Allow recursion in binfmt_script and binfmt_misc
binfmt_script and binfmt_misc disallow recursion to avoid stack overflow
using sh_bang and misc_bang. It causes problem in some cases:
$ echo '#!/bin/ls' > /tmp/t0
$ echo '#!/tmp/t0' > /tmp/t1
$ echo '#!/tmp/t1' > /tmp/t2
$ chmod +x /tmp/t*
$ /tmp/t2
zsh: exec format error: /tmp/t2
Similar problem with binfmt_misc.
This patch introduces field 'recursion_depth' into struct linux_binprm to
track recursion level in binfmt_misc and binfmt_script. If recursion
level more then BINPRM_MAX_RECURSION it generates -ENOEXEC.
[akpm@linux-foundation.org: make linux_binprm.recursion_depth a uint]
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 files changed