[Pkg-gmagick-im-team] Bug#619134: Bug#619134: /usr/bin/display: Bus Error on EIO

[Meelis Roos]

> > mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)= 0x7feea7df3000
> > read(4, 0x7feea7df3000, 2048)           = -1 EIO (Input/output error)
> > lseek(4, 0, SEEK_SET)                   = 0
> > mmap(NULL, 8206, PROT_READ, MAP_PRIVATE, 4, 0) = 0x7feea7df0000
> > close(4)                                = 0
> > munmap(0x7feea7df3000, 4096)            = 0
> > --- SIGBUS (Bus error) @ 0 (0) ---
> > +++ killed by SIGBUS +++
> 
> SIGBUS after mumap an EIO file is not a imagemagick problem.
> 
> see http://linux.die.net/man/2/mmap and also
> http://mail.gnome.org/archives/mc-devel/2001-September/msg00104.html

Umm, yes, of course this is documented behaviour of mmap. But accessing 
the mmaped region after close and munmap is where I see the bug here. 
Use-after-free of sort. Am I wrong with this?

-- 
Meelis Roos (mroos at linux.ee)