linux/include
Kees Cook d740269867 exec: use -ELOOP for max recursion depth
To avoid an explosion of request_module calls on a chain of abusive
scripts, fail maximum recursion with -ELOOP instead of -ENOEXEC. As soon
as maximum recursion depth is hit, the error will fail all the way back
up the chain, aborting immediately.

This also has the side-effect of stopping the user's shell from attempting
to reexecute the top-level file as a shell script. As seen in the
dash source:

        if (cmd != path_bshell && errno == ENOEXEC) {
                *argv-- = cmd;
                *argv = cmd = path_bshell;
                goto repeat;
        }

The above logic was designed for running scripts automatically that lacked
the "#!" header, not to re-try failed recursion. On a legitimate -ENOEXEC,
things continue to behave as the shell expects.

Additionally, when tracking recursion, the binfmt handlers should not be
involved. The recursion being tracked is the depth of calls through
search_binary_handler(), so that function should be exclusively responsible
for tracking the depth.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: halfdog <me@halfdog.net>
Cc: P J P <ppandit@redhat.com>
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>
2012-12-17 17:15:23 -08:00
..
acpi PCI changes for the v3.8 merge window: 2012-12-13 12:14:47 -08:00
asm-generic asm-generic: io: don't perform swab during {in,out} string functions 2012-12-17 17:15:13 -08:00
clocksource
crypto crypto: cast5/cast6 - move lookup tables to shared module 2012-12-06 17:16:26 +08:00
drm Merge branch 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel into drm-next 2012-12-16 06:05:03 +00:00
keys
linux exec: use -ELOOP for max recursion depth 2012-12-17 17:15:23 -08:00
math-emu
media [media] V4L: Add driver for S3C24XX/S3C64XX SoC series camera interface 2012-11-28 09:43:34 -02:00
memory
misc
net Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-12-13 12:00:02 -08:00
pcmcia
ras
rdma UAPI: (Scripted) Disintegrate include/rdma 2012-11-22 00:43:10 -08:00
rxrpc
scsi SCSI misc on 20121212 2012-12-13 19:20:31 -08:00
sound Merge remote-tracking branch 'asoc/topic/tlv320aic32x4' into asoc-next 2012-12-10 00:22:20 +09:00
target target/iscsi_target: Add NodeACL tags for initiator group support 2012-12-13 14:18:09 -08:00
trace There are two major features for this merge window. The first is 2012-12-16 17:33:01 -08:00
uapi ptrace: introduce PTRACE_O_EXITKILL 2012-12-17 17:15:22 -08:00
video Merge tag 'omapdss-for-3.8' of git://gitorious.org/linux-omap-dss2/linux into for-linus 2012-12-13 14:30:56 +02:00
xen Features: 2012-12-13 14:29:16 -08:00
Kbuild