572 Commits

Author SHA1 Message Date
Christoph Hellwig
7ac68b2a59 modules: only allow symbol_get of EXPORT_SYMBOL_GPL modules
commit 9011e49d54dcc7653ebb8a1e05b5badb5ecfa9f9 upstream.

It has recently come to my attention that nvidia is circumventing the
protection added in 262e6ae7081d ("modules: inherit
TAINT_PROPRIETARY_MODULE") by importing exports from their proprietary
modules into an allegedly GPL licensed module and then rexporting them.

Given that symbol_get was only ever intended for tightly cooperating
modules using very internal symbols it is logical to restrict it to
being used on EXPORT_SYMBOL_GPL and prevent nvidia from costly DMCA
Circumvention of Access Controls law suites.

All symbols except for four used through symbol_get were already exported
as EXPORT_SYMBOL_GPL, and the remaining four ones were switched over in
the preparation patches.

Fixes: 262e6ae7081d ("modules: inherit TAINT_PROPRIETARY_MODULE")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-23 10:47:56 +02:00
Petr Pavlu
008368a9b4 module: Don't wait for GOING modules
commit 0254127ab977e70798707a7a2b757c9f3c971210 upstream.

During a system boot, it can happen that the kernel receives a burst of
requests to insert the same module but loading it eventually fails
during its init call. For instance, udev can make a request to insert
a frequency module for each individual CPU when another frequency module
is already loaded which causes the init function of the new module to
return an error.

Since commit 6e6de3dee51a ("kernel/module.c: Only return -EEXIST for
modules that have finished loading"), the kernel waits for modules in
MODULE_STATE_GOING state to finish unloading before making another
attempt to load the same module.

This creates unnecessary work in the described scenario and delays the
boot. In the worst case, it can prevent udev from loading drivers for
other devices and might cause timeouts of services waiting on them and
subsequently a failed boot.

This patch attempts a different solution for the problem 6e6de3dee51a
was trying to solve. Rather than waiting for the unloading to complete,
it returns a different error code (-EBUSY) for modules in the GOING
state. This should avoid the error situation that was described in
6e6de3dee51a (user space attempting to load a dependent module because
the -EEXIST error code would suggest to user space that the first module
had been loaded successfully), while avoiding the delay situation too.

This has been tested on linux-next since December 2022 and passes
all kmod selftests except test 0009 with module compression enabled
but it has been confirmed that this issue has existed and has gone
unnoticed since prior to this commit and can also be reproduced without
module compression with a simple usleep(5000000) on tools/modprobe.c [0].
These failures are caused by hitting the kernel mod_concurrent_max and can
happen either due to a self inflicted kernel module auto-loead DoS somehow
or on a system with large CPU count and each CPU count incorrectly triggering
many module auto-loads. Both of those issues need to be fixed in-kernel.

[0] https://lore.kernel.org/all/Y9A4fiobL6IHp%2F%2FP@bombadil.infradead.org/

Fixes: 6e6de3dee51a ("kernel/module.c: Only return -EEXIST for modules that have finished loading")
Co-developed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: Petr Mladek <pmladek@suse.com>
[mcgrof: enhance commit log with testing and kmod test result interpretation ]
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-06 07:49:41 +01:00
Igor Pylypiv
a0c66ac8b7 Revert "module, async: async_synchronize_full() on module init iff async is used"
[ Upstream commit 67d6212afda218d564890d1674bab28e8612170f ]

This reverts commit 774a1221e862b343388347bac9b318767336b20b.

We need to finish all async code before the module init sequence is
done.  In the reverted commit the PF_USED_ASYNC flag was added to mark a
thread that called async_schedule().  Then the PF_USED_ASYNC flag was
used to determine whether or not async_synchronize_full() needs to be
invoked.  This works when modprobe thread is calling async_schedule(),
but it does not work if module dispatches init code to a worker thread
which then calls async_schedule().

For example, PCI driver probing is invoked from a worker thread based on
a node where device is attached:

	if (cpu < nr_cpu_ids)
		error = work_on_cpu(cpu, local_pci_probe, &ddi);
	else
		error = local_pci_probe(&ddi);

We end up in a situation where a worker thread gets the PF_USED_ASYNC
flag set instead of the modprobe thread.  As a result,
async_synchronize_full() is not invoked and modprobe completes without
waiting for the async code to finish.

The issue was discovered while loading the pm80xx driver:
(scsi_mod.scan=async)

modprobe pm80xx                      worker
...
  do_init_module()
  ...
    pci_call_probe()
      work_on_cpu(local_pci_probe)
                                     local_pci_probe()
                                       pm8001_pci_probe()
                                         scsi_scan_host()
                                           async_schedule()
                                           worker->flags |= PF_USED_ASYNC;
                                     ...
      < return from worker >
  ...
  if (current->flags & PF_USED_ASYNC) <--- false
  	async_synchronize_full();

Commit 21c3c5d28007 ("block: don't request module during elevator init")
fixed the deadlock issue which the reverted commit 774a1221e862
("module, async: async_synchronize_full() on module init iff async is
used") tried to fix.

Since commit 0fdff3ec6d87 ("async, kmod: warn on synchronous
request_module() from async workers") synchronous module loading from
async is not allowed.

Given that the original deadlock issue is fixed and it is no longer
allowed to call synchronous request_module() from async we can remove
PF_USED_ASYNC flag to make module init consistently invoke
async_synchronize_full() unless async module probe is requested.

Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
Reviewed-by: Changyuan Lyu <changyuanl@google.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-02-23 11:58:38 +01:00
Mimi Zohar
ff66086362 module: limit enabling module.sig_enforce
[ Upstream commit 0c18f29aae7ce3dadd26d8ee3505d07cc982df75 ]

Irrespective as to whether CONFIG_MODULE_SIG is configured, specifying
"module.sig_enforce=1" on the boot command line sets "sig_enforce".
Only allow "sig_enforce" to be set when CONFIG_MODULE_SIG is configured.

This patch makes the presence of /sys/module/module/parameters/sig_enforce
dependent on CONFIG_MODULE_SIG=y.

Fixes: fda784e50aac ("module: export module signature enforcement status")
Reported-by: Nayna Jain <nayna@linux.ibm.com>
Tested-by: Mimi Zohar <zohar@linux.ibm.com>
Tested-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-30 08:48:28 -04:00
Christoph Hellwig
2ab98abf0d modules: inherit TAINT_PROPRIETARY_MODULE
commit 262e6ae7081df304fc625cf368d5c2cbba2bb991 upstream.

If a TAINT_PROPRIETARY_MODULE exports symbol, inherit the taint flag
for all modules importing these symbols, and don't allow loading
symbols from TAINT_PROPRIETARY_MODULE modules if the module previously
imported gplonly symbols.  Add a anti-circumvention devices so people
don't accidentally get themselves into trouble this way.

Comment from Greg:
  "Ah, the proven-to-be-illegal "GPL Condom" defense :)"

[jeyu: pr_info -> pr_err and pr_warn as per discussion]
Link: http://lore.kernel.org/r/20200730162957.GA22469@lst.de
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:59:23 +02:00
Christoph Hellwig
ef658fe020 modules: return licensing information from find_symbol
commit ef1dac6021cc8ec5de02ce31722bf26ac4ed5523 upstream.

Report the GPLONLY status through a new argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:59:23 +02:00
Christoph Hellwig
04c85f7588 modules: rename the licence field in struct symsearch to license
commit cd8732cdcc37d7077c4fa2c966b748c0662b607e upstream.

Use the same spelling variant as the rest of the file.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:59:23 +02:00
Christoph Hellwig
27b700c232 modules: unexport __module_address
commit 34e64705ad415ed7a816e60ef62b42fe6d1729d9 upstream.

__module_address is only used by built-in code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:59:23 +02:00
Christoph Hellwig
d338108ac1 modules: unexport __module_text_address
commit 3fe1e56d0e68b623dd62d8d38265d2a052e7e185 upstream.

__module_text_address is only used by built-in code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:59:23 +02:00
Christoph Hellwig
1c713f50b3 modules: mark each_symbol_section static
commit a54e04914c211b5678602a46b3ede5d82ec1327d upstream.

each_symbol_section is only used inside of module.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:59:23 +02:00
Christoph Hellwig
c3da81cefb modules: mark find_symbol static
commit 773110470e2fa3839523384ae014f8a723c4d178 upstream.

find_symbol is only used in module.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:59:23 +02:00
Christoph Hellwig
8745aa4e01 modules: mark ref_module static
commit 7ef5264de773279b9f23b6cc8afb5addb30e970b upstream.

ref_module isn't used anywhere outside of module.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:59:23 +02:00
Fangrui Song
8697aa8614 module: Ignore _GLOBAL_OFFSET_TABLE_ when warning for undefined symbols
commit ebfac7b778fac8b0e8e92ec91d0b055f046b4604 upstream.

clang-12 -fno-pic (since
a084c0388e)
can emit `call __stack_chk_fail@PLT` instead of `call __stack_chk_fail`
on x86.  The two forms should have identical behaviors on x86-64 but the
former causes GNU as<2.37 to produce an unreferenced undefined symbol
_GLOBAL_OFFSET_TABLE_.

(On x86-32, there is an R_386_PC32 vs R_386_PLT32 difference but the
linker behavior is identical as far as Linux kernel is concerned.)

Simply ignore _GLOBAL_OFFSET_TABLE_ for now, like what
scripts/mod/modpost.c:ignore_undef_symbol does. This also fixes the
problem for gcc/clang -fpie and -fpic, which may emit `call foo@PLT` for
external function calls on x86.

Note: ld -z defs and dynamic loaders do not error for unreferenced
undefined symbols so the module loader is reading too much.  If we ever
need to ignore more symbols, the code should be refactored to ignore
unreferenced symbols.

Cc: <stable@vger.kernel.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/1250
Link: https://sourceware.org/bugzilla/show_bug.cgi?id=27178
Reported-by: Marco Elver <elver@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Marco Elver <elver@google.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 09:39:56 +01:00
Jessica Yu
7492543050 module: delay kobject uevent until after module init call
[ Upstream commit 38dc717e97153e46375ee21797aa54777e5498f3 ]

Apparently there has been a longstanding race between udev/systemd and
the module loader. Currently, the module loader sends a uevent right
after sysfs initialization, but before the module calls its init
function. However, some udev rules expect that the module has
initialized already upon receiving the uevent.

This race has been triggered recently (see link in references) in some
systemd mount unit files. For instance, the configfs module creates the
/sys/kernel/config mount point in its init function, however the module
loader issues the uevent before this happens. sys-kernel-config.mount
expects to be able to mount /sys/kernel/config upon receipt of the
module loading uevent, but if the configfs module has not called its
init function yet, then this directory will not exist and the mount unit
fails. A similar situation exists for sys-fs-fuse-connections.mount, as
the fuse sysfs mount point is created during the fuse module's init
function. If udev is faster than module initialization then the mount
unit would fail in a similar fashion.

To fix this race, delay the module KOBJ_ADD uevent until after the
module has finished calling its init routine.

