Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1648781

[PATCH 4.4 103/103] drivers: char: mem: Check for address space wraparound with mmap()

From Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newsgroups linux.kernel
Subject [PATCH 4.4 103/103] drivers: char: mem: Check for address space wraparound with mmap()
Date 2017-05-23 23:30 +0200
Message-ID <tKpxp-AI-57@gated-at.bofh.it> (permalink)
References <tKoKZ-8pv-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Julius Werner <jwerner@chromium.org>

commit b299cde245b0b76c977f4291162cf668e087b408 upstream.

/dev/mem currently allows mmap() mappings that wrap around the end of
the physical address space, which should probably be illegal. It
circumvents the existing STRICT_DEVMEM permission check because the loop
immediately terminates (as the start address is already higher than the
end address). On the x86_64 architecture it will then cause a panic
(from the BUG(start >= end) in arch/x86/mm/pat.c:reserve_memtype()).

This patch adds an explicit check to make sure offset + size will not
wrap around in the physical address type.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/char/mem.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -343,6 +343,11 @@ static const struct vm_operations_struct
 static int mmap_mem(struct file *file, struct vm_area_struct *vma)
 {
 	size_t size = vma->vm_end - vma->vm_start;
+	phys_addr_t offset = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT;
+
+	/* It's illegal to wrap around the end of the physical address space. */
+	if (offset + (phys_addr_t)size < offset)
+		return -EINVAL;
 
 	if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size))
 		return -EINVAL;

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 4.4 000/103] 4.4.70-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:00 +0200
  [PATCH 4.4 099/103] PCI: Fix pci_mmap_fits() for HAVE_PCI_RESOURCE_TO_USER platforms Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:00 +0200
  [PATCH 4.4 098/103] tracing/kprobes: Enforce kprobes teardown after testing Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:00 +0200
  [PATCH 4.4 097/103] osf_wait4(): fix infoleak Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:00 +0200
  [PATCH 4.4 095/103] uwb: fix device quirk on big-endian hosts Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:00 +0200
  [PATCH 4.4 012/103] dm bufio: avoid a possible ABBA deadlock Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:00 +0200
  [PATCH 4.4 037/103] proc: Fix unbalanced hard link numbers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:00 +0200
  [PATCH 4.4 029/103] drm/amdgpu: Avoid overflows/divide-by-zero in latency_watermark calculations. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:00 +0200
  [PATCH 4.4 034/103] drm/nouveau/tmr: avoid processing completed alarms when adding a new one Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:00 +0200
  [PATCH 4.4 030/103] drm/amdgpu: Make display watermark calculations more accurate Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:00 +0200
  [PATCH 4.4 078/103] [media] cx231xx-cards: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:00 +0200
  [PATCH 4.4 014/103] dm cache metadata: fail operations if fail_io mode has been established Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:00 +0200
  [PATCH 4.4 077/103] [media] cx231xx-audio: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
  [PATCH 4.4 080/103] powerpc/pseries: Fix of_node_put() underflow during DLPAR remove Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
  [PATCH 4.4 073/103] [media] dib0700: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
  [PATCH 4.4 082/103] ARM: dts: at91: sama5d3_xplained: fix ADC vref Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
  [PATCH 4.4 081/103] powerpc/64e: Fix hang when debugging programs with relocated kernel Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
  [PATCH 4.4 079/103] powerpc/book3s/mce: Move add_taint() later in virtual mode Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
  [PATCH 4.4 102/103] nfsd: encoders mustnt use unitialized values in error cases Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:30 +0200
  [PATCH 4.4 103/103] drivers: char: mem: Check for address space wraparound with mmap() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:30 +0200
  [PATCH 4.4 101/103] drm/edid: Add 10 bpc quirk for LGD 764 panel in HP zBook 17 G2 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:30 +0200
  Re: [PATCH 4.4 000/103] 4.4.70-stable review Guenter Roeck <linux@roeck-us.net> - 2017-05-24 06:10 +0200
    Re: [PATCH 4.4 000/103] 4.4.70-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-24 09:00 +0200
      Re: [PATCH 4.4 000/103] 4.4.70-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-24 09:00 +0200
  Re: [PATCH 4.4 000/103] 4.4.70-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-24 09:10 +0200
    Re: [PATCH 4.4 000/103] 4.4.70-stable review Thomas Voegtle <tv@lio96.de> - 2017-05-24 11:40 +0200
      Re: [PATCH 4.4 000/103] 4.4.70-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-24 13:40 +0200
        Re: [PATCH 4.4 000/103] 4.4.70-stable review Thomas Voegtle <tv@lio96.de> - 2017-05-24 14:10 +0200
          Re: [PATCH 4.4 000/103] 4.4.70-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-24 15:00 +0200
    Re: [PATCH 4.4 000/103] 4.4.70-stable review Guenter Roeck <linux@roeck-us.net> - 2017-05-24 14:50 +0200
      Re: [PATCH 4.4 000/103] 4.4.70-stable review Mark Brown <broonie@kernel.org> - 2017-05-24 15:10 +0200
        Re: [PATCH 4.4 000/103] 4.4.70-stable review Guenter Roeck <linux@roeck-us.net> - 2017-05-24 15:20 +0200
          Re: [PATCH 4.4 000/103] 4.4.70-stable review Mark Brown <broonie@kernel.org> - 2017-05-24 17:10 +0200
        Re: [PATCH 4.4 000/103] 4.4.70-stable review Guenter Roeck <linux@roeck-us.net> - 2017-05-24 15:40 +0200
  Re: [PATCH 4.4 000/103] 4.4.70-stable review Guenter Roeck <linux@roeck-us.net> - 2017-05-24 22:30 +0200

csiph-web