diff options
author | Mike Lockwood <lockwood@android.com> | 2009-07-02 13:25:00 -0400 |
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committer | Mike Lockwood <lockwood@android.com> | 2009-07-02 13:25:00 -0400 |
commit | 617750604c69e6068f68266d0e30324273aa990e (patch) | |
tree | a569ed7afdd79e388815f3e5608b1a0509269afe /wifi/java/android | |
parent | eec11827a6c06b029030f43c8d54fd871cc3347d (diff) | |
download | frameworks_base-617750604c69e6068f68266d0e30324273aa990e.zip frameworks_base-617750604c69e6068f68266d0e30324273aa990e.tar.gz frameworks_base-617750604c69e6068f68266d0e30324273aa990e.tar.bz2 |
WifiManager: Limit the number of WifiLocks that can be active simultaneously.
This is to prevent a bad app from using up all the global references in the
system process due to allocating too many DeathRecipients.
Signed-off-by: Mike Lockwood <lockwood@android.com>
Diffstat (limited to 'wifi/java/android')
-rw-r--r-- | wifi/java/android/net/wifi/WifiManager.java | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/wifi/java/android/net/wifi/WifiManager.java b/wifi/java/android/net/wifi/WifiManager.java index 5b8ced6..7a15f27 100644 --- a/wifi/java/android/net/wifi/WifiManager.java +++ b/wifi/java/android/net/wifi/WifiManager.java @@ -253,6 +253,15 @@ public class WifiManager { IWifiManager mService; Handler mHandler; + /* Maximum number of active locks we allow. + * This limit was added to prevent apps from creating a ridiculous number + * of locks and crashing the system by overflowing the global ref table. + */ + private static final int MAX_ACTIVE_LOCKS = 50; + + /* Number of currently active WifiLocks and MulticastLocks */ + private int mActiveLockCount; + /** * Create a new WifiManager instance. * Applications will almost always want to use @@ -702,6 +711,14 @@ public class WifiManager { if (mRefCounted ? (++mRefCount > 0) : (!mHeld)) { try { mService.acquireWifiLock(mBinder, mLockType, mTag); + synchronized (WifiManager.this) { + if (mActiveLockCount >= MAX_ACTIVE_LOCKS) { + mService.releaseWifiLock(mBinder); + throw new UnsupportedOperationException( + "Exceeded maximum number of wifi locks"); + } + mActiveLockCount++; + } } catch (RemoteException ignore) { } mHeld = true; @@ -726,6 +743,9 @@ public class WifiManager { if (mRefCounted ? (--mRefCount == 0) : (mHeld)) { try { mService.releaseWifiLock(mBinder); + synchronized (WifiManager.this) { + mActiveLockCount--; + } } catch (RemoteException ignore) { } mHeld = false; @@ -783,6 +803,9 @@ public class WifiManager { if (mHeld) { try { mService.releaseWifiLock(mBinder); + synchronized (WifiManager.this) { + mActiveLockCount--; + } } catch (RemoteException ignore) { } } @@ -877,6 +900,14 @@ public class WifiManager { if (!mHeld) { try { mService.acquireMulticastLock(mBinder, mTag); + synchronized (WifiManager.this) { + if (mActiveLockCount >= MAX_ACTIVE_LOCKS) { + mService.releaseMulticastLock(); + throw new UnsupportedOperationException( + "Exceeded maximum number of wifi locks"); + } + mActiveLockCount++; + } mHeld = true; } catch (RemoteException ignore) { } @@ -901,6 +932,9 @@ public class WifiManager { if (mHeld) { try { mService.releaseMulticastLock(); + synchronized (WifiManager.this) { + mActiveLockCount--; + } mHeld = false; } catch (RemoteException ignore) { } |