References: https://github.com/systemd/systemd/issues/17586
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-By: Nicolas Morey-Chaisemartin <nmoreychaisemartin@suse.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06 14:45:01 +01:00
Miroslav Benes
bea7f4d1ff module: set MODULE_STATE_GOING state when a module fails to load
[ Upstream commit 5e8ed280dab9eeabc1ba0b2db5dbe9fe6debb6b5 ]

If a module fails to load due to an error in prepare_coming_module(),
the following error handling in load_module() runs with
MODULE_STATE_COMING in module's state. Fix it by correctly setting
MODULE_STATE_GOING under "bug_cleanup" label.

Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06 14:45:01 +01:00
Kees Cook
cec9fbfe39 module: Correctly truncate sysfs sections output
commit 11990a5bd7e558e9203c1070fc52fb6f0488e75b upstream.

The only-root-readable /sys/module/$module/sections/$section files
did not truncate their output to the available buffer size. While most
paths into the kernfs read handlers end up using PAGE_SIZE buffers,
it's possible to get there through other paths (e.g. splice, sendfile).
Actually limit the output to the "count" passed into the read function,
and report it back correctly. *sigh*

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/20200805002015.GE23458@shao2-debian
Fixes: ed66f991bb19 ("module: Refactor section attr into bin attribute")
Cc: stable@vger.kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 11:05:34 +02:00
Kees Cook
c744568a5c module: Do not expose section addresses to non-CAP_SYSLOG
commit b25a7c5af9051850d4f3d93ca500056ab6ec724b upstream.

The printing of section addresses in /sys/module/*/sections/* was not
using the correct credentials to evaluate visibility.

Before:

 # cat /sys/module/*/sections/.*text
 0xffffffffc0458000
 ...
 # capsh --drop=CAP_SYSLOG -- -c "cat /sys/module/*/sections/.*text"
 0xffffffffc0458000
 ...

After:

 # cat /sys/module/*/sections/*.text
 0xffffffffc0458000
 ...
 # capsh --drop=CAP_SYSLOG -- -c "cat /sys/module/*/sections/.*text"
 0x0000000000000000
 ...

Additionally replaces the existing (safe) /proc/modules check with
file->f_cred for consistency.

Reported-by: Dominik Czarnota <dominik.czarnota@trailofbits.com>
Fixes: be71eda5383f ("module: Fix display of wrong module .text address")
Cc: stable@vger.kernel.org
Tested-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-16 08:17:26 +02:00
Kees Cook
bbd10824d8 module: Refactor section attr into bin attribute
commit ed66f991bb19d94cae5d38f77de81f96aac7813f upstream.

In order to gain access to the open file's f_cred for kallsym visibility
permission checks, refactor the module section attributes to use the
bin_attribute instead of attribute interface. Additionally removes the
redundant "name" struct member.

Cc: stable@vger.kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-16 08:17:26 +02:00
Gustavo A. R. Silva
2bcda8386a kernel: module: Use struct_size() helper
commit 8d1b73dd25ff92c3fa9807a20c22fa2b44c07336 upstream.

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct module_sect_attrs {
	...
        struct module_sect_attr attrs[0];
};

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

So, replace the following form:

sizeof(*sect_attrs) + nloaded * sizeof(sect_attrs->attrs[0]

with:

struct_size(sect_attrs, attrs, nloaded)

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-16 08:17:26 +02:00
Kees Cook
ebce5c1fb5 kallsyms: Refactor kallsyms_show_value() to take cred
commit 160251842cd35a75edfb0a1d76afa3eb674ff40a upstream.

In order to perform future tests against the cred saved during open(),
switch kallsyms_show_value() to operate on a cred, and have all current
callers pass current_cred(). This makes it very obvious where callers
are checking the wrong credential in their "read" contexts. These will
be fixed in the coming patches.

Additionally switch return value to bool, since it is always used as a
direct permission check, not a 0-on-success, negative-on-error style
function return.

Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-16 08:17:26 +02:00
Jessica Yu
c371b1e41f module: avoid setting info->name early in case we can fall back to info->mod->name
[ Upstream commit 708e0ada1916be765b7faa58854062f2bc620bbf ]

In setup_load_info(), info->name (which contains the name of the module,
mostly used for early logging purposes before the module gets set up)
gets unconditionally assigned if .modinfo is missing despite the fact
that there is an if (!info->name) check near the end of the function.
Avoid assigning a placeholder string to info->name if .modinfo doesn't
exist, so that we can fall back to info->mod->name later on.

Fixes: 5fdc7db6448a ("module: setup load info before module_sig_check()")
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24 08:34:49 +01:00
YueHaibing
bdfaaf35ac kernel/module: Fix memleak in module_add_modinfo_attrs()
[ Upstream commit f6d061d617124abbd55396a3bc37b9bf7d33233c ]

In module_add_modinfo_attrs() if sysfs_create_file() fails
on the first iteration of the loop (so i = 0), we forget to
free the modinfo_attrs.

Fixes: bc6f2a757d52 ("kernel/module: Fix mem leak in module_add_modinfo_attrs")
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-11 04:33:50 -08:00
Konstantin Khorenko
12c88d91a8 kernel/module.c: wakeup processes in module_wq on module unload
[ Upstream commit 5d603311615f612320bb77bd2a82553ef1ced5b7 ]

Fix the race between load and unload a kernel module.

sys_delete_module()
 try_stop_module()
  mod->state = _GOING
					add_unformed_module()
					 old = find_module_all()
					 (old->state == _GOING =>
					  wait_event_interruptible())

					 During pre-condition
					 finished_loading() rets 0
					 schedule()
					 (never gets waken up later)
 free_module()
  mod->state = _UNFORMED
   list_del_rcu(&mod->list)
   (dels mod from "modules" list)

return

The race above leads to modprobe hanging forever on loading
a module.

