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Revision 89a8640279f8bb78aaf778d1fc5c4a6778f18064 authored by David Howells on 30 October 2009, 13:13:26 UTC, committed by Linus Torvalds on 31 October 2009, 19:11:37 UTC 
NOMMU: Don't pass NULL pointers to fput() in do_mmap_pgoff()
 
Don't pass NULL pointers to fput() in the error handling paths of the NOMMU
do_mmap_pgoff() as it can't handle it.

The following can be used as a test program:

	int main() { static long long a[1024 * 1024 * 20] = { 0 }; return a;}

Without the patch, the code oopses in atomic_long_dec_and_test() as called by
fput() after the kernel complains that it can't allocate that big a chunk of
memory.  With the patch, the kernel just complains about the allocation size
and then the program segfaults during execve() as execve() can't complete the
allocation of all the new ELF program segments.

Reported-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Robin Getz <rgetz@blackfin.uclinux.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 2e2ec95
Raw File
mutex.h 
/*
 * Mutexes: blocking mutual exclusion locks
 *
 * started by Ingo Molnar:
 *
 *  Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 *
 * This file contains mutex debugging related internal prototypes, for the
 * !CONFIG_DEBUG_MUTEXES case. Most of them are NOPs:
 */

#define spin_lock_mutex(lock, flags) \
		do { spin_lock(lock); (void)(flags); } while (0)
#define spin_unlock_mutex(lock, flags) \
		do { spin_unlock(lock); (void)(flags); } while (0)
#define mutex_remove_waiter(lock, waiter, ti) \
		__list_del((waiter)->list.prev, (waiter)->list.next)

#ifdef CONFIG_SMP
static inline void mutex_set_owner(struct mutex *lock)
{
	lock->owner = current_thread_info();
}

static inline void mutex_clear_owner(struct mutex *lock)
{
	lock->owner = NULL;
}
#else
static inline void mutex_set_owner(struct mutex *lock)
{
}

static inline void mutex_clear_owner(struct mutex *lock)
{
}
#endif

#define debug_mutex_wake_waiter(lock, waiter)		do { } while (0)
#define debug_mutex_free_waiter(waiter)			do { } while (0)
#define debug_mutex_add_waiter(lock, waiter, ti)	do { } while (0)
#define debug_mutex_unlock(lock)			do { } while (0)
#define debug_mutex_init(lock, name, key)		do { } while (0)

static inline void
debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
}
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