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Gaosheng Cui f70960981f lib/fonts: fix undefined behavior in bit shift for get_default_font
[ Upstream commit 6fe888c4d2 ]

Shifting signed 32-bit value by 31 bits is undefined, so changing
significant bit to unsigned.  The UBSAN warning calltrace like below:

UBSAN: shift-out-of-bounds in lib/fonts/fonts.c:139:20
left shift of 1 by 31 places cannot be represented in type 'int'
 <TASK>
 dump_stack_lvl+0x7d/0xa5
 dump_stack+0x15/0x1b
 ubsan_epilogue+0xe/0x4e
 __ubsan_handle_shift_out_of_bounds+0x1e7/0x20c
 get_default_font+0x1c7/0x1f0
 fbcon_startup+0x347/0x3a0
 do_take_over_console+0xce/0x270
 do_fbcon_takeover+0xa1/0x170
 do_fb_registered+0x2a8/0x340
 fbcon_fb_registered+0x47/0xe0
 register_framebuffer+0x294/0x4a0
 __drm_fb_helper_initial_config_and_unlock+0x43c/0x880 [drm_kms_helper]
 drm_fb_helper_initial_config+0x52/0x80 [drm_kms_helper]
 drm_fbdev_client_hotplug+0x156/0x1b0 [drm_kms_helper]
 drm_fbdev_generic_setup+0xfc/0x290 [drm_kms_helper]
 bochs_pci_probe+0x6ca/0x772 [bochs]
 local_pci_probe+0x4d/0xb0
 pci_device_probe+0x119/0x320
 really_probe+0x181/0x550
 __driver_probe_device+0xc6/0x220
 driver_probe_device+0x32/0x100
 __driver_attach+0x195/0x200
 bus_for_each_dev+0xbb/0x120
 driver_attach+0x27/0x30
 bus_add_driver+0x22e/0x2f0
 driver_register+0xa9/0x190
 __pci_register_driver+0x90/0xa0
 bochs_pci_driver_init+0x52/0x1000 [bochs]
 do_one_initcall+0x76/0x430
 do_init_module+0x61/0x28a
 load_module+0x1f82/0x2e50
 __do_sys_finit_module+0xf8/0x190
 __x64_sys_finit_module+0x23/0x30
 do_syscall_64+0x58/0x80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
 </TASK>

Link: https://lkml.kernel.org/r/20221031113829.4183153-1-cuigaosheng1@huawei.com
Fixes: c81f717cb9 ("fbcon: Fix typo and bogus logic in get_default_font")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-19 17:57:13 +08:00
arch x86/sgx: Reduce delay and interference of enclave release 2023-04-19 17:57:13 +08:00
block block: move CONFIG_BLOCK guard to top Makefile 2023-04-19 17:57:04 +08:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2023-04-19 17:50:34 +08:00
crypto crypto: akcipher - default implementation for setting a private key 2023-04-19 17:55:27 +08:00
Documentation docs: update mediator contact information in CoC doc 2023-04-19 17:56:27 +08:00
drivers platform/x86: huawei-wmi: fix return value calculation 2023-04-19 17:57:13 +08:00
fs fs: don't audit the capability check in simple_xattr_list() 2023-04-19 17:57:13 +08:00
include timerqueue: Use rb_entry_safe() in timerqueue_getnext() 2023-04-19 17:57:13 +08:00
init init/Kconfig: fix CC_HAS_ASM_GOTO_TIED_OUTPUT test with dash 2023-04-19 17:56:40 +08:00
io_uring io_uring: Fix a null-ptr-deref in io_tctx_exit_cb() 2023-04-19 17:57:04 +08:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2023-04-19 17:56:54 +08:00
kernel perf: Fix possible memleak in pmu_dev_alloc() 2023-04-19 17:57:13 +08:00
lib lib/fonts: fix undefined behavior in bit shift for get_default_font 2023-04-19 17:57:13 +08:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm mm/gup: fix gup_pud_range() for dax 2023-04-19 17:56:58 +08:00
net Bluetooth: L2CAP: Fix u8 overflow 2023-04-19 17:57:06 +08:00
samples samples/landlock: Format with clang-format 2023-04-19 17:50:01 +08:00
scripts scripts/faddr2line: Fix regression in name resolution on ppc64le 2023-04-19 17:56:46 +08:00
security capabilities: fix potential memleak on error path from vfs_getxattr_alloc() 2023-04-19 17:56:03 +08:00
sound ASoC: ops: Correct bounds check for second channel on SX controls 2023-04-19 17:57:05 +08:00
tools proc: fixup uptime selftest 2023-04-19 17:57:13 +08:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2023-04-19 17:44:58 +08:00
virt kvm: Add support for arch compat vm ioctls 2023-04-19 17:55:40 +08:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.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: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
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 io_uring: move to separate directory 2023-04-19 17:57:04 +08:00
Makefile Linux 5.15.85 2023-04-19 17:57:07 +08:00
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.