Error paths on loading module call wake_up_all(&module_wq) after
freeing module, so let's do the same on straight module unload.

Fixes: 6e6de3dee51a ("kernel/module.c: Only return -EEXIST for modules that have finished loading")
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-17 20:35:57 +01:00
Yang Yingliang
52bfcc9c84 modules: fix compile error if don't have strict module rwx
commit 93651f80dcb616b8c9115cdafc8e57a781af22d0 upstream.

If CONFIG_ARCH_HAS_STRICT_MODULE_RWX is not defined,
we need stub for module_enable_nx() and module_enable_x().

If CONFIG_ARCH_HAS_STRICT_MODULE_RWX is defined, but
CONFIG_STRICT_MODULE_RWX is disabled, we need stub for
module_enable_nx.

Move frob_text() outside of the CONFIG_STRICT_MODULE_RWX,
because it is needed anyway.

Fixes: 2eef1399a866 ("modules: fix BUG when load module with rodata=n")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-19 09:09:40 +02:00
Yang Yingliang
ae415d7a27 modules: fix BUG when load module with rodata=n
commit 2eef1399a866c57687962e15142b141a4f8e7862 upstream.

When loading a module with rodata=n, it causes an executing
NX-protected page BUG.

[   32.379191] kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
[   32.382917] BUG: unable to handle page fault for address: ffffffffc0005000
[   32.385947] #PF: supervisor instruction fetch in kernel mode
[   32.387662] #PF: error_code(0x0011) - permissions violation
[   32.389352] PGD 240c067 P4D 240c067 PUD 240e067 PMD 421a52067 PTE 8000000421a53063
[   32.391396] Oops: 0011 [#1] SMP PTI
[   32.392478] CPU: 7 PID: 2697 Comm: insmod Tainted: G           O      5.2.0-rc5+ #202
[   32.394588] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[   32.398157] RIP: 0010:ko_test_init+0x0/0x1000 [ko_test]
[   32.399662] Code: Bad RIP value.
[   32.400621] RSP: 0018:ffffc900029f3ca8 EFLAGS: 00010246
[   32.402171] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[   32.404332] RDX: 00000000000004c7 RSI: 0000000000000cc0 RDI: ffffffffc0005000
[   32.406347] RBP: ffffffffc0005000 R08: ffff88842fbebc40 R09: ffffffff810ede4a
[   32.408392] R10: ffffea00108e3480 R11: 0000000000000000 R12: ffff88842bee21a0
[   32.410472] R13: 0000000000000001 R14: 0000000000000001 R15: ffffc900029f3e78
[   32.412609] FS:  00007fb4f0c0a700(0000) GS:ffff88842fbc0000(0000) knlGS:0000000000000000
[   32.414722] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   32.416290] CR2: ffffffffc0004fd6 CR3: 0000000421a90004 CR4: 0000000000020ee0
[   32.418471] Call Trace:
[   32.419136]  do_one_initcall+0x41/0x1df
[   32.420199]  ? _cond_resched+0x10/0x40
[   32.421433]  ? kmem_cache_alloc_trace+0x36/0x160
[   32.422827]  do_init_module+0x56/0x1f7
[   32.423946]  load_module+0x1e67/0x2580
[   32.424947]  ? __alloc_pages_nodemask+0x150/0x2c0
[   32.426413]  ? map_vm_area+0x2d/0x40
[   32.427530]  ? __vmalloc_node_range+0x1ef/0x260
[   32.428850]  ? __do_sys_init_module+0x135/0x170
[   32.430060]  ? _cond_resched+0x10/0x40
[   32.431249]  __do_sys_init_module+0x135/0x170
[   32.432547]  do_syscall_64+0x43/0x120
[   32.433853]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Because if rodata=n, set_memory_x() can't be called, fix this by
calling set_memory_x in complete_formation();

Fixes: f2c65fb3221a ("x86/modules: Avoid breaking W^X while loading modules")
Suggested-by: Jian Cheng <cj.chengjian@huawei.com>
Reviewed-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-19 09:09:40 +02:00
YueHaibing
3015291b2f kernel/module: Fix mem leak in module_add_modinfo_attrs
[ Upstream commit bc6f2a757d525e001268c3658bd88822e768f8db ]

In module_add_modinfo_attrs if sysfs_create_file
fails, we forget to free allocated modinfo_attrs
and roll back the sysfs files.

Fixes: 03e88ae1b13d ("[PATCH] fix module sysfs files reference counting")
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16 08:21:45 +02:00
Jessica Yu
9c49f7811f modules: always page-align module section allocations
[ Upstream commit 38f054d549a869f22a02224cd276a27bf14b6171 ]

Some arches (e.g., arm64, x86) have moved towards non-executable
module_alloc() allocations for security hardening reasons. That means
that the module loader will need to set the text section of a module to
executable, regardless of whether or not CONFIG_STRICT_MODULE_RWX is set.

When CONFIG_STRICT_MODULE_RWX=y, module section allocations are always
page-aligned to handle memory rwx permissions. On some arches with
CONFIG_STRICT_MODULE_RWX=n however, when setting the module text to
executable, the BUG_ON() in frob_text() gets triggered since module
section allocations are not page-aligned when CONFIG_STRICT_MODULE_RWX=n.
Since the set_memory_* API works with pages, and since we need to call
set_memory_x() regardless of whether CONFIG_STRICT_MODULE_RWX is set, we
might as well page-align all module section allocations for ease of
managing rwx permissions of module sections (text, rodata, etc).

