commit 0711f0d7050b9e07c44bc159bbc64ac0a1022c7f upstream.
During boot, kernel_init_freeable() initializes `cad_pid` to the init
task's struct pid. Later on, we may change `cad_pid` via a sysctl, and
when this happens proc_do_cad_pid() will increment the refcount on the
new pid via get_pid(), and will decrement the refcount on the old pid
via put_pid(). As we never called get_pid() when we initialized
`cad_pid`, we decrement a reference we never incremented, can therefore
free the init task's struct pid early. As there can be dangling
references to the struct pid, we can later encounter a use-after-free
(e.g. when delivering signals).
This was spotted when fuzzing v5.13-rc3 with Syzkaller, but seems to
have been around since the conversion of `cad_pid` to struct pid in
commit 9ec52099e4 ("[PATCH] replace cad_pid by a struct pid") from the
pre-KASAN stone age of v2.6.19.
Fix this by getting a reference to the init task's struct pid when we
assign it to `cad_pid`.
Full KASAN splat below.
==================================================================
BUG: KASAN: use-after-free in ns_of_pid include/linux/pid.h:153 [inline]
BUG: KASAN: use-after-free in task_active_pid_ns+0xc0/0xc8 kernel/pid.c:509
Read of size 4 at addr ffff23794dda0004 by task syz-executor.0/273
CPU: 1 PID: 273 Comm: syz-executor.0 Not tainted 5.12.0-00001-g9aef892b2d15 #1
Hardware name: linux,dummy-virt (DT)
Call trace:
ns_of_pid include/linux/pid.h:153 [inline]
task_active_pid_ns+0xc0/0xc8 kernel/pid.c:509
do_notify_parent+0x308/0xe60 kernel/signal.c:1950
exit_notify kernel/exit.c:682 [inline]
do_exit+0x2334/0x2bd0 kernel/exit.c:845
do_group_exit+0x108/0x2c8 kernel/exit.c:922
get_signal+0x4e4/0x2a88 kernel/signal.c:2781
do_signal arch/arm64/kernel/signal.c:882 [inline]
do_notify_resume+0x300/0x970 arch/arm64/kernel/signal.c:936
work_pending+0xc/0x2dc
Allocated by task 0:
slab_post_alloc_hook+0x50/0x5c0 mm/slab.h:516
slab_alloc_node mm/slub.c:2907 [inline]
slab_alloc mm/slub.c:2915 [inline]
kmem_cache_alloc+0x1f4/0x4c0 mm/slub.c:2920
alloc_pid+0xdc/0xc00 kernel/pid.c:180
copy_process+0x2794/0x5e18 kernel/fork.c:2129
kernel_clone+0x194/0x13c8 kernel/fork.c:2500
kernel_thread+0xd4/0x110 kernel/fork.c:2552
rest_init+0x44/0x4a0 init/main.c:687
arch_call_rest_init+0x1c/0x28
start_kernel+0x520/0x554 init/main.c:1064
0x0
Freed by task 270:
slab_free_hook mm/slub.c:1562 [inline]
slab_free_freelist_hook+0x98/0x260 mm/slub.c:1600
slab_free mm/slub.c:3161 [inline]
kmem_cache_free+0x224/0x8e0 mm/slub.c:3177
put_pid.part.4+0xe0/0x1a8 kernel/pid.c:114
put_pid+0x30/0x48 kernel/pid.c:109
proc_do_cad_pid+0x190/0x1b0 kernel/sysctl.c:1401
proc_sys_call_handler+0x338/0x4b0 fs/proc/proc_sysctl.c:591
proc_sys_write+0x34/0x48 fs/proc/proc_sysctl.c:617
call_write_iter include/linux/fs.h:1977 [inline]
new_sync_write+0x3ac/0x510 fs/read_write.c:518
vfs_write fs/read_write.c:605 [inline]
vfs_write+0x9c4/0x1018 fs/read_write.c:585
ksys_write+0x124/0x240 fs/read_write.c:658
__do_sys_write fs/read_write.c:670 [inline]
__se_sys_write fs/read_write.c:667 [inline]
__arm64_sys_write+0x78/0xb0 fs/read_write.c:667
__invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:49 [inline]
el0_svc_common.constprop.1+0x16c/0x388 arch/arm64/kernel/syscall.c:129
do_el0_svc+0xf8/0x150 arch/arm64/kernel/syscall.c:168
el0_svc+0x28/0x38 arch/arm64/kernel/entry-common.c:416
el0_sync_handler+0x134/0x180 arch/arm64/kernel/entry-common.c:432
el0_sync+0x154/0x180 arch/arm64/kernel/entry.S:701
The buggy address belongs to the object at ffff23794dda0000
which belongs to the cache pid of size 224
The buggy address is located 4 bytes inside of
224-byte region [ffff23794dda0000, ffff23794dda00e0)
The buggy address belongs to the page:
page:(____ptrval____) refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4dda0
head:(____ptrval____) order:1 compound_mapcount:0
flags: 0x3fffc0000010200(slab|head)
raw: 03fffc0000010200 dead000000000100 dead000000000122 ffff23794d40d080
raw: 0000000000000000 0000000000190019 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff23794dd9ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff23794dd9ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff23794dda0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff23794dda0080: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
ffff23794dda0100: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
==================================================================
Link: https://lkml.kernel.org/r/20210524172230.38715-1-mark.rutland@arm.com
Fixes: 9ec52099e4 ("[PATCH] replace cad_pid by a struct pid")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Christian Brauner <christian@brauner.io>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d54ce6158e354f5358a547b96299ecd7f3725393 upstream.
Currently breakpoints in kernel .init.text section are not handled
correctly while allowing to remove them even after corresponding pages
have been freed.
Fix it via killing .init.text section breakpoints just prior to initmem
pages being freed.
Doug: "HW breakpoints aren't handled by this patch but it's probably
not such a big deal".
