From: Oleg Nesterov Date: Sun, 18 Jan 2009 17:17:20 +0000 (+0100) Subject: Staging: android: task_get_unused_fd_flags: fix the wrong usage of tsk->signal X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=1176e83aff6f15b6ae4d1b53c16124884ad29363;p=linux-2.6-omap-h63xx.git Staging: android: task_get_unused_fd_flags: fix the wrong usage of tsk->signal Compile tested. task_struct->signal is not protected by RCU, the code is bogus. Change the code to take ->siglock to pin ->signal. Signed-off-by: Oleg Nesterov Cc: Arve Hjønnevåg Cc: Brian Swetland Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c index ab014bc9683..758131cad08 100644 --- a/drivers/staging/android/binder.c +++ b/drivers/staging/android/binder.c @@ -319,6 +319,7 @@ int task_get_unused_fd_flags(struct task_struct *tsk, int flags) int fd, error; struct fdtable *fdt; unsigned long rlim_cur; + unsigned long irqs; if (files == NULL) return -ESRCH; @@ -335,12 +336,11 @@ repeat: * N.B. For clone tasks sharing a files structure, this test * will limit the total number of files that can be opened. */ - rcu_read_lock(); - if (tsk->signal) + rlim_cur = 0; + if (lock_task_sighand(tsk, &irqs)) { rlim_cur = tsk->signal->rlim[RLIMIT_NOFILE].rlim_cur; - else - rlim_cur = 0; - rcu_read_unlock(); + unlock_task_sighand(tsk, &irqs); + } if (fd >= rlim_cur) goto out;