Fixes: 2eef1399a866 ("modules: fix BUG when load module with rodata=n")
Reported-by: Martin Kaiser <lists@kaiser.cx>
Reported-by: Bartosz Golaszewski <brgl@bgdev.pl>
Tested-by: David Lechner <david@lechnology.com>
Tested-by: Martin Kaiser <martin@kaiser.cx>
Tested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16 08:21:45 +02:00
Prarit Bhargava
09ec6c6783 kernel/module.c: Only return -EEXIST for modules that have finished loading
[ Upstream commit 6e6de3dee51a439f76eb73c22ae2ffd2c9384712 ]

Microsoft HyperV disables the X86_FEATURE_SMCA bit on AMD systems, and
linux guests boot with repeated errors:

amd64_edac_mod: Unknown symbol amd_unregister_ecc_decoder (err -2)
amd64_edac_mod: Unknown symbol amd_register_ecc_decoder (err -2)
amd64_edac_mod: Unknown symbol amd_report_gart_errors (err -2)
amd64_edac_mod: Unknown symbol amd_unregister_ecc_decoder (err -2)
amd64_edac_mod: Unknown symbol amd_register_ecc_decoder (err -2)
amd64_edac_mod: Unknown symbol amd_report_gart_errors (err -2)

The warnings occur because the module code erroneously returns -EEXIST
for modules that have failed to load and are in the process of being
removed from the module list.

module amd64_edac_mod has a dependency on module edac_mce_amd.  Using
modules.dep, systemd will load edac_mce_amd for every request of
amd64_edac_mod.  When the edac_mce_amd module loads, the module has
state MODULE_STATE_UNFORMED and once the module load fails and the state
becomes MODULE_STATE_GOING.  Another request for edac_mce_amd module
executes and add_unformed_module() will erroneously return -EEXIST even
though the previous instance of edac_mce_amd has MODULE_STATE_GOING.
Upon receiving -EEXIST, systemd attempts to load amd64_edac_mod, which
fails because of unknown symbols from edac_mce_amd.

add_unformed_module() must wait to return for any case other than
MODULE_STATE_LIVE to prevent a race between multiple loads of
dependent modules.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Barret Rhoden <brho@google.com>
Cc: David Arcari <darcari@redhat.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-06 19:06:47 +02:00
Masahiro Yamada
0276ebf166 jump_label: move 'asm goto' support test to Kconfig
commit e9666d10a5677a494260d60d1fa0b73cc7646eb3 upstream.

Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".

The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:

  #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
  # define HAVE_JUMP_LABEL
  #endif

We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.

Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
[nc: Fix trivial conflicts in 4.19
     arch/xtensa/kernel/jump_label.c doesn't exist yet
     Ensured CC_HAVE_ASM_GOTO and HAVE_JUMP_LABEL were sufficiently
     eliminated]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-04 08:02:34 +02:00
Nadav Amit
8715ce033e x86/modules: Avoid breaking W^X while loading modules
[ Upstream commit f2c65fb3221adc6b73b0549fc7ba892022db9797 ]

When modules and BPF filters are loaded, there is a time window in
which some memory is both writable and executable. An attacker that has
already found another vulnerability (e.g., a dangling pointer) might be
able to exploit this behavior to overwrite kernel code. Prevent having
writable executable PTEs in this stage.

In addition, avoiding having W+X mappings can also slightly simplify the
patching of modules code on initialization (e.g., by alternatives and
static-key), as would be done in the next patch. This was actually the
main motivation for this patch.

To avoid having W+X mappings, set them initially as RW (NX) and after
they are set as RO set them as X as well. Setting them as executable is
done as a separate step to avoid one core in which the old PTE is cached
(hence writable), and another which sees the updated PTE (executable),
which would break the W^X protection.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Suggested-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <akpm@linux-foundation.org>
Cc: <ard.biesheuvel@linaro.org>
Cc: <deneen.t.dock@intel.com>
Cc: <kernel-hardening@lists.openwall.com>
Cc: <kristen@linux.intel.com>
Cc: <linux_dti@icloud.com>
Cc: <will.deacon@arm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: https://lkml.kernel.org/r/20190426001143.4983-12-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31 06:46:12 -07:00
Peter Rajnoha
f7debeebcd kobject: return error code if writing /sys/.../uevent fails
[ Upstream commit df44b479654f62b478c18ee4d8bc4e9f897a9844 ]

Propagate error code back to userspace if writing the /sys/.../uevent
file fails. Before, the write operation always returned with success,
even if we failed to recognize the input string or if we failed to
generate the uevent itself.

With the error codes properly propagated back to userspace, we are
able to react in userspace accordingly by not assuming and awaiting
a uevent that is not delivered.

Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-12 19:47:06 +01:00
Ard Biesheuvel
7290d58095 module: use relative references for __ksymtab entries
An ordinary arm64 defconfig build has ~64 KB worth of __ksymtab entries,
each consisting of two 64-bit fields containing absolute references, to
the symbol itself and to a char array containing its name, respectively.

When we build the same configuration with KASLR enabled, we end up with an
additional ~192 KB of relocations in the .init section, i.e., one 24 byte
entry for each absolute reference, which all need to be processed at boot
time.

Given how the struct kernel_symbol that describes each entry is completely
local to module.c (except for the references emitted by EXPORT_SYMBOL()
itself), we can easily modify it to contain two 32-bit relative references
instead.  This reduces the size of the __ksymtab section by 50% for all
64-bit architectures, and gets rid of the runtime relocations entirely for
architectures implementing KASLR, either via standard PIE linking (arm64)
or using custom host tools (x86).

Note that the binary search involving __ksymtab contents relies on each
section being sorted by symbol name.  This is implemented based on the
input section names, not the names in the ksymtab entries, so this patch
does not interfere with that.

Given that the use of place-relative relocations requires support both in
the toolchain and in the module loader, we cannot enable this feature for
all architectures.  So make it dependent on whether
CONFIG_HAVE_ARCH_PREL32_RELOCATIONS is defined.