Link: https://lkml.kernel.org/r/20210224081652.587785-1-sumit.garg@linaro.org
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Suggested-by: Doug Anderson <dianders@chromium.org>
Acked-by: Doug Anderson <dianders@chromium.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1b04fa9900263b4e217ca2509fd778b32c2b4eb2 ]
PowerPC testing encountered boot failures due to RCU Tasks not being
fully initialized until core_initcall() time. This commit therefore
initializes RCU Tasks (along with Rude RCU and RCU Tasks Trace) just
before early_initcall() time, thus allowing waiting on RCU Tasks grace
periods from early_initcall() handlers.
Link: https://lore.kernel.org/rcu/87eekfh80a.fsf@dja-thinkpad.axtens.net/
Fixes: 36dadef23f ("kprobes: Init kprobes in early_initcall")
Tested-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Load the size and the checksum fields in the footer as le32
instead of u32. This will allow us to apply bootconfig to the
cross build initrd without caring the endianness.
Link: https://lkml.kernel.org/r/160583934457.547349.10504070298990791074.stgit@devnote2
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since Grub may align the size of initrd to 4 if user pass
initrd from cpio, we have to check the preceding 3 bytes as well.
Link: https://lkml.kernel.org/r/160520205132.303174.4876760192433315429.stgit@devnote2
Cc: stable@vger.kernel.org
Fixes: 85c46b78da ("bootconfig: Add bootconfig magic word for indicating bootconfig explicitly")
Reported-by: Chen Yu <yu.chen.surf@gmail.com>
Tested-by: Chen Yu <yu.chen.surf@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This Kunit update for Linux 5.10-rc1 consists of:
- add Kunit to kernel_init() and remove KUnit from init calls entirely.
This addresses the concern Kunit would not work correctly during
late init phase.
- add a linker section where KUnit can put references to its test suites.
This patch is the first step in transitioning to dispatching all KUnit
tests from a centralized executor rather than having each as its own
separate late_initcall.
- add a centralized executor to dispatch tests rather than relying on
late_initcall to schedule each test suite separately. Centralized
execution is for built-in tests only; modules will execute tests when
loaded.
- convert bitfield test to use KUnit framework
- Documentation updates for naming guidelines and how kunit_test_suite()
works.
- add test plan to KUnit TAP format
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Merge tag 'linux-kselftest-kunit-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull more Kunit updates from Shuah Khan:
- add Kunit to kernel_init() and remove KUnit from init calls entirely.
This addresses the concern that Kunit would not work correctly during
late init phase.
- add a linker section where KUnit can put references to its test
suites.
This is the first step in transitioning to dispatching all KUnit
tests from a centralized executor rather than having each as its own
separate late_initcall.
- add a centralized executor to dispatch tests rather than relying on
late_initcall to schedule each test suite separately. Centralized
execution is for built-in tests only; modules will execute tests when
loaded.
- convert bitfield test to use KUnit framework
- Documentation updates for naming guidelines and how
kunit_test_suite() works.
- add test plan to KUnit TAP format
* tag 'linux-kselftest-kunit-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
lib: kunit: Fix compilation test when using TEST_BIT_FIELD_COMPILE
lib: kunit: add bitfield test conversion to KUnit
Documentation: kunit: add a brief blurb about kunit_test_suite
kunit: test: add test plan to KUnit TAP format
init: main: add KUnit to kernel init
kunit: test: create a single centralized executor for all tests
vmlinux.lds.h: add linker section for KUnit test suites
Documentation: kunit: Add naming guidelines
Pull trivial updates from Jiri Kosina:
"The latest advances in computer science from the trivial queue"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
xtensa: fix Kconfig typo
spelling.txt: Remove some duplicate entries
mtd: rawnand: oxnas: cleanup/simplify code
selftests: vm: add fragment CONFIG_GUP_BENCHMARK
perf: Fix opt help text for --no-bpf-event
HID: logitech-dj: Fix spelling in comment
bootconfig: Fix kernel message mentioning CONFIG_BOOT_CONFIG
MAINTAINERS: rectify MMP SUPPORT after moving cputype.h
scif: Fix spelling of EACCES
printk: fix global comment
lib/bitmap.c: fix spello
fs: Fix missing 'bit' in comment
Although we have not seen any actual examples where KUnit doesn't work
because it runs in the late init phase of the kernel, it has been a
concern for some time that this could potentially be an issue in the
future. So, remove KUnit from init calls entirely, instead call directly
from kernel_init() so that KUnit runs after late init.
Co-developed-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
This eliminates the following sparse warning:
init/main.c:306:6: warning: symbol 'xbc_namebuf' was not declared.
Should it be static?
Link: https://lkml.kernel.org/r/20200915070324.2239473-1-yanaijie@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since kprobe_event= cmdline option allows user to put kprobes on the
functions in initmem, kprobe has to make such probes gone after boot.
Currently the probes on the init functions in modules will be handled
by module callback, but the kernel init text isn't handled.
Without this, kprobes may access non-exist text area to disable or
remove it.
Link: https://lkml.kernel.org/r/159972810544.428528.1839307531600646955.stgit@devnote2
Fixes: 970988e19e ("tracing/kprobe: Add kprobe_event= boot parameter")
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
- The biggest news in that the tracing ring buffer can now time events that
interrupted other ring buffer events. Before this change, if an interrupt
came in while recording another event, and that interrupt also had an
event, those events would all have the same time stamp as the event it
interrupted. Now, with the new design, those events will have a unique time
stamp and rightfully display the time for those events that were recorded
while interrupting another event.
- Bootconfig how has an "override" operator that lets the users have a
default config, but then add options to override the default.
- A fix was made to properly filter function graph tracing to the ftrace
PIDs. This came in at the end of the -rc cycle, and needs to be backported.
- Several clean ups, performance updates, and minor fixes as well.
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Merge tag 'trace-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
- The biggest news in that the tracing ring buffer can now time events
that interrupted other ring buffer events.
Before this change, if an interrupt came in while recording another
event, and that interrupt also had an event, those events would all
have the same time stamp as the event it interrupted.
