Revision 00d6058ac93048b525b86fa48b413dcb87ac2728 authored by Ian Abbott on 26 June 2006, 10:44:22 UTC, committed by Greg Kroah-Hartman on 12 July 2006, 23:03:22 UTC
The anti user-DoS mechanism in the USB serial 'visor' driver can fail in the following way: visor_open: priv->outstanding_urbs = 0 visor_write: ++priv->outstanding_urbs visor_close: visor_open: priv->outstanding_urbs = 0 visor_write_bulk_callback: --priv->outstanding_urbs So priv->outstanding_urbs ends up as (unsigned long)(-1). Not good! I haven't seen this happen with the visor driver as I don't have the hardware, but I have seen it while testing a patch to implement the same functionality in the ftdi_sio driver (patch not yet submitted). The fix is pretty simple: don't reinitialize outstanding_urbs in visor_open. (Again, I haven't tested the fix in visor, but I have tested it in ftdi_sio.) Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
1 parent 5650b4d
mutex-debug.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 declarations,
* prototypes and inline functions, for the CONFIG_DEBUG_MUTEXES case.
* More details are in kernel/mutex-debug.c.
*/
/*
* This must be called with lock->wait_lock held.
*/
extern void
debug_mutex_set_owner(struct mutex *lock, struct thread_info *new_owner);
static inline void debug_mutex_clear_owner(struct mutex *lock)
{
lock->owner = NULL;
}
extern void debug_mutex_lock_common(struct mutex *lock,
struct mutex_waiter *waiter);
extern void debug_mutex_wake_waiter(struct mutex *lock,
struct mutex_waiter *waiter);
extern void debug_mutex_free_waiter(struct mutex_waiter *waiter);
extern void debug_mutex_add_waiter(struct mutex *lock,
struct mutex_waiter *waiter,
struct thread_info *ti);
extern void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
struct thread_info *ti);
extern void debug_mutex_unlock(struct mutex *lock);
extern void debug_mutex_init(struct mutex *lock, const char *name,
struct lock_class_key *key);
#define spin_lock_mutex(lock, flags) \
do { \
struct mutex *l = container_of(lock, struct mutex, wait_lock); \
\
DEBUG_LOCKS_WARN_ON(in_interrupt()); \
local_irq_save(flags); \
__raw_spin_lock(&(lock)->raw_lock); \
DEBUG_LOCKS_WARN_ON(l->magic != l); \
} while (0)
#define spin_unlock_mutex(lock, flags) \
do { \
__raw_spin_unlock(&(lock)->raw_lock); \
local_irq_restore(flags); \
preempt_check_resched(); \
} while (0)
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