Link: http://lkml.kernel.org/r/20180704083651.24360-4-ard.biesheuvel@linaro.org
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morris <james.morris@microsoft.com>
Cc: James Morris <jmorris@namei.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Linus Torvalds
d190775206 Modules updates for v4.19
Summary of modules changes for the 4.19 merge window:
 
 - Fix modules kallsyms for livepatch. Livepatch modules can have
   SHN_UNDEF symbols in their module symbol tables for later symbol
   resolution, but kallsyms shouldn't be returning these symbols
 
 - Some code cleanups and minor reshuffling in load_module() were done to
   log the module name when module signature verification fails
 
 Signed-off-by: Jessica Yu <jeyu@kernel.org>
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Merge tag 'modules-for-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

Pull modules updates from Jessica Yu:
 "Summary of modules changes for the 4.19 merge window:

   - Fix modules kallsyms for livepatch. Livepatch modules can have
     SHN_UNDEF symbols in their module symbol tables for later symbol
     resolution, but kallsyms shouldn't be returning these symbols

   - Some code cleanups and minor reshuffling in load_module() were done
     to log the module name when module signature verification fails"

* tag 'modules-for-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  kernel/module: Use kmemdup to replace kmalloc+memcpy
  ARM: module: fix modsign build error
  modsign: log module name in the event of an error
  module: replace VMLINUX_SYMBOL_STR() with __stringify() or string literal
  module: print sensible error code
  module: setup load info before module_sig_check()
  module: make it clear when we're handling the module copy in info->hdr
  module: exclude SHN_UNDEF symbols from kallsyms api
2018-08-17 10:51:22 -07:00
zhong jiang
9be936f4b3 kernel/module: Use kmemdup to replace kmalloc+memcpy
we prefer to the kmemdup rather than kmalloc+memcpy. so just
replace them.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2018-08-02 18:03:17 +02:00
Mimi Zohar
c77b8cdf74 module: replace the existing LSM hook in init_module
Both the init_module and finit_module syscalls call either directly
or indirectly the security_kernel_read_file LSM hook.  This patch
replaces the direct call in init_module with a call to the new
security_kernel_load_data hook and makes the corresponding changes
in SELinux, LoadPin, and IMA.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-07-16 12:31:57 -07:00
Jessica Yu
f314dfea16 modsign: log module name in the event of an error
Now that we have the load_info struct all initialized (including
info->name, which contains the name of the module) before
module_sig_check(), make the load_info struct and hence module name
available to mod_verify_sig() so that we can log the module name in the
event of an error.

Signed-off-by: Jessica Yu <jeyu@kernel.org>
2018-07-02 11:36:17 +02:00
Masahiro Yamada
996302c5e8 module: replace VMLINUX_SYMBOL_STR() with __stringify() or string literal
With the special case handling for Blackfin and Metag was removed by
commit 94e58e0ac312 ("export.h: remove code for prefixing symbols with
underscore"), VMLINUX_SYMBOL_STR() is now equivalent to __stringify().

Replace the remaining usages to prepare for the entire removal of
VMLINUX_SYMBOL_STR().

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2018-06-25 11:18:29 +02:00
Jason A. Donenfeld
62267e0ecc module: print sensible error code
Printing "err 0" to the user in the warning message is not particularly
useful, especially when this gets transformed into a -ENOENT for the
remainder of the call chain.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2018-06-25 10:37:08 +02:00
Jessica Yu
5fdc7db644 module: setup load info before module_sig_check()
We want to be able to log the module name in early error messages, such as
when module signature verification fails.  Previously, the module name is
set in layout_and_allocate(), meaning that any error messages that happen
before (such as those in module_sig_check()) won't be logged with a module
name, which isn't terribly helpful.

In order to do this, reshuffle the order in load_module() and set up
load info earlier so that we can log the module name along with these
error messages. This requires splitting rewrite_section_headers() out of
setup_load_info().

While we're at it, clean up and split up the operations done in
layout_and_allocate(), setup_load_info(), and rewrite_section_headers()
more cleanly so these functions only perform what their names suggest.

Signed-off-by: Jessica Yu <jeyu@kernel.org>
2018-06-22 14:00:01 +02:00
Jessica Yu
81a0abd9f2 module: make it clear when we're handling the module copy in info->hdr
In load_module(), it's not always clear whether we're handling the
temporary module copy in info->hdr (which is freed at the end of
load_module()) or if we're handling the module already allocated and
copied to it's final place. Adding an info->mod field and using it
whenever we're handling the temporary copy makes that explicitly clear.

Signed-off-by: Jessica Yu <jeyu@kernel.org>
2018-06-22 13:59:29 +02:00
Jessica Yu
9f2d1e68cf module: exclude SHN_UNDEF symbols from kallsyms api
Livepatch modules are special in that we preserve their entire symbol
tables in order to be able to apply relocations after module load. The
unwanted side effect of this is that undefined (SHN_UNDEF) symbols of
livepatch modules are accessible via the kallsyms api and this can
confuse symbol resolution in livepatch (klp_find_object_symbol()) and
cause subtle bugs in livepatch.

Have the module kallsyms api skip over SHN_UNDEF symbols. These symbols
are usually not available for normal modules anyway as we cut down their
symbol tables to just the core (non-undefined) symbols, so this should
really just affect livepatch modules. Note that this patch doesn't
affect the display of undefined symbols in /proc/kallsyms.

