diff options
| author | Kirill A. Shutemov <kirill@shutemov.name> | 2008-10-15 22:02:39 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-12-13 15:29:33 -0800 |
| commit | 0993210979a0ce0b25a1949fdbeeb07782747978 (patch) | |
| tree | 60d448e00f9fa0462c3fe466c5dda1b3f491311f /include | |
| parent | f8220954306c6fdc127a5ec645e825991fc97812 (diff) | |
| download | lwn-0993210979a0ce0b25a1949fdbeeb07782747978.tar.gz lwn-0993210979a0ce0b25a1949fdbeeb07782747978.zip | |
Allow recursion in binfmt_script and binfmt_misc
commit bf2a9a39639b8b51377905397a5005f444e9a892 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/binfmts.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index 826f62350805..12413a1e2784 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -36,6 +36,7 @@ struct linux_binprm{ unsigned long p; /* current top of mem */ unsigned int sh_bang:1, misc_bang:1; + unsigned int recursion_depth; struct file * file; int e_uid, e_gid; kernel_cap_t cap_post_exec_permitted; @@ -58,6 +59,7 @@ struct linux_binprm{ #define BINPRM_FLAGS_EXECFD_BIT 1 #define BINPRM_FLAGS_EXECFD (1 << BINPRM_FLAGS_EXECFD_BIT) +#define BINPRM_MAX_RECURSION 4 /* * This structure defines the functions that are used to load the binary formats that |