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Zhengjun Xing fa2dfd0ec2 xhci: Fix NULL pointer in xhci debugfs
Commit dde634057d ("xhci: Fix use-after-free in xhci debugfs") causes a
null pointer dereference while fixing xhci-debugfs usage of ring pointers
that were freed during hibernate.

The fix passed addresses to ring pointers instead, but forgot to do this
change for the xhci_ring_trb_show function.

The address of the ring pointer passed to xhci-debugfs was of a temporary
ring pointer "new_ring" instead of the actual ring "ring" pointer. The
temporary new_ring pointer will be set to NULL later causing the NULL
pointer dereference.

This issue was seen when reading xhci related files in debugfs:

cat /sys/kernel/debug/usb/xhci/*/devices/*/ep*/trbs

[  184.604861] BUG: unable to handle kernel NULL pointer dereference at (null)
[  184.613776] IP: xhci_ring_trb_show+0x3a/0x890
[  184.618733] PGD 264193067 P4D 264193067 PUD 263238067 PMD 0
[  184.625184] Oops: 0000 [#1] SMP
[  184.726410] RIP: 0010:xhci_ring_trb_show+0x3a/0x890
[  184.731944] RSP: 0018:ffffba8243c0fd90 EFLAGS: 00010246
[  184.737880] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000000295d6
[  184.746020] RDX: 00000000000295d5 RSI: 0000000000000001 RDI: ffff971a6418d400
[  184.754121] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[  184.762222] R10: ffff971a64c98a80 R11: ffff971a62a00e40 R12: ffff971a62a85500
[  184.770325] R13: 0000000000020000 R14: ffff971a6418d400 R15: ffff971a6418d400
[  184.778448] FS:  00007fe725a79700(0000) GS:ffff971a6ec00000(0000) knlGS:0000000000000000
[  184.787644] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  184.794168] CR2: 0000000000000000 CR3: 000000025f365005 CR4: 00000000003606f0
[  184.802318] Call Trace:
[  184.805094]  ? seq_read+0x281/0x3b0
[  184.809068]  seq_read+0xeb/0x3b0
[  184.812735]  full_proxy_read+0x4d/0x70
[  184.817007]  __vfs_read+0x23/0x120
[  184.820870]  vfs_read+0x91/0x130
[  184.824538]  SyS_read+0x42/0x90
[  184.828106]  entry_SYSCALL_64_fastpath+0x1a/0x7d

Fixes: dde634057d ("xhci: Fix use-after-free in xhci debugfs")
Cc: <stable@vger.kernel.org> # v4.15
Signed-off-by: Zhengjun Xing <zhengjun.xing@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-15 18:36:19 +01:00
Documentation KVM changes for 4.16 2018-02-10 13:16:35 -08:00
LICENSES LICENSES: Add MPL-1.1 license 2018-01-06 10:59:44 -07:00
arch unify {de,}mangle_poll(), get rid of kernel-side POLL... 2018-02-11 14:37:22 -08:00
block vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
drivers xhci: Fix NULL pointer in xhci debugfs 2018-02-15 18:36:19 +01:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
include unify {de,}mangle_poll(), get rid of kernel-side POLL... 2018-02-11 14:37:22 -08:00
init membarrier: Provide core serializing command, *_SYNC_CORE 2018-02-05 21:35:03 +01:00
ipc vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
kernel vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
lib Kbuild updates for v4.16 (2nd) 2018-02-09 19:32:41 -08:00
mm vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
net vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
samples sample/bpf: fix erspan metadata 2018-02-06 11:32:49 -05:00
scripts Kbuild updates for v4.16 (2nd) 2018-02-09 19:32:41 -08:00
security vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
sound vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-02-09 15:34:18 -08:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore scripts/package: snap-pkg target 2017-12-13 00:00:18 +09:00
.mailmap mailmap: update Mark Yao's email address 2018-01-04 16:45:09 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS KVM changes for 4.16 2018-02-10 13:16:35 -08:00
Makefile Linux 4.16-rc1 2018-02-11 15:04:29 -08:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.