commit 0a46781c89 upstream.
When 'mcf_edma' is allocated, some space is allocated for a
flexible array at the end of the struct. 'chans' item are allocated, that is
to say 'pdata->dma_channels'.
Then, this number of item is stored in 'mcf_edma->n_chans'.
A few lines later, if 'mcf_edma->n_chans' is 0, then a default value of 64
is set.
This ends to no space allocated by devm_kzalloc() because chans was 0, but
64 items are read and/or written in some not allocated memory.
Change the logic to define a default value before allocating the memory.
Fixes: e7a3ff92ea ("dmaengine: fsl-edma: add ColdFire mcf5441x edma support")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/f55d914407c900828f6fad3ea5fa791a5f17b9a4.1685172449.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 01f4fd2708 upstream.
BUG_ON(!vlan_info) is triggered in unregister_vlan_dev() with
following testcase:
# ip netns add ns1
# ip netns exec ns1 ip link add bond0 type bond mode 0
# ip netns exec ns1 ip link add bond_slave_1 type veth peer veth2
# ip netns exec ns1 ip link set bond_slave_1 master bond0
# ip netns exec ns1 ip link add link bond_slave_1 name vlan10 type vlan id 10 protocol 802.1ad
# ip netns exec ns1 ip link add link bond0 name bond0_vlan10 type vlan id 10 protocol 802.1ad
# ip netns exec ns1 ip link set bond_slave_1 nomaster
# ip netns del ns1
The logical analysis of the problem is as follows:
1. create ETH_P_8021AD protocol vlan10 for bond_slave_1:
register_vlan_dev()
vlan_vid_add()
vlan_info_alloc()
__vlan_vid_add() // add [ETH_P_8021AD, 10] vid to bond_slave_1
2. create ETH_P_8021AD protocol bond0_vlan10 for bond0:
register_vlan_dev()
vlan_vid_add()
__vlan_vid_add()
vlan_add_rx_filter_info()
if (!vlan_hw_filter_capable(dev, proto)) // condition established because bond0 without NETIF_F_HW_VLAN_STAG_FILTER
return 0;
if (netif_device_present(dev))
return dev->netdev_ops->ndo_vlan_rx_add_vid(dev, proto, vid); // will be never called
// The slaves of bond0 will not refer to the [ETH_P_8021AD, 10] vid.
3. detach bond_slave_1 from bond0:
__bond_release_one()
vlan_vids_del_by_dev()
list_for_each_entry(vid_info, &vlan_info->vid_list, list)
vlan_vid_del(dev, vid_info->proto, vid_info->vid);
// bond_slave_1 [ETH_P_8021AD, 10] vid will be deleted.
// bond_slave_1->vlan_info will be assigned NULL.
4. delete vlan10 during delete ns1:
default_device_exit_batch()
dev->rtnl_link_ops->dellink() // unregister_vlan_dev() for vlan10
vlan_info = rtnl_dereference(real_dev->vlan_info); // real_dev of vlan10 is bond_slave_1
BUG_ON(!vlan_info); // bond_slave_1->vlan_info is NULL now, bug is triggered!!!
Add S-VLAN tag related features support to bond driver. So the bond driver
will always propagate the VLAN info to its slaves.
Fixes: 8ad227ff89 ("net: vlan: add 802.1ad support")
Suggested-by: Ido Schimmel <idosch@idosch.org>
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20230802114320.4156068-1-william.xuanziyang@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1696ec8654 upstream.
When booting a kernel with CONFIG_MISDN_DSP=y and CONFIG_CFI_CLANG=y,
there is a failure when dsp_cmx_send() is called indirectly from
call_timer_fn():
[ 0.371412] CFI failure at call_timer_fn+0x2f/0x150 (target: dsp_cmx_send+0x0/0x530; expected type: 0x92ada1e9)
The function pointer prototype that call_timer_fn() expects is
void (*fn)(struct timer_list *)
whereas dsp_cmx_send() has a parameter type of 'void *', which causes
the control flow integrity checks to fail because the parameter types do
not match.
Change dsp_cmx_send()'s parameter type to be 'struct timer_list' to
match the expected prototype. The argument is unused anyways, so this
has no functional change, aside from avoiding the CFI failure.
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202308020936.58787e6c-oliver.sang@intel.com
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Fixes: e313ac12eb ("mISDN: Convert timers to use timer_setup()")
Link: https://lore.kernel.org/r/20230802-fix-dsp_cmx_send-cfi-failure-v1-1-2f2e79b0178d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d5ad9aae13 upstream.
Commit 3bcbc20942 ("selftests/rseq: Play nice with binaries statically
linked against glibc 2.35+") which is now in Linus' tree introduced uses