Re: possible deadlock in proc_pid_syscall (2)

2020-09-02 Thread peterz
On Sun, Aug 30, 2020 at 07:31:39AM -0500, Eric W. Biederman wrote: > pet...@infradead.org writes: > > Could we check privs twice instead? > > > > Something like the completely untested below.. > > That might work. > > I am thinking that for cases where we want to do significant work it > might

Re: possible deadlock in proc_pid_syscall (2)

2020-08-31 Thread Eric W. Biederman
pet...@infradead.org writes: > On Sun, Aug 30, 2020 at 07:31:39AM -0500, Eric W. Biederman wrote: > >> I am thinking that for cases where we want to do significant work it >> might be better to ask the process to pause at someplace safe (probably >> get_signal) and then do all of the work when we

Re: possible deadlock in proc_pid_syscall (2)

2020-08-31 Thread peterz
On Sun, Aug 30, 2020 at 07:31:39AM -0500, Eric W. Biederman wrote: > I am thinking that for cases where we want to do significant work it > might be better to ask the process to pause at someplace safe (probably > get_signal) and then do all of the work when we know nothing is changing > in the

Re: possible deadlock in proc_pid_syscall (2)

2020-08-30 Thread Eric W. Biederman
pet...@infradead.org writes: > On Fri, Aug 28, 2020 at 07:01:17AM -0500, Eric W. Biederman wrote: >> This feels like an issue where perf can just do too much under >> exec_update_mutex. In particular calling kern_path from >> create_local_trace_uprobe. Calling into the vfs at the very least >>

Re: possible deadlock in proc_pid_syscall (2)

2020-08-28 Thread peterz
On Fri, Aug 28, 2020 at 07:01:17AM -0500, Eric W. Biederman wrote: > This feels like an issue where perf can just do too much under > exec_update_mutex. In particular calling kern_path from > create_local_trace_uprobe. Calling into the vfs at the very least > makes it impossible to know exactly

Re: possible deadlock in proc_pid_syscall (2)

2020-08-28 Thread Eric W. Biederman
syzbot writes: > Hello, > > syzbot found the following issue on: > > HEAD commit:15bc20c6 Merge tag 'tty-5.9-rc3' of git://git.kernel.org/p.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=15349f9690 > kernel config:

possible deadlock in proc_pid_syscall (2)

2020-08-27 Thread syzbot
Hello, syzbot found the following issue on: HEAD commit:15bc20c6 Merge tag 'tty-5.9-rc3' of git://git.kernel.org/p.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15349f9690 kernel config: https://syzkaller.appspot.com/x/.config?x=978db74cb30aa994