On Tue, Oct 20, 2015 at 01:26:01PM -0700, Kees Cook wrote: > On Tue, Oct 20, 2015 at 1:20 PM, Oleg Nesterov <oleg@xxxxxxxxxx> wrote: > > > > Oh wait, I didn't notice this when I looked at v7. > > > > No, you can't do copy_to_user() from atomic context. You need to pin this > > filter, drop the lock/irq, then copy_to_user(). > > Which CONFIGs would yell about this? CONFIG_DEBUG_ATOMIC_SLEEP? Yep, it seems to, Oct 20 14:35:55 kernel kernel: [ 17.879492] BUG: sleeping function called from invalid context at ./arch/x86/include/asm/uaccess.h:732 Oct 20 14:35:55 kernel kernel: [ 17.880925] in_atomic(): 1, irqs_disabled(): 1, pid: 2023, name: criu Oct 20 14:35:55 kernel kernel: [ 17.881913] CPU: 2 PID: 2023 Comm: criu Not tainted 4.3.0-rc3+ #11 Oct 20 14:35:55 kernel kernel: [ 17.881915] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 Oct 20 14:35:55 kernel kernel: [ 17.881916] 00000000000002dc ffff880078ca7dc8 ffffffff8133605d ffff880078819780 Oct 20 14:35:55 kernel kernel: [ 17.881920] ffff880078ca7de0 ffffffff81077b3f ffffffff81baf4a0 ffff880078ca7e08 Oct 20 14:35:55 kernel kernel: [ 17.881922] ffffffff81077bc4 00007ffe1570c420 ffff8800798bb460 0000000000000004 Oct 20 14:35:55 kernel kernel: [ 17.881924] Call Trace: Oct 20 14:35:55 kernel kernel: [ 17.881932] [<ffffffff8133605d>] dump_stack+0x4b/0x6e Oct 20 14:35:55 kernel kernel: [ 17.881940] [<ffffffff81077b3f>] ___might_sleep+0xcf/0x110 Oct 20 14:35:55 kernel kernel: [ 17.881943] [<ffffffff81077bc4>] __might_sleep+0x44/0x80 Oct 20 14:35:55 kernel kernel: [ 17.881950] [<ffffffff8114b2f2>] __might_fault+0x32/0x40 Oct 20 14:35:55 kernel kernel: [ 17.881956] [<ffffffff810eadc5>] seccomp_get_filter+0x115/0x170 Oct 20 14:35:55 kernel kernel: [ 17.881961] [<ffffffff8105f483>] ptrace_request+0x73/0x5d0 Oct 20 14:35:55 kernel kernel: [ 17.881969] [<ffffffff81182698>] ? __fput+0x188/0x1f0 Oct 20 14:35:55 kernel kernel: [ 17.881980] [<ffffffff818ddf29>] ? _raw_spin_unlock_irqrestore+0x9/0x10 Oct 20 14:35:55 kernel kernel: [ 17.881983] [<ffffffff8107c30c>] ? wait_task_inactive+0xfc/0x1f0 Oct 20 14:35:55 kernel kernel: [ 17.881986] [<ffffffff810490ea>] ? __do_page_fault+0x1ca/0x410 Oct 20 14:35:55 kernel kernel: [ 17.881990] [<ffffffff81011d94>] arch_ptrace+0x2a4/0x320 Oct 20 14:35:55 kernel kernel: [ 17.881993] [<ffffffff8105f32a>] SyS_ptrace+0x7a/0x100 Oct 20 14:35:55 kernel kernel: [ 17.881996] [<ffffffff818de4ae>] entry_SYSCALL_64_fastpath+0x12/0x71 Thanks, Oleg. I'll make the change and re-send. Tycho -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
