On Sun, Sep 9, 2018 at 8:41 PM, syzbot <syzbot+d86c4426a01f60feddc7@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: f8f65382c98a Merge tag 'for-linus' of git://git.kernel.org.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=113260ae400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=8f59875069d721b6 > dashboard link: https://syzkaller.appspot.com/bug?extid=d86c4426a01f60feddc7 > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=120baa9e400000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13979cbe400000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+d86c4426a01f60feddc7@xxxxxxxxxxxxxxxxxxxxxxxxx > > random: sshd: uninitialized urandom read (32 bytes read) > random: sshd: uninitialized urandom read (32 bytes read) > random: sshd: uninitialized urandom read (32 bytes read) > > ======================================================== > WARNING: possible irq lock inversion dependency detected > 4.19.0-rc2+ #229 Not tainted > -------------------------------------------------------- > swapper/0/0 just changed the state of lock: > 00000000c02bddef (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq > include/linux/spinlock.h:354 [inline] > 00000000c02bddef (&(&ctx->ctx_lock)->rlock){..-.}, at: > free_ioctx_users+0xbc/0x710 fs/aio.c:603 > but this lock took another, SOFTIRQ-unsafe lock in the past: > (&fiq->waitq){+.+.} > > > and interrupts could create inverse lock ordering between them. > > > other info that might help us debug this: > Possible interrupt unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(&fiq->waitq); > local_irq_disable(); > lock(&(&ctx->ctx_lock)->rlock); > lock(&fiq->waitq); > <Interrupt> > lock(&(&ctx->ctx_lock)->rlock); Fuse device doesn't support AIO ops. So false positive, AFAICS. Thanks, Miklos
