,0 +1,11 @@
+module Main where
+
+import Data.Array.IO
+import Data.Word
+
+-- Try to overflow BLOCK_ROUND_UP in the computation of req_blocks in allocate()
+-- Here we invoke allocate() via newByteArray# and the array package.
+-- Request a number of bytes close to HS_WORD_MAX,
+-- subtracting a few words for overhead in newByteArray#.
+-- Allocate Word32s (rather than Word8s) to get around bounds-checking in array.
+main = newArray (0,maxBound `div` 4 - 10) 0 :: IO (IOUArray Word Word32)
diff --git a/testsuite/tests/rts/overflow1.stderr b/testsuite/tests/rts/overflow1.stderr
new file mode 100644
index 000000000000..734ca954cad5
--- /dev/null
+++ b/testsuite/tests/rts/overflow1.stderr
@@ -0,0 +1 @@
+overflow1: out of memory
diff --git a/testsuite/tests/rts/overflow2.hs b/testsuite/tests/rts/overflow2.hs
new file mode 100644
index 000000000000..ac72158f454a
--- /dev/null
+++ b/testsuite/tests/rts/overflow2.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+module Main where
+
+import Foreign
+
+-- Test allocate(), the easy way.
+data Cap = Cap
+foreign import ccall "rts_unsafeGetMyCapability" myCapability :: IO (Ptr Cap)
+foreign import ccall "allocate" allocate :: Ptr Cap -> Word -> IO (Ptr ())
+
+-- Number of words n such that n * sizeof(W_) exactly overflows a word
+-- (2^30 on a 32-bit system, 2^61 on a 64-bit system)
+overflowWordCount :: Word
+overflowWordCount = fromInteger $
+ (fromIntegral (maxBound :: Word) + 1) `div`
+ fromIntegral (sizeOf (undefined :: Word))
+
+main = do
+ cap <- myCapability
+ allocate cap (overflowWordCount - 1)
diff --git a/testsuite/tests/rts/overflow2.stderr b/testsuite/tests/rts/overflow2.stderr
new file mode 100644
index 000000000000..be65509ea928
--- /dev/null
+++ b/testsuite/tests/rts/overflow2.stderr
@@ -0,0 +1 @@
+overflow2: out of memory
diff --git a/testsuite/tests/rts/overflow3.hs b/testsuite/tests/rts/overflow3.hs
new file mode 100644
index 000000000000..31dfd5db53e7
--- /dev/null
+++ b/testsuite/tests/rts/overflow3.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+module Main where
+
+import Foreign
+
+-- Test allocate(), the easy way.
+data Cap = Cap
+foreign import ccall "rts_unsafeGetMyCapability" myCapability :: IO (Ptr Cap)
+foreign import ccall "allocate" allocate :: Ptr Cap -> Word -> IO (Ptr ())
+
+-- Number of words n such that n * sizeof(W_) exactly overflows a word
+-- (2^30 on a 32-bit system, 2^61 on a 64-bit system)
+overflowWordCount :: Word
+overflowWordCount = fromInteger $
+ (fromIntegral (maxBound :: Word) + 1) `div`
+ fromIntegral (sizeOf (undefined :: Word))
+
+main = do
+ cap <- myCapability
+ allocate cap (overflowWordCount + 1)
diff --git a/testsuite/tests/rts/overflow3.stderr b/testsuite/tests/rts/overflow3.stderr
new file mode 100644
index 000000000000..6c804e504896
--- /dev/null
+++ b/testsuite/tests/rts/overflow3.stderr
@@ -0,0 +1 @@
+overflow3: out of memory
--
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