Now, with the new design, those events will have a unique time stamp
and rightfully display the time for those events that were recorded
while interrupting another event.
- Bootconfig how has an "override" operator that lets the users have a
default config, but then add options to override the default.
- A fix was made to properly filter function graph tracing to the
ftrace PIDs. This came in at the end of the -rc cycle, and needs to
be backported.
- Several clean ups, performance updates, and minor fixes as well.
* tag 'trace-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (39 commits)
tracing: Add trace_array_init_printk() to initialize instance trace_printk() buffers
kprobes: Fix compiler warning for !CONFIG_KPROBES_ON_FTRACE
tracing: Use trace_sched_process_free() instead of exit() for pid tracing
bootconfig: Fix to find the initargs correctly
Documentation: bootconfig: Add bootconfig override operator
tools/bootconfig: Add testcases for value override operator
lib/bootconfig: Add override operator support
kprobes: Remove show_registers() function prototype
tracing/uprobe: Remove dead code in trace_uprobe_register()
kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler
ftrace: Fix ftrace_trace_task return value
tracepoint: Use __used attribute definitions from compiler_attributes.h
tracepoint: Mark __tracepoint_string's __used
trace : Have tracing buffer info use kvzalloc instead of kzalloc
tracing: Remove outdated comment in stack handling
ftrace: Do not let direct or IPMODIFY ftrace_ops be added to module and set trampolines
ftrace: Setup correct FTRACE_FL_REGS flags for module
tracing/hwlat: Honor the tracing_cpumask
tracing/hwlat: Drop the duplicate assignment in start_kthread()
tracing: Save one trace_event->type by using __TRACE_LAST_TYPE
...
Merge misc updates from Andrew Morton:
- a few MM hotfixes
- kthread, tools, scripts, ntfs and ocfs2
- some of MM
Subsystems affected by this patch series: kthread, tools, scripts, ntfs,
ocfs2 and mm (hofixes, pagealloc, slab-generic, slab, slub, kcsan,
debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, mincore,
sparsemem, vmalloc, kasan, pagealloc, hugetlb and vmscan).
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
mm: vmscan: consistent update to pgrefill
mm/vmscan.c: fix typo
khugepaged: khugepaged_test_exit() check mmget_still_valid()
khugepaged: retract_page_tables() remember to test exit
khugepaged: collapse_pte_mapped_thp() protect the pmd lock
khugepaged: collapse_pte_mapped_thp() flush the right range
mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible
mm: thp: replace HTTP links with HTTPS ones
mm/page_alloc: fix memalloc_nocma_{save/restore} APIs
mm/page_alloc.c: skip setting nodemask when we are in interrupt
mm/page_alloc: fallbacks at most has 3 elements
mm/page_alloc: silence a KASAN false positive
mm/page_alloc.c: remove unnecessary end_bitidx for [set|get]_pfnblock_flags_mask()
mm/page_alloc.c: simplify pageblock bitmap access
mm/page_alloc.c: extract the common part in pfn_to_bitidx()
mm/page_alloc.c: replace the definition of NR_MIGRATETYPE_BITS with PB_migratetype_bits
mm/shuffle: remove dynamic reconfiguration
mm/memory_hotplug: document why shuffle_zone() is relevant
mm/page_alloc: remove nr_free_pagecache_pages()
mm: remove vm_total_pages
...
This patch prepares Software Tag-Based KASAN for stack tagging support.
With stack tagging enabled, KASAN tags stack variable in each function in
its prologue. In start_kernel() stack variables get tagged before KASAN
is enabled via setup_arch()->kasan_init(). As the result the tags for
start_kernel()'s stack variables end up in the temporary shadow memory.
Later when KASAN gets enabled, switched to normal shadow, and starts
checking tags, this leads to false-positive reports, as proper tags are
missing in normal shadow.
Disable KASAN instrumentation for start_kernel(). Also disable it for
arm64's setup_arch() as a precaution (it doesn't have any stack variables
right now).
[andreyknvl@google.com: reorder attributes for start_kernel()]
Link: http://lkml.kernel.org/r/26fb6165a17abcf61222eda5184c030fb6b133d1.1596544734.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Elena Petrova <lenaptr@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Walter Wu <walter-zh.wu@mediatek.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Link: http://lkml.kernel.org/r/55d432671a92e931ab8234b03dc36b14d4c21bfb.1596199677.git.andreyknvl@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull init and set_fs() cleanups from Al Viro:
"Christoph's 'getting rid of ksys_...() uses under KERNEL_DS' series"
* 'hch.init_path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (50 commits)
init: add an init_dup helper
init: add an init_utimes helper
init: add an init_stat helper
init: add an init_mknod helper
init: add an init_mkdir helper
init: add an init_symlink helper
init: add an init_link helper
init: add an init_eaccess helper
init: add an init_chmod helper
init: add an init_chown helper
init: add an init_chroot helper
init: add an init_chdir helper
init: add an init_rmdir helper
init: add an init_unlink helper
init: add an init_umount helper
init: add an init_mount helper
init: mark create_dev as __init
init: mark console_on_rootfs as __init
init: initialize ramdisk_execute_command at compile time
devtmpfs: refactor devtmpfsd()
...
Add a simple helper to grab a reference to a file and install it at
the next available fd, and switch the early init code over to it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull execve updates from Eric Biederman:
"During the development of v5.7 I ran into bugs and quality of
implementation issues related to exec that could not be easily fixed
because of the way exec is implemented. So I have been diggin into
exec and cleaning up what I can.
This cycle I have been looking at different ideas and different
implementations to see what is possible to improve exec, and cleaning
the way exec interfaces with in kernel users. Only cleaning up the
interfaces of exec with rest of the kernel has managed to stabalize
and make it through review in time for v5.9-rc1 resulting in 2 sets of
changes this cycle.
