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Lu Baolu 6097df457a iommu/vt-d: Fix kernel NULL pointer dereference in find_domain()
If calling find_domain() for a device which hasn't been probed by the
iommu core, below kernel NULL pointer dereference issue happens.

[  362.736947] BUG: kernel NULL pointer dereference, address: 0000000000000038
[  362.743953] #PF: supervisor read access in kernel mode
[  362.749115] #PF: error_code(0x0000) - not-present page
[  362.754278] PGD 0 P4D 0
[  362.756843] Oops: 0000 [#1] SMP NOPTI
[  362.760528] CPU: 0 PID: 844 Comm: cat Not tainted 5.9.0-rc4-intel-next+ #1
[  362.767428] Hardware name: Intel Corporation Ice Lake Client Platform/IceLake
               U DDR4 SODIMM PD RVP TLC, BIOS ICLSFWR1.R00.3384.A02.1909200816
               09/20/2019
[  362.781109] RIP: 0010:find_domain+0xd/0x40
[  362.785234] Code: 48 81 fb 60 28 d9 b2 75 de 5b 41 5c 41 5d 5d c3 0f 1f 00 66
                     2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 8b 87 e0 02 00
                     00 55 <48> 8b 40 38 48 89 e5 48 83 f8 fe 0f 94 c1 48 85 ff
                     0f 94 c2 08 d1
[  362.804041] RSP: 0018:ffffb09cc1f0bd38 EFLAGS: 00010046
[  362.809292] RAX: 0000000000000000 RBX: ffff905b98e4fac8 RCX: 0000000000000000
[  362.816452] RDX: 0000000000000001 RSI: ffff905b98e4fac8 RDI: ffff905b9ccd40d0
[  362.823617] RBP: ffffb09cc1f0bda0 R08: ffffb09cc1f0bd48 R09: 000000000000000f
[  362.830778] R10: ffffffffb266c080 R11: ffff905b9042602d R12: ffff905b98e4fac8
[  362.837944] R13: ffffb09cc1f0bd48 R14: ffff905b9ccd40d0 R15: ffff905b98e4fac8
[  362.845108] FS:  00007f8485460740(0000) GS:ffff905b9fc00000(0000)
               knlGS:0000000000000000
[  362.853227] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  362.858996] CR2: 0000000000000038 CR3: 00000004627a6003 CR4: 0000000000770ef0
[  362.866161] PKRU: fffffffc
[  362.868890] Call Trace:
[  362.871363]  ? show_device_domain_translation+0x32/0x100
[  362.876700]  ? bind_store+0x110/0x110
[  362.880387]  ? klist_next+0x91/0x120
[  362.883987]  ? domain_translation_struct_show+0x50/0x50
[  362.889237]  bus_for_each_dev+0x79/0xc0
[  362.893121]  domain_translation_struct_show+0x36/0x50
[  362.898204]  seq_read+0x135/0x410
[  362.901545]  ? handle_mm_fault+0xeb8/0x1750
[  362.905755]  full_proxy_read+0x5c/0x90
[  362.909526]  vfs_read+0xa6/0x190
[  362.912782]  ksys_read+0x61/0xe0
[  362.916037]  __x64_sys_read+0x1a/0x20
[  362.919725]  do_syscall_64+0x37/0x80
[  362.923329]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  362.928405] RIP: 0033:0x7f84855c5e95

Filter out those devices to avoid such error.

Fixes: e2726daea5 ("iommu/vt-d: debugfs: Add support to show page table internals")
Reported-and-tested-by: Xu Pengfei <pengfei.xu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Cc: stable@vger.kernel.org#v5.6+
Link: https://lore.kernel.org/r/20201028070725.24979-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-11-03 14:30:10 +01:00
arch Three fixes all related to #DB: 2020-11-01 11:21:26 -08:00
block blk-mq: mark flush request as IDLE in flush_end_io() 2020-10-30 08:33:49 -06:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto drivers-5.10-2020-10-12 2020-10-13 13:04:41 -07:00
Documentation Char/Misc fixes/removals for 5.10-rc2 2020-11-01 10:05:16 -08:00
drivers iommu/vt-d: Fix kernel NULL pointer dereference in find_domain() 2020-11-03 14:30:10 +01:00
fs Driver core / Documentation fixes for 5.10-rc2 2020-11-01 09:59:13 -08:00
include A few fixes for timers/timekeeping: 2020-11-01 11:13:45 -08:00
init linux-kselftest-kunit-5.10-rc1 2020-10-18 14:45:59 -07:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel A few fixes for timers/timekeeping: 2020-11-01 11:13:45 -08:00
lib Driver core / Documentation fixes for 5.10-rc2 2020-11-01 09:59:13 -08:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm/process_vm_access: Add missing #include <linux/compat.h> 2020-10-27 12:41:29 -07:00
net flexible-array member conversion patches for 5.10-rc2 2020-10-31 14:31:28 -07:00
samples misc: mic: remove the MIC drivers 2020-10-28 19:12:03 +01:00
scripts scripts: get_abi.pl: assume ReST format by default 2020-10-30 13:16:03 +01:00
security ima: Replace zero-length array with flexible-array member 2020-10-29 17:22:59 -05:00
sound ARM: SoC platform updates 2020-10-24 10:33:08 -07:00
tools ARM: 2020-11-01 09:43:32 -08:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt kvm: x86/mmu: Support dirty logging for the TDP MMU 2020-10-23 03:42:13 -04:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap MAINTAINERS: jarkko.sakkinen@linux.intel.com -> jarkko@kernel.org 2020-10-16 11:11:19 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Sangbeom Kim to credits 2020-10-26 10:11:18 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Char/Misc fixes/removals for 5.10-rc2 2020-11-01 10:05:16 -08:00
Makefile Linux 5.10-rc2 2020-11-01 14:43:51 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

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.