Reported-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2018-06-18 10:04:03 +02:00
Linus Torvalds
de7f01c22a Modules updates for v4.18
Summary of modules changes for the 4.18 merge window:
 
 - Minor code cleanup and also allow sig_enforce param to be shown in
   sysfs with CONFIG_MODULE_SIG_FORCE
 
 Signed-off-by: Jessica Yu <jeyu@kernel.org>
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Merge tag 'modules-for-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

Pull module updates from Jessica Yu:
 "Minor code cleanup and also allow sig_enforce param to be shown in
  sysfs with CONFIG_MODULE_SIG_FORCE"

* tag 'modules-for-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  module: Allow to always show the status of modsign
  module: Do not access sig_enforce directly
2018-06-16 07:36:39 +09:00
Linus Torvalds
2857676045 - Introduce arithmetic overflow test helper functions (Rasmus)
- Use overflow helpers in 2-factor allocators (Kees, Rasmus)
 - Introduce overflow test module (Rasmus, Kees)
 - Introduce saturating size helper functions (Matthew, Kees)
 - Treewide use of struct_size() for allocators (Kees)
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Merge tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull overflow updates from Kees Cook:
 "This adds the new overflow checking helpers and adds them to the
  2-factor argument allocators. And this adds the saturating size
  helpers and does a treewide replacement for the struct_size() usage.
  Additionally this adds the overflow testing modules to make sure
  everything works.

  I'm still working on the treewide replacements for allocators with
  "simple" multiplied arguments:

     *alloc(a * b, ...) -> *alloc_array(a, b, ...)

  and

     *zalloc(a * b, ...) -> *calloc(a, b, ...)

  as well as the more complex cases, but that's separable from this
  portion of the series. I expect to have the rest sent before -rc1
  closes; there are a lot of messy cases to clean up.

  Summary:

   - Introduce arithmetic overflow test helper functions (Rasmus)

   - Use overflow helpers in 2-factor allocators (Kees, Rasmus)

   - Introduce overflow test module (Rasmus, Kees)

   - Introduce saturating size helper functions (Matthew, Kees)

   - Treewide use of struct_size() for allocators (Kees)"

* tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  treewide: Use struct_size() for devm_kmalloc() and friends
  treewide: Use struct_size() for vmalloc()-family
  treewide: Use struct_size() for kmalloc()-family
  device: Use overflow helpers for devm_kmalloc()
  mm: Use overflow helpers in kvmalloc()
  mm: Use overflow helpers in kmalloc_array*()
  test_overflow: Add memory allocation overflow tests
  overflow.h: Add allocation size calculation helpers
  test_overflow: Report test failures
  test_overflow: macrofy some more, do more tests for free
  lib: add runtime test of check_*_overflow functions
  compiler.h: enable builtin overflow checkers and add fallback code
2018-06-06 17:27:14 -07:00
Kees Cook
acafe7e302 treewide: Use struct_size() for kmalloc()-family
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);

This patch makes the changes for kmalloc()-family (and kvmalloc()-family)
uses. It was done via automatic conversion with manual review for the
"CHECKME" non-standard cases noted below, using the following Coccinelle
script:

// pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
//                      sizeof *pkey_cache->table, GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// Same pattern, but can't trivially locate the trailing element name,
// or variable name.
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
expression SOMETHING, COUNT, ELEMENT;
@@

- alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP)
+ alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-06 11:15:43 -07:00
Jeffrey Hugo
ae646f0b9c init: fix false positives in W+X checking
load_module() creates W+X mappings via __vmalloc_node_range() (from
layout_and_allocate()->move_module()->module_alloc()) by using
PAGE_KERNEL_EXEC.  These mappings are later cleaned up via
"call_rcu_sched(&freeinit->rcu, do_free_init)" from do_init_module().

This is a problem because call_rcu_sched() queues work, which can be run
after debug_checkwx() is run, resulting in a race condition.  If hit,
the race results in a nasty splat about insecure W+X mappings, which
results in a poor user experience as these are not the mappings that
debug_checkwx() is intended to catch.

This issue is observed on multiple arm64 platforms, and has been
artificially triggered on an x86 platform.

Address the race by flushing the queued work before running the
arch-defined mark_rodata_ro() which then calls debug_checkwx().

Link: http://lkml.kernel.org/r/1525103946-29526-1-git-send-email-jhugo@codeaurora.org
Fixes: e1a58320a38d ("x86/mm: Warn on W^X mappings")
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reported-by: Timur Tabi <timur@codeaurora.org>
Reported-by: Jan Glauber <jan.glauber@caviumnetworks.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-11 17:28:45 -07:00
Thomas Richter
be71eda538 module: Fix display of wrong module .text address
Reading file /proc/modules shows the correct address:
[root@s35lp76 ~]# cat /proc/modules | egrep '^qeth_l2'
qeth_l2 94208 1 - Live 0x000003ff80401000

and reading file /sys/module/qeth_l2/sections/.text
[root@s35lp76 ~]# cat /sys/module/qeth_l2/sections/.text
0x0000000018ea8363
displays a random address.

This breaks the perf tool which uses this address on s390
to calculate start of .text section in memory.

Fix this by printing the correct (unhashed) address.

Thanks to Jessica Yu for helping on this.

Fixes: ef0010a30935 ("vsprintf: don't use 'restricted_pointer()' when not restricting")
Cc: <stable@vger.kernel.org> # v4.15+
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2018-04-18 22:59:46 +02:00
Jia Zhang
c554b89868 module: Allow to always show the status of modsign
The sig_enforce parameter could be always shown to reflect the current
status of signature enforcement. For the case of
CONFIG_MODULE_SIG_FORCE=y, this modification doesn't do anything, since
sig_enforce can only be enabled, and not disabled, even via the kernel
cmdline.

Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>
[jeyu: reworded commit message to provide clarification]
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2018-04-16 23:49:33 +02:00
Jia Zhang
2c8fd268f4 module: Do not access sig_enforce directly
Call is_module_sig_enforced() instead.

Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2018-04-16 23:46:03 +02:00
Linus Torvalds
f5a8eb632b arch: remove obsolete architecture ports
This removes the entire architecture code for blackfin, cris, frv, m32r,
 metag, mn10300, score, and tile, including the associated device drivers.
 
 I have been working with the (former) maintainers for each one to ensure
 that my interpretation was right and the code is definitely unused in
 mainline kernels. Many had fond memories of working on the respective
 ports to start with and getting them included in upstream, but also saw
 no point in keeping the port alive without any users.
 
 In the end, it seems that while the eight architectures are extremely
 different, they all suffered the same fate: There was one company
 in charge of an SoC line, a CPU microarchitecture and a software
 ecosystem, which was more costly than licensing newer off-the-shelf
 CPU cores from a third party (typically ARM, MIPS, or RISC-V). It seems
 that all the SoC product lines are still around, but have not used the
 custom CPU architectures for several years at this point. In contrast,
 CPU instruction sets that remain popular and have actively maintained
 kernel ports tend to all be used across multiple licensees.
 
 The removal came out of a discussion that is now documented at
 https://lwn.net/Articles/748074/. Unlike the original plans, I'm not
 marking any ports as deprecated but remove them all at once after I made
 sure that they are all unused. Some architectures (notably tile, mn10300,
 and blackfin) are still being shipped in products with old kernels,
 but those products will never be updated to newer kernel releases.
 
 After this series, we still have a few architectures without mainline
 gcc support:
 
 - unicore32 and hexagon both have very outdated gcc releases, but the
   maintainers promised to work on providing something newer. At least
   in case of hexagon, this will only be llvm, not gcc.
 
 - openrisc, risc-v and nds32 are still in the process of finishing their
   support or getting it added to mainline gcc in the first place.
   They all have patched gcc-7.3 ports that work to some degree, but
   complete upstream support won't happen before gcc-8.1. Csky posted
   their first kernel patch set last week, their situation will be similar.
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Merge tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

Pul removal of obsolete architecture ports from Arnd Bergmann:
 "This removes the entire architecture code for blackfin, cris, frv,
  m32r, metag, mn10300, score, and tile, including the associated device
  drivers.

  I have been working with the (former) maintainers for each one to
  ensure that my interpretation was right and the code is definitely
  unused in mainline kernels. Many had fond memories of working on the
  respective ports to start with and getting them included in upstream,
  but also saw no point in keeping the port alive without any users.

  In the end, it seems that while the eight architectures are extremely
  different, they all suffered the same fate: There was one company in
  charge of an SoC line, a CPU microarchitecture and a software
  ecosystem, which was more costly than licensing newer off-the-shelf
  CPU cores from a third party (typically ARM, MIPS, or RISC-V). It
  seems that all the SoC product lines are still around, but have not
  used the custom CPU architectures for several years at this point. In
  contrast, CPU instruction sets that remain popular and have actively
  maintained kernel ports tend to all be used across multiple licensees.

  [ See the new nds32 port merged in the previous commit for the next
    generation of "one company in charge of an SoC line, a CPU
    microarchitecture and a software ecosystem"   - Linus ]

  The removal came out of a discussion that is now documented at
  https://lwn.net/Articles/748074/. Unlike the original plans, I'm not
  marking any ports as deprecated but remove them all at once after I
  made sure that they are all unused. Some architectures (notably tile,
  mn10300, and blackfin) are still being shipped in products with old
  kernels, but those products will never be updated to newer kernel
  releases.

  After this series, we still have a few architectures without mainline
  gcc support:

   - unicore32 and hexagon both have very outdated gcc releases, but the
     maintainers promised to work on providing something newer. At least
     in case of hexagon, this will only be llvm, not gcc.

   - openrisc, risc-v and nds32 are still in the process of finishing
     their support or getting it added to mainline gcc in the first
     place. They all have patched gcc-7.3 ports that work to some
     degree, but complete upstream support won't happen before gcc-8.1.
     Csky posted their first kernel patch set last week, their situation
     will be similar

  [ Palmer Dabbelt points out that RISC-V support is in mainline gcc
    since gcc-7, although gcc-7.3.0 is the recommended minimum  - Linus ]"

This really says it all:

 2498 files changed, 95 insertions(+), 467668 deletions(-)

* tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (74 commits)
  MAINTAINERS: UNICORE32: Change email account
  staging: iio: remove iio-trig-bfin-timer driver
  tty: hvc: remove tile driver
  tty: remove bfin_jtag_comm and hvc_bfin_jtag drivers
  serial: remove tile uart driver
  serial: remove m32r_sio driver
  serial: remove blackfin drivers
  serial: remove cris/etrax uart drivers
  usb: Remove Blackfin references in USB support
  usb: isp1362: remove blackfin arch glue
  usb: musb: remove blackfin port
  usb: host: remove tilegx platform glue
  pwm: remove pwm-bfin driver
  i2c: remove bfin-twi driver
  spi: remove blackfin related host drivers
  watchdog: remove bfin_wdt driver
  can: remove bfin_can driver
  mmc: remove bfin_sdh driver
  input: misc: remove blackfin rotary driver
  input: keyboard: remove bf54x driver
  ...
2018-04-02 20:20:12 -07:00
Arnd Bergmann
1a8429132e mm: remove blackfin MPU support
The CONFIG_MPU option was only defined on blackfin, and that architecture
is now being removed, so the respective code can be simplified.

A lot of other microcontrollers have an MPU, but I suspect that if we
want to bring that support back, we'd do it differently anyway.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-16 10:56:10 +01:00