forked from Minki/linux
24ec839c43
Fix the locking of signal->tty.
Use ->sighand->siglock to protect ->signal->tty; this lock is already used
by most other members of ->signal/->sighand. And unless we are 'current'
or the tasklist_lock is held we need ->siglock to access ->signal anyway.
(NOTE: sys_unshare() is broken wrt ->sighand locking rules)
Note that tty_mutex is held over tty destruction, so while holding
tty_mutex any tty pointer remains valid. Otherwise the lifetime of ttys
are governed by their open file handles. This leaves some holes for tty
access from signal->tty (or any other non file related tty access).
It solves the tty SLAB scribbles we were seeing.
(NOTE: the change from group_send_sig_info to __group_send_sig_info needs to
be examined by someone familiar with the security framework, I think
it is safe given the SEND_SIG_PRIV from other __group_send_sig_info
invocations)
[schwidefsky@de.ibm.com: 3270 fix]
[akpm@osdl.org: various post-viro fixes]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Alan Cox <alan@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
90 lines
1.9 KiB
C
90 lines
1.9 KiB
C
/*
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* Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
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* Licensed under the GPL
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*/
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#include "linux/slab.h"
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#include "linux/smp_lock.h"
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#include "linux/ptrace.h"
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#include "asm/ptrace.h"
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#include "asm/pgtable.h"
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#include "asm/tlbflush.h"
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#include "asm/uaccess.h"
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#include "user_util.h"
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#include "kern_util.h"
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#include "mem_user.h"
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#include "kern.h"
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#include "irq_user.h"
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#include "tlb.h"
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#include "os.h"
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#include "choose-mode.h"
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#include "mode_kern.h"
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void flush_thread(void)
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{
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arch_flush_thread(¤t->thread.arch);
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CHOOSE_MODE(flush_thread_tt(), flush_thread_skas());
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}
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void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp)
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{
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CHOOSE_MODE_PROC(start_thread_tt, start_thread_skas, regs, eip, esp);
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}
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#ifdef CONFIG_TTY_LOG
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extern void log_exec(char **argv, void *tty);
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#endif
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static long execve1(char *file, char __user * __user *argv,
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char __user *__user *env)
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{
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long error;
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struct tty_struct *tty;
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#ifdef CONFIG_TTY_LOG
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mutex_lock(&tty_mutex);
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tty = get_current_tty();
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if (tty)
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log_exec(argv, tty);
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mutex_unlock(&tty_mutex);
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#endif
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error = do_execve(file, argv, env, ¤t->thread.regs);
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if (error == 0){
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task_lock(current);
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current->ptrace &= ~PT_DTRACE;
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#ifdef SUBARCH_EXECVE1
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SUBARCH_EXECVE1(¤t->thread.regs.regs);
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#endif
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task_unlock(current);
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set_cmdline(current_cmd());
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}
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return(error);
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}
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long um_execve(char *file, char __user *__user *argv, char __user *__user *env)
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{
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long err;
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err = execve1(file, argv, env);
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if(!err)
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do_longjmp(current->thread.exec_buf, 1);
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return(err);
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}
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long sys_execve(char __user *file, char __user *__user *argv,
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char __user *__user *env)
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{
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long error;
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char *filename;
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lock_kernel();
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filename = getname(file);
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error = PTR_ERR(filename);
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if (IS_ERR(filename)) goto out;
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error = execve1(filename, argv, env);
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putname(filename);
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out:
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unlock_kernel();
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return(error);
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}
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