linux-stable.git/arch/alpha/kernel, branch v3.2.92

mm: larger stack guard gap, between vmas

2017-07-02T16:12:47+00:00

commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream.

Stack guard page is a useful feature to reduce a risk of stack smashing
into a different mapping. We have been using a single page gap which
is sufficient to prevent having stack adjacent to a different mapping.
But this seems to be insufficient in the light of the stack usage in
userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
which is 256kB or stack strings with MAX_ARG_STRLEN.

This will become especially dangerous for suid binaries and the default
no limit for the stack size limit because those applications can be
tricked to consume a large portion of the stack and a single glibc call
could jump over the guard page. These attacks are not theoretical,
unfortunatelly.

Make those attacks less probable by increasing the stack guard gap
to 1MB (on systems with 4k pages; but make it depend on the page size
because systems with larger base pages might cap stack allocations in
the PAGE_SIZE units) which should cover larger alloca() and VLA stack
allocations. It is obviously not a full fix because the problem is
somehow inherent, but it should reduce attack space a lot.

One could argue that the gap size should be configurable from userspace,
but that can be done later when somebody finds that the new 1MB is wrong
for some special case applications.  For now, add a kernel command line
option (stack_guard_gap) to specify the stack gap size (in page units).

Implementation wise, first delete all the old code for stack guard page:
because although we could get away with accounting one extra page in a
stack vma, accounting a larger gap can break userspace - case in point,
a program run with "ulimit -S -v 20000" failed when the 1MB gap was
counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
and strict non-overcommit mode.

Instead of keeping gap inside the stack vma, maintain the stack guard
gap as a gap between vmas: using vm_start_gap() in place of vm_start
(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
places which need to respect the gap - mainly arch_get_unmapped_area(),
and and the vma tree's subtree_gap support for that.

Original-patch-by: Oleg Nesterov 
Original-patch-by: Michal Hocko 
Signed-off-by: Hugh Dickins 
Acked-by: Michal Hocko 
Tested-by: Helge Deller  # parisc
Signed-off-by: Linus Torvalds 
[Hugh Dickins: Backported to 3.2]
[bwh: Fix more instances of vma->vm_start in sparc64 impl. of
 arch_get_unmapped_area_topdown() and generic impl. of
 hugetlb_get_unmapped_area()]
Signed-off-by: Ben Hutchings

alpha/PCI: Call iomem_is_exclusive() for IORESOURCE_MEM, but not IORESOURCE_IO

2016-08-22T21:37:08+00:00

commit c20e128030caf0537d5e906753eac1c28fefdb75 upstream.

The alpha pci_mmap_resource() is used for both IORESOURCE_MEM and
IORESOURCE_IO resources, but iomem_is_exclusive() is only applicable for
IORESOURCE_MEM.

Call iomem_is_exclusive() only for IORESOURCE_MEM resources, and do it
earlier to match the generic version of pci_mmap_resource().

Fixes: 10a0ef39fbd1 ("PCI/alpha: pci sysfs resources")
Signed-off-by: Bjorn Helgaas 
CC: Ivan Kokshaysky 
Signed-off-by: Ben Hutchings

alpha: Add irongate_io to PCI bus resources

2013-04-25T19:25:33+00:00

commit aa8b4be3ac049c8b1df2a87e4d1d902ccfc1f7a9 upstream.

Fixes a NULL pointer dereference at boot on UP1500.

Reviewed-and-Tested-by: Matt Turner 
Signed-off-by: Jay Estabrook 
Signed-off-by: Matt Turner 
Signed-off-by: Michael Cree 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2011-11-07T03:44:47+00:00

* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
  Revert "tracing: Include module.h in define_trace.h"
  irq: don't put module.h into irq.h for tracking irqgen modules.
  bluetooth: macroize two small inlines to avoid module.h
  ip_vs.h: fix implicit use of module_get/module_put from module.h
  nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
  include: replace linux/module.h with "struct module" wherever possible
  include: convert various register fcns to macros to avoid include chaining
  crypto.h: remove unused crypto_tfm_alg_modname() inline
  uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
  pm_runtime.h: explicitly requires notifier.h
  linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
  miscdevice.h: fix up implicit use of lists and types
  stop_machine.h: fix implicit use of smp.h for smp_processor_id
  of: fix implicit use of errno.h in include/linux/of.h
  of_platform.h: delete needless include 
  acpi: remove module.h include from platform/aclinux.h
  miscdevice.h: delete unnecessary inclusion of module.h
  device_cgroup.h: delete needless include 
  net: sch_generic remove redundant use of 
  net: inet_timewait_sock doesnt need 
  ...

Fix up trivial conflicts (other header files, and  removal of the ab3550 mfd driver) in
 - drivers/media/dvb/frontends/dibx000_common.c
 - drivers/media/video/{mt9m111.c,ov6650.c}
 - drivers/mfd/ab3550-core.c
 - include/linux/dmaengine.h

alpha: wire up sendmmsg syscall

2011-11-01T00:30:51+00:00

Signed-off-by: Michael Cree 
Reviewed-by: Matt Turner 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

alpha: wire up accept4 syscall

2011-11-01T00:30:51+00:00

Somehow wiring up the accept4 syscall on Alpha was missed long ago.
This commit rectifies that oversight.

Signed-off-by: Michael Cree 
Reviewed-by: Matt Turner 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

alpha: Add export.h for THIS_MODULE/EXPORT_SYMBOL

2011-10-31T23:31:03+00:00

These files were getting it via the implicit module.h
presence that was everywhere.

Signed-off-by: Paul Gortmaker

alpha: fix implicit stat.h usage in pci-sysfs.c

2011-10-31T23:31:02+00:00

To avoid this:

arch/alpha/kernel/pci-sysfs.c:164: error: 'S_IRUSR' undeclared (first use in this function)
arch/alpha/kernel/pci-sysfs.c:164: error: 'S_IWUSR' undeclared (first use in this function)
make[2]: *** [arch/alpha/kernel/pci-sysfs.o] Error 1

Signed-off-by: Paul Gortmaker

doc: fix broken references

2011-09-27T16:08:04+00:00

There are numerous broken references to Documentation files (in other
Documentation files, in comments, etc.). These broken references are
caused by typo's in the references, and by renames or removals of the
Documentation files. Some broken references are simply odd.

Fix these broken references, sometimes by dropping the irrelevant text
they were part of.

Signed-off-by: Paul Bolle 
Signed-off-by: Jiri Kosina

All Arch: remove linkage for sys_nfsservctl system call

2011-08-26T22:09:58+00:00

The nfsservctl system call is now gone, so we should remove all
linkage for it.

Signed-off-by: NeilBrown 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Linus Torvalds