- Implement kernel_execve
- Make the user mode driver code a better citizen
With kernel_execve the code size got a little larger as the copying of
parameters from userspace and copying of parameters from userspace is
now separate. The good news is kernel threads no longer need to play
games with set_fs to use exec. Which when combined with the rest of
Christophs set_fs changes should security bugs with set_fs much more
difficult"
* 'exec-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (23 commits)
exec: Implement kernel_execve
exec: Factor bprm_stack_limits out of prepare_arg_pages
exec: Factor bprm_execve out of do_execve_common
exec: Move bprm_mm_init into alloc_bprm
exec: Move initialization of bprm->filename into alloc_bprm
exec: Factor out alloc_bprm
exec: Remove unnecessary spaces from binfmts.h
umd: Stop using split_argv
umd: Remove exit_umh
bpfilter: Take advantage of the facilities of struct pid
exit: Factor thread_group_exited out of pidfd_poll
umd: Track user space drivers with struct pid
bpfilter: Move bpfilter_umh back into init data
exec: Remove do_execve_file
umh: Stop calling do_execve_file
umd: Transform fork_usermode_blob into fork_usermode_driver
umd: Rename umd_info.cmdline umd_info.driver_name
umd: For clarity rename umh_info umd_info
umh: Separate the user mode driver and the user mode helper support
umh: Remove call_usermodehelper_setup_file.
...
Since the parse_args() stops parsing at '--', bootconfig_params()
will never get the '--' as param and initargs_found never be true.
In the result, if we pass some init arguments via the bootconfig,
those are always appended to the kernel command line with '--'
even if the kernel command line already has '--'.
To fix this correctly, check the return value of parse_args()
and set initargs_found true if the return value is not an error
but a valid address.
Link: https://lkml.kernel.org/r/159650953285.270383.14822353843556363851.stgit@devnote2
Fixes: f61872bb58 ("bootconfig: Use parse_args() to find bootconfig and '--'")
Cc: stable@vger.kernel.org
Reported-by: Arvind Sankar <nivedita@alum.mit.edu>
Suggested-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add a simple helper to check if a file exists based on kernel space file
name and switch the early init code over to it. Note that this
theoretically changes behavior as it always is based on the effective
permissions. But during early init that doesn't make a difference.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Set ramdisk_execute_command to "/init" at compile time. The command
line can still override it, but this saves a few instructions and
removes a NULL check.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Don't rely on the implicit set_fs(KERNEL_DS) for ksys_open to work, but
instead open a struct file for /dev/console and then install it as FD
0/1/2 manually.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
To allow the kernel not to play games with set_fs to call exec
implement kernel_execve. The function kernel_execve takes pointers
into kernel memory and copies the values pointed to onto the new
userspace stack.
The calls with arguments from kernel space of do_execve are replaced
with calls to kernel_execve.
The calls do_execve and do_execveat are made static as there are now
no callers outside of exec.
The comments that mention do_execve are updated to refer to
kernel_execve or execve depending on the circumstances. In addition
to correcting the comments, this makes it easy to grep for do_execve
and verify it is not used.
Inspired-by: https://lkml.kernel.org/r/20200627072704.2447163-1-hch@lst.de
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/87wo365ikj.fsf@x220.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
In addition to -ftrivial-auto-var-init=pattern (used by
CONFIG_INIT_STACK_ALL now) Clang also supports zero initialization for
locals enabled by -ftrivial-auto-var-init=zero. The future of this flag
is still being debated (see https://bugs.llvm.org/show_bug.cgi?id=45497).
Right now it is guarded by another flag,
-enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang,
which means it may not be supported by future Clang releases. Another
possible resolution is that -ftrivial-auto-var-init=zero will persist
(as certain users have already started depending on it), but the name
of the guard flag will change.
In the meantime, zero initialization has proven itself as a good
production mitigation measure against uninitialized locals. Unlike pattern
initialization, which has a higher chance of triggering existing bugs,
zero initialization provides safe defaults for strings, pointers, indexes,
and sizes. On the other hand, pattern initialization remains safer for
return values. Chrome OS and Android are moving to using zero
initialization for production builds.
Performance-wise, the difference between pattern and zero initialization
is usually negligible, although the generated code for zero
initialization is more compact.
This patch renames CONFIG_INIT_STACK_ALL to CONFIG_INIT_STACK_ALL_PATTERN
and introduces another config option, CONFIG_INIT_STACK_ALL_ZERO, that
enables zero initialization for locals if the corresponding flags are
supported by Clang.
Cc: Kees Cook <keescook@chromium.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alexander Potapenko <glider@google.com>
Link: https://lore.kernel.org/r/20200616083435.223038-1-glider@google.com
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Merge the state of the locking kcsan branch before the read/write_once()
and the atomics modifications got merged.
Squash the fallout of the rebase on top of the read/write once and atomic
fallback work into the merge. The history of the original branch is
preserved in tag locking-kcsan-2020-06-02.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Patch series "support setting sysctl parameters from kernel command line", v3.
This series adds support for something that seems like many people
always wanted but nobody added it yet, so here's the ability to set
sysctl parameters via kernel command line options in the form of
sysctl.vm.something=1
The important part is Patch 1. The second, not so important part is an
attempt to clean up legacy one-off parameters that do the same thing as
a sysctl. I don't want to remove them completely for compatibility
reasons, but with generic sysctl support the idea is to remove the
one-off param handlers and treat the parameters as aliases for the
sysctl variants.
I have identified several parameters that mention sysctl counterparts in
Documentation/admin-guide/kernel-parameters.txt but there might be more.
The conversion also has varying level of success:
- numa_zonelist_order is converted in Patch 2 together with adding the
necessary infrastructure. It's easy as it doesn't really do anything
but warn on deprecated value these days.
- hung_task_panic is converted in Patch 3, but there's a downside that
now it only accepts 0 and 1, while previously it was any integer
value
- nmi_watchdog maps to two sysctls nmi_watchdog and hardlockup_panic,
so there's no straighforward conversion possible
- traceoff_on_warning is a flag without value and it would be required
to handle that somehow in the conversion infractructure, which seems
pointless for a single flag
This patch (of 5):
A recently proposed patch to add vm_swappiness command line parameter in
addition to existing sysctl [1] made me wonder why we don't have a
general support for passing sysctl parameters via command line.
