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Linux kernel source tree
Check for a NULL page->mapping before dereferencing the mapping in
page_is_secretmem(), as the page's mapping can be nullified while gup()
is running, e.g. by reclaim or truncation.
BUG: kernel NULL pointer dereference, address: 0000000000000068
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 6 PID: 4173897 Comm: CPU 3/KVM Tainted: G W
RIP: 0010:internal_get_user_pages_fast+0x621/0x9d0
Code: <48> 81 7a 68 80 08 04 bc 0f 85 21 ff ff 8 89 c7 be
RSP: 0018:ffffaa90087679b0 EFLAGS: 00010046
RAX: ffffe3f37905b900 RBX: 00007f2dd561e000 RCX: ffffe3f37905b934
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffe3f37905b900
...
CR2: 0000000000000068 CR3: 00000004c5898003 CR4: 00000000001726e0
Call Trace:
get_user_pages_fast_only+0x13/0x20
hva_to_pfn+0xa9/0x3e0
try_async_pf+0xa1/0x270
direct_page_fault+0x113/0xad0
kvm_mmu_page_fault+0x69/0x680
vmx_handle_exit+0xe1/0x5d0
kvm_arch_vcpu_ioctl_run+0xd81/0x1c70
kvm_vcpu_ioctl+0x267/0x670
__x64_sys_ioctl+0x83/0xa0
do_syscall_64+0x56/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Link: https://lkml.kernel.org/r/20211007231502.3552715-1-seanjc@google.com
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.