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A mirror of the official Linux kernel repository just in case
51a6fa0732
When running with return thunks enabled under 32-bit EFI, the system
crashes with:
kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
BUG: unable to handle page fault for address: 000000005bc02900
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0011) - permissions violation
PGD 18f7063 P4D 18f7063 PUD 18ff063 PMD 190e063 PTE 800000005bc02063
Oops: 0011 [#1] PREEMPT SMP PTI
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.19.0-rc6+ #166
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:0x5bc02900
Code: Unable to access opcode bytes at RIP 0x5bc028d6.
RSP: 0018:ffffffffb3203e10 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000048
RDX: 000000000190dfac RSI: 0000000000001710 RDI: 000000007eae823b
RBP: ffffffffb3203e70 R08: 0000000001970000 R09: ffffffffb3203e28
R10: 747563657865206c R11: 6c6977203a696665 R12: 0000000000001710
R13: 0000000000000030 R14: 0000000001970000 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8e013ca00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0018 ES: 0018 CR0: 0000000080050033
CR2: 000000005bc02900 CR3: 0000000001930000 CR4: 00000000000006f0
Call Trace:
? efi_set_virtual_address_map+0x9c/0x175
efi_enter_virtual_mode+0x4a6/0x53e
start_kernel+0x67c/0x71e
x86_64_start_reservations+0x24/0x2a
x86_64_start_kernel+0xe9/0xf4
secondary_startup_64_no_verify+0xe5/0xeb
That's because it cannot jump to the return thunk from the 32-bit code.
Using a naked RET and marking it as safe allows the system to proceed
booting.
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.