Googling found only somebody else wondering the same [2], but I haven't
found any prior discussion with reasons why not to do this.
Settings the vm_swappiness issue aside (the underlying issue might be
solved in a different way), quick search of kernel-parameters.txt shows
there are already some that exist as both sysctl and kernel parameter -
hung_task_panic, nmi_watchdog, numa_zonelist_order, traceoff_on_warning.
A general mechanism would remove the need to add more of those one-offs
and might be handy in situations where configuration by e.g.
/etc/sysctl.d/ is impractical.
Hence, this patch adds a new parse_args() pass that looks for parameters
prefixed by 'sysctl.' and tries to interpret them as writes to the
corresponding sys/ files using an temporary in-kernel procfs mount.
This mechanism was suggested by Eric W. Biederman [3], as it handles
all dynamically registered sysctl tables, even though we don't handle
modular sysctls. Errors due to e.g. invalid parameter name or value
are reported in the kernel log.
The processing is hooked right before the init process is loaded, as
some handlers might be more complicated than simple setters and might
need some subsystems to be initialized. At the moment the init process
can be started and eventually execute a process writing to /proc/sys/
then it should be also fine to do that from the kernel.
Sysctls registered later on module load time are not set by this
mechanism - it's expected that in such scenarios, setting sysctl values
from userspace is practical enough.
[1] https://lore.kernel.org/r/BL0PR02MB560167492CA4094C91589930E9FC0@BL0PR02MB5601.namprd02.prod.outlook.com/
[2] https://unix.stackexchange.com/questions/558802/how-to-set-sysctl-using-kernel-command-line-parameter
[3] https://lore.kernel.org/r/87bloj2skm.fsf@x220.int.ebiederm.org/
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Link: http://lkml.kernel.org/r/20200427180433.7029-1-vbabka@suse.cz
Link: http://lkml.kernel.org/r/20200427180433.7029-2-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some init systems (eg. systemd) have init at their own paths, for
example, /usr/lib/systemd/systemd. A compatibility symlink to one of the
hardcoded init paths is provided by another package, usually named
something like systemd-sysvcompat or similar.
Currently distro maintainers who are hands-off on the bootloader are more
or less required to include those compatibility links as part of their
base distribution, because it's hard to migrate away from them since
there's a risk some users will not get the message to set init= on the
kernel command line appropriately.
Moreover, for distributions where the init system is something the
distribution itself is opinionated about (eg. Arch, which has systemd in
the required `base` package), we could usually reasonably configure this
ahead of time when building the distribution kernel. However, we
currently simply don't have any way to configure the kernel to do this.
Here's an example discussion where removing sysvcompat was discussed by
distro maintainers[0].
This patch adds a new Kconfig tunable, CONFIG_DEFAULT_INIT, which if set
is tried before the hardcoded fallback list. So the order of precedence
is now thus:
1. init= on command line (on failure: panic)
2. CONFIG_DEFAULT_INIT (on failure: try #3)
3. Hardcoded fallback list (on failure: panic)
This new config parameter will allow distribution maintainers to move away
from these compatibility links safely, without having to worry that their
users might not have the right init=.
There are also two other benefits of this over having the distribution
maintain a symlink:
1. One of the value propositions over simply having distributions
maintain a /sbin/init symlink via a package is that it also frees
distributions which have a preferred default, but not mandatory, init
system from having their package manager fight with their users for
control of /{s,}bin/init. Instead, the distribution simply makes
their preference known in CONFIG_DEFAULT_INIT, and if the user
installs another init system and uninstalls the default one they can
still make use of /{s,}bin/init and friends for their own uses. This
makes more cases Just Work(tm) without the user having to perform
extra configuration via init=.
2. Since before this we don't know which path the distribution actually
_intends_ to serve init from, we don't pr_err if it is simply
missing, and usually will just silently put the user in a /bin/sh
shell. Now that the distribution can make a declaration of intent, we
can be more vocal when this init system fails to launch for any
reason, even if it's simply because no file exists at that location,
speeding up the palaver of init/mount dependency/etc debugging a bit.
[0]: https://lists.archlinux.org/pipermail/arch-dev-public/2019-January/029435.html
Signed-off-by: Chris Down <chris@chrisdown.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: http://lkml.kernel.org/r/20200522160234.GA1487022@chrisdown.name
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
padata will soon initialize the system's struct pages in parallel, so it
needs to be ready by page_alloc_init_late().
The error return from padata_driver_init() triggers an initcall warning,
so add a warning to padata_init() to avoid silent failure.
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Josh Triplett <josh@joshtriplett.org>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Robert Elliott <elliott@hpe.com>
Cc: Shile Zhang <shile.zhang@linux.alibaba.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Link: http://lkml.kernel.org/r/20200527173608.2885243-3-daniel.m.jordan@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
stack protector enabled.
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Merge tag 'x86_urgent_for_v5.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fix from Borislav Petkov:
"A single fix for early boot crashes of kernels built with gcc10 and
stack protector enabled"
* tag 'x86_urgent_for_v5.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Fix early boot crash on gcc-10, third try
... or the odyssey of trying to disable the stack protector for the
function which generates the stack canary value.
The whole story started with Sergei reporting a boot crash with a kernel
built with gcc-10:
Kernel panic — not syncing: stack-protector: Kernel stack is corrupted in: start_secondary
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc5—00235—gfffb08b37df9 #139
Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./H77M—D3H, BIOS F12 11/14/2013
Call Trace:
dump_stack
panic
? start_secondary
__stack_chk_fail
start_secondary
secondary_startup_64
-—-[ end Kernel panic — not syncing: stack—protector: Kernel stack is corrupted in: start_secondary
This happens because gcc-10 tail-call optimizes the last function call
in start_secondary() - cpu_startup_entry() - and thus emits a stack
canary check which fails because the canary value changes after the
boot_init_stack_canary() call.
