From 10f0138c56a31a39c2a123af5af95cf8fd5de1ac Mon Sep 17 00:00:00 2001 From: Erik Gilling Date: Tue, 25 Aug 2009 20:09:12 -0700 Subject: [PATCH] power: wakelocks: fix buffer overflow in print_wake_locks Change-Id: Ic944e3b3d3bc53eddc6fd0963565fd072cac373c Signed-off-by: Erik Gilling --- kernel/power/wakelock.c | 44 +++++++++++++++++++++++------------------ 1 file changed, 25 insertions(+), 19 deletions(-) diff --git a/kernel/power/wakelock.c b/kernel/power/wakelock.c index 62714d75c3c9..263de24f8019 100644 --- a/kernel/power/wakelock.c +++ b/kernel/power/wakelock.c @@ -40,6 +40,8 @@ module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP); #define WAKE_LOCK_AUTO_EXPIRE (1U << 10) #define WAKE_LOCK_PREVENTING_SUSPEND (1U << 11) +#define TOO_MAY_LOCKS_WARNING "\n\ntoo many wakelocks!!!\n" + static DEFINE_SPINLOCK(list_lock); static LIST_HEAD(inactive_locks); static struct list_head active_wake_locks[WAKE_LOCK_TYPE_COUNT]; @@ -81,13 +83,15 @@ int get_expired_time(struct wake_lock *lock, ktime_t *expire_time) } -static int print_lock_stat(char *buf, struct wake_lock *lock) +static int print_lock_stat(char *buf, int len, struct wake_lock *lock) { int lock_count = lock->stat.count; int expire_count = lock->stat.expire_count; ktime_t active_time = ktime_set(0, 0); ktime_t total_time = lock->stat.total_time; ktime_t max_time = lock->stat.max_time; + int n; + ktime_t prevent_suspend_time = lock->stat.prevent_suspend_time; if (lock->flags & WAKE_LOCK_ACTIVE) { ktime_t now, add_time; @@ -108,12 +112,15 @@ static int print_lock_stat(char *buf, struct wake_lock *lock) max_time = add_time; } - return sprintf(buf, "\"%s\"\t%d\t%d\t%d\t%lld\t%lld\t%lld\t%lld\t" - "%lld\n", lock->name, lock_count, expire_count, - lock->stat.wakeup_count, ktime_to_ns(active_time), - ktime_to_ns(total_time), - ktime_to_ns(prevent_suspend_time), ktime_to_ns(max_time), - ktime_to_ns(lock->stat.last_time)); + n = snprintf(buf, len, + "\"%s\"\t%d\t%d\t%d\t%lld\t%lld\t%lld\t%lld\t%lld\n", + lock->name, lock_count, expire_count, + lock->stat.wakeup_count, ktime_to_ns(active_time), + ktime_to_ns(total_time), + ktime_to_ns(prevent_suspend_time), ktime_to_ns(max_time), + ktime_to_ns(lock->stat.last_time)); + + return n > len ? len : n; } @@ -123,31 +130,30 @@ static int wakelocks_read_proc(char *page, char **start, off_t off, unsigned long irqflags; struct wake_lock *lock; int len = 0; - char *p = page; int type; spin_lock_irqsave(&list_lock, irqflags); - p += sprintf(p, "name\tcount\texpire_count\twake_count\tactive_since" - "\ttotal_time\tsleep_time\tmax_time\tlast_change\n"); + len += snprintf(page + len, count - len, + "name\tcount\texpire_count\twake_count\tactive_since" + "\ttotal_time\tsleep_time\tmax_time\tlast_change\n"); list_for_each_entry(lock, &inactive_locks, link) { - p += print_lock_stat(p, lock); + len += print_lock_stat(page + len, count - len, lock); } for (type = 0; type < WAKE_LOCK_TYPE_COUNT; type++) { list_for_each_entry(lock, &active_wake_locks[type], link) - p += print_lock_stat(p, lock); + len += print_lock_stat(page + len, count - len, lock); } spin_unlock_irqrestore(&list_lock, irqflags); - *start = page + off; + if (len == count) + memcpy(page + len - strlen(TOO_MAY_LOCKS_WARNING), + TOO_MAY_LOCKS_WARNING, + strlen(TOO_MAY_LOCKS_WARNING)); - len = p - page; - if (len > off) - len -= off; - else - len = 0; + *eof = 1; - return len < count ? len : count; + return len; } static void wake_unlock_stat_locked(struct wake_lock *lock, int expired) -- 2.34.1