To fix that, the initial attempt was to mark the one function which
generates the stack canary with:
__attribute__((optimize("-fno-stack-protector"))) ... start_secondary(void *unused)
however, using the optimize attribute doesn't work cumulatively
as the attribute does not add to but rather replaces previously
supplied optimization options - roughly all -fxxx options.
The key one among them being -fno-omit-frame-pointer and thus leading to
not present frame pointer - frame pointer which the kernel needs.
The next attempt to prevent compilers from tail-call optimizing
the last function call cpu_startup_entry(), shy of carving out
start_secondary() into a separate compilation unit and building it with
-fno-stack-protector, was to add an empty asm("").
This current solution was short and sweet, and reportedly, is supported
by both compilers but we didn't get very far this time: future (LTO?)
optimization passes could potentially eliminate this, which leads us
to the third attempt: having an actual memory barrier there which the
compiler cannot ignore or move around etc.
That should hold for a long time, but hey we said that about the other
two solutions too so...
Reported-by: Sergei Trofimovich <slyfox@gentoo.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Kalle Valo <kvalo@codeaurora.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200314164451.346497-1-slyfox@gentoo.org
Commit de462e5f10 ("bootconfig: Fix to remove bootconfig
data from initrd while boot") causes a cosmetic regression
on dmesg, which warns "no bootconfig data" message without
bootconfig cmdline option.
Fix setup_boot_config() by moving no bootconfig check after
commandline option check.
Link: http://lkml.kernel.org/r/9b1ba335-071d-c983-89a4-2677b522dcc8@molgen.mpg.de
Link: http://lkml.kernel.org/r/158916116468.21787.14558782332170588206.stgit@devnote2
Fixes: de462e5f10 ("bootconfig: Fix to remove bootconfig data from initrd while boot")
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If there is a bootconfig data in the tail of initrd/initramfs,
initrd image sanity check caused an error while decompression
stage as follows.
[ 0.883882] Unpacking initramfs...
[ 2.696429] Initramfs unpacking failed: invalid magic at start of compressed archive
This error will be ignored if CONFIG_BLK_DEV_RAM=n,
but CONFIG_BLK_DEV_RAM=y the kernel failed to mount rootfs
and causes a panic.
To fix this issue, shrink down the initrd_end for removing
tailing bootconfig data while boot the kernel.
Link: http://lkml.kernel.org/r/158788401014.24243.17424755854115077915.stgit@devnote2
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Fixes: 7684b8582c ("bootconfig: Load boot config from the tail of initrd")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Merge tag 'v5.7-rc1' into locking/kcsan, to resolve conflicts and refresh
Resolve these conflicts:
arch/x86/Kconfig
arch/x86/kernel/Makefile
Do a minor "evil merge" to move the KCSAN entry up a bit by a few lines
in the Kconfig to reduce the probability of future conflicts.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
printk_deferred(), similarly to printk_safe/printk_nmi, does not
immediately attempt to print a new message on the consoles, avoiding
calls into non-reentrant kernel paths, e.g. scheduler or timekeeping,
which potentially can deadlock the system.
Those printk() flavors, instead, rely on per-CPU flush irq_work to print
messages from safer contexts. For same reasons (recursive scheduler or
timekeeping calls) printk() uses per-CPU irq_work in order to wake up
user space syslog/kmsg readers.
However, only printk_safe/printk_nmi do make sure that per-CPU areas
have been initialised and that it's safe to modify per-CPU irq_work.
This means that, for instance, should printk_deferred() be invoked "too
early", that is before per-CPU areas are initialised, printk_deferred()
will perform illegal per-CPU access.
Lech Perczak [0] reports that after commit 1b710b1b10 ("char/random:
silence a lockdep splat with printk()") user-space syslog/kmsg readers
are not able to read new kernel messages.
The reason is printk_deferred() being called too early (as was pointed
out by Petr and John).
Fix printk_deferred() and do not queue per-CPU irq_work before per-CPU
areas are initialized.
Link: https://lore.kernel.org/lkml/aa0732c6-5c4e-8a8b-a1c1-75ebe3dca05b@camlintechnologies.com/
Reported-by: Lech Perczak <l.perczak@camlintechnologies.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Jann Horn <jannh@google.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Show line and column when we got a parse error in bootconfig tool.
Current lib/bootconfig shows the parse error with byte offset, but
that is not human readable.
This makes xbc_init() not showing error message itself but able to
pass the error message and position to caller, so that the caller
can decode it and show the error message with line number and columns.
With this patch, bootconfig tool shows an error with line:column as
below.
$ cat samples/bad-dotword.bconf
# do not start keyword with .
key {
.word = 1
}
$ ./bootconfig -a samples/bad-dotword.bconf initrd
Parse Error: Invalid keyword at 3:3
Link: http://lkml.kernel.org/r/158323469002.10560.4023923847704522760.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Change in API of bootconfig (before it comes live in a release)
- Have a magic value "BOOTCONFIG" in initrd to know a bootconfig exists
- Set CONFIG_BOOT_CONFIG to 'n' by default
- Show error if "bootconfig" on cmdline but not compiled in
- Prevent redefining the same value
- Have a way to append values
- Added a SELECT BLK_DEV_INITRD to fix a build failure
Synthetic event fixes:
- Switch to raw_smp_processor_id() for recording CPU value in preempt
section. (No care for what the value actually is)
- Fix samples always recording u64 values
- Fix endianess
- Check number of values matches number of fields
- Fix a printing bug
Fix of trace_printk() breaking postponed start up tests
Make a function static that is only used in a single file.
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Merge tag 'trace-v5.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing and bootconfig updates:
"Fixes and changes to bootconfig before it goes live in a release.
Change in API of bootconfig (before it comes live in a release):
- Have a magic value "BOOTCONFIG" in initrd to know a bootconfig
exists
- Set CONFIG_BOOT_CONFIG to 'n' by default
- Show error if "bootconfig" on cmdline but not compiled in
- Prevent redefining the same value
- Have a way to append values
- Added a SELECT BLK_DEV_INITRD to fix a build failure
Synthetic event fixes:
- Switch to raw_smp_processor_id() for recording CPU value in preempt
section. (No care for what the value actually is)
- Fix samples always recording u64 values
- Fix endianess
- Check number of values matches number of fields
- Fix a printing bug
Fix of trace_printk() breaking postponed start up tests
Make a function static that is only used in a single file"
* tag 'trace-v5.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
bootconfig: Fix CONFIG_BOOTTIME_TRACING dependency issue
bootconfig: Add append value operator support
bootconfig: Prohibit re-defining value on same key
bootconfig: Print array as multiple commands for legacy command line
bootconfig: Reject subkey and value on same parent key
tools/bootconfig: Remove unneeded error message silencer
bootconfig: Add bootconfig magic word for indicating bootconfig explicitly
bootconfig: Set CONFIG_BOOT_CONFIG=n by default
tracing: Clear trace_state when starting trace
bootconfig: Mark boot_config_checksum() static
tracing: Disable trace_printk() on post poned tests
tracing: Have synthetic event test use raw_smp_processor_id()
tracing: Fix number printing bug in print_synth_event()
tracing: Check that number of vals matches number of synth event fields
tracing: Make synth_event trace functions endian-correct
tracing: Make sure synth_event_trace() example always uses u64
Print arraied values as multiple same options for legacy
kernel command line. With this rule, if the "kernel.*" and
"init.*" array entries in bootconfig are printed out as
multiple same options, e.g.
kernel {
console = "ttyS0,115200"
console += "tty0"
}
will be correctly converted to
console="ttyS0,115200" console="tty0"
in the kernel command line.
Link: http://lkml.kernel.org/r/158220118213.26565.8163300497009463916.stgit@devnote2
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add bootconfig magic word to the end of bootconfig on initrd
image for indicating explicitly the bootconfig is there.
Also tools/bootconfig treats wrong size or wrong checksum or
parse error as an error, because if there is a bootconfig magic
word, there must be a bootconfig.
The bootconfig magic word is "#BOOTCONFIG\n", 12 bytes word.
Thus the block image of the initrd file with bootconfig is
as follows.
[Initrd][bootconfig][size][csum][#BOOTCONFIG\n]
Link: http://lkml.kernel.org/r/158220112263.26565.3944814205960612841.stgit@devnote2
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Set CONFIG_BOOT_CONFIG=n by default. This also warns
user if CONFIG_BOOT_CONFIG=n but "bootconfig" is given
in the kernel command line.
Link: http://lkml.kernel.org/r/158220111291.26565.9036889083940367969.stgit@devnote2
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In fact, this function is only used in this file, so mark it with 'static'.
Link: http://lkml.kernel.org/r/1581852511-14163-1-git-send-email-hqjagain@gmail.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
- Fix an uninitialized variable
- Fix compile bug to bootconfig userspace tool (in tools directory)
- Suppress some error messages of bootconfig userspace tool
- Remove unneded CONFIG_LIBXBC from bootconfig
- Allocate bootconfig xbc_nodes dynamically.
To ease complaints about taking up static memory at boot up
- Use of parse_args() to parse bootconfig instead of strstr() usage
Prevents issues of double quotes containing the interested string
- Fix missing ring_buffer_nest_end() on synthetic event error path
- Return zero not -EINVAL on soft disabled synthetic event
(soft disabling must be the same as hard disabling, which returns zero)
- Consolidate synthetic event code (remove duplicate code)
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Merge tag 'trace-v5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Various fixes:
- Fix an uninitialized variable
- Fix compile bug to bootconfig userspace tool (in tools directory)
- Suppress some error messages of bootconfig userspace tool
- Remove unneded CONFIG_LIBXBC from bootconfig
- Allocate bootconfig xbc_nodes dynamically. To ease complaints about
taking up static memory at boot up
- Use of parse_args() to parse bootconfig instead of strstr() usage
Prevents issues of double quotes containing the interested string
- Fix missing ring_buffer_nest_end() on synthetic event error path
- Return zero not -EINVAL on soft disabled synthetic event (soft
disabling must be the same as hard disabling, which returns zero)
- Consolidate synthetic event code (remove duplicate code)"
* tag 'trace-v5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Consolidate trace() functions
tracing: Don't return -EINVAL when tracing soft disabled synth events
tracing: Add missing nest end to synth_event_trace_start() error case
tools/bootconfig: Suppress non-error messages
bootconfig: Allocate xbc_nodes array dynamically
bootconfig: Use parse_args() to find bootconfig and '--'
tracing/kprobe: Fix uninitialized variable bug
bootconfig: Remove unneeded CONFIG_LIBXBC
tools/bootconfig: Fix wrong __VA_ARGS__ usage
The current implementation does a naive search of "bootconfig" on the kernel
command line. But this could find "bootconfig" that is part of another
option in quotes (although highly unlikely). But it also needs to find '--'
on the kernel command line to know if it should append a '--' or not when a
bootconfig in the initrd file has an "init" section. The check uses the
naive strstr() to find to see if it exists. But this can return a false
positive if it exists in an option and then the "init" section in the initrd
will not be appended properly.
Using parse_args() to find both of these will solve both of these problems.
Link: https://lore.kernel.org/r/202002070954.C18E7F58B@keescook
Fixes: 7495e0926f ("bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline")
Fixes: 1319916209 ("bootconfig: init: Allow admin to use bootconfig for init command line")
Reported-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
- Added new "bootconfig".
Looks for a file appended to initrd to add boot config options.
This has been discussed thoroughly at Linux Plumbers.
Very useful for adding kprobes at bootup.
Only enabled if "bootconfig" is on the real kernel command line.
- Created dynamic event creation.
Merges common code between creating synthetic events and
kprobe events.
- Rename perf "ring_buffer" structure to "perf_buffer"
- Rename ftrace "ring_buffer" structure to "trace_buffer"
Had to rename existing "trace_buffer" to "array_buffer"
- Allow trace_printk() to work withing (some) tracing code.
- Sort of tracing configs to be a little better organized
- Fixed bug where ftrace_graph hash was not being protected properly
- Various other small fixes and clean ups
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Merge tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
- Added new "bootconfig".
This looks for a file appended to initrd to add boot config options,
and has been discussed thoroughly at Linux Plumbers.
Very useful for adding kprobes at bootup.
Only enabled if "bootconfig" is on the real kernel command line.
- Created dynamic event creation.
Merges common code between creating synthetic events and kprobe
events.
- Rename perf "ring_buffer" structure to "perf_buffer"
- Rename ftrace "ring_buffer" structure to "trace_buffer"
Had to rename existing "trace_buffer" to "array_buffer"
- Allow trace_printk() to work withing (some) tracing code.
- Sort of tracing configs to be a little better organized
- Fixed bug where ftrace_graph hash was not being protected properly
- Various other small fixes and clean ups
* tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (88 commits)
bootconfig: Show the number of nodes on boot message
tools/bootconfig: Show the number of bootconfig nodes
bootconfig: Add more parse error messages
bootconfig: Use bootconfig instead of boot config
ftrace: Protect ftrace_graph_hash with ftrace_sync
ftrace: Add comment to why rcu_dereference_sched() is open coded
tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu
tracing: Annotate ftrace_graph_hash pointer with __rcu
bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline
tracing: Use seq_buf for building dynevent_cmd string
tracing: Remove useless code in dynevent_arg_pair_add()
tracing: Remove check_arg() callbacks from dynevent args
tracing: Consolidate some synth_event_trace code
tracing: Fix now invalid var_ref_vals assumption in trace action
tracing: Change trace_boot to use synth_event interface
tracing: Move tracing selftests to bottom of menu
tracing: Move mmio tracer config up with the other tracers
tracing: Move tracing test module configs together
tracing: Move all function tracing configs together
tracing: Documentation for in-kernel synthetic event API
...
As the bootconfig is appended to the initrd it is not as easy to modify as
the kernel command line. If there's some issue with the kernel, and the
developer wants to boot a pristine kernel, it should not be needed to modify
the initrd to remove the bootconfig for a single boot.
As bootconfig is silently added (if the admin does not know where to look
they may not know it's being loaded). It should be explicitly added to the
kernel cmdline. The loading of the bootconfig is only done if "bootconfig"
is on the kernel command line. This will let admins know that the kernel
command line is extended.
Note, after adding printk()s for when the size is too great or the checksum
is wrong, exposed that the current method always looked for the boot config,
and if this size and checksum matched, it would parse it (as if either is
wrong a printk has been added to show this). It's better to only check this
if the boot config is asked to be looked for.
Link: https://lore.kernel.org/r/CAHk-=wjfjO+h6bQzrTf=YCZA53Y3EDyAs3Z4gEsT7icA3u_Psw@mail.gmail.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This message leads to thinking that memory protection is not implemented
for the said architecture, whereas absence of CONFIG_STRICT_KERNEL_RWX
only means that memory protection has not been selected at compile time.
Don't print this message when CONFIG_ARCH_HAS_STRICT_KERNEL_RWX is
selected by the architecture. Instead, print "Kernel memory protection
not selected by kernel config."
Link: http://lkml.kernel.org/r/62477e446d9685459d4f27d193af6ff1bd69d55f.1578557581.git.christophe.leroy@c-s.fr
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "init/main.c: minor cleanup/bugfix of envvar handling", v2.
unknown_bootoption passes unrecognized command line arguments to init as
either environment variables or arguments. Some of the logic in the
function is broken for quoted command line arguments.
When an argument of the form param="value" is processed by parse_args
and passed to unknown_bootoption, the command line has
param\0"value\0
with val pointing to the beginning of value. The helper function
repair_env_string is then used to restore the '=' character that was
removed by parse_args, and strip the quotes off fully. This results in
param=value\0\0
and val ends up pointing to the 'a' instead of the 'v' in value. This
bug was introduced when repair_env_string was refactored into a separate
function, and the decrement of val in repair_env_string became dead
code.
This causes two problems in unknown_bootoption in the two places where
the val pointer is used as a substitute for the length of param:
1. An argument of the form param=".value" is misinterpreted as a
potential module parameter, with the result that it will not be
placed in init's environment.
2. An argument of the form param="value" is checked to see if param is
an existing environment variable that should be overwritten, but the
comparison is off-by-one and compares 'param=v' instead of 'param='
against the existing environment. So passing, for example,
TERM="vt100" on the command line results in init being passed both
TERM=linux and TERM=vt100 in its environment.
Patch 1 adds logging for the arguments and environment passed to init
and is independent of the rest: it can be dropped if this is
unnecessarily verbose.
Patch 2 removes repair_env_string from initcall parameter parsing in
do_initcall_level, as that uses a separate copy of the command line now
and the repairing is no longer necessary.
Patch 3 fixes the bug in unknown_bootoption by recording the length of
param explicitly instead of implying it from val-param.
This patch (of 3):
Commit a99cd11251 ("init: fix bug where environment vars can't be
passed via boot args") introduced two minor bugs in unknown_bootoption
by factoring out the quoted value handling into a separate function.
When value is quoted, repair_env_string will move the value up 1 byte to
strip the quotes, so val in unknown_bootoption no longer points to the
actual location of the value.
The result is that an argument of the form param=".value" is mistakenly
treated as a potential module parameter and is not placed in init's
environment, and an argument of the form param="value" can result in a
duplicate environment variable: eg TERM="vt100" on the command line will
result in both TERM=linux and TERM=vt100 being placed into init's
environment.
Fix this by recording the length of the param before calling
repair_env_string instead of relying on val.
Link: http://lkml.kernel.org/r/20191212180023.24339-4-nivedita@alum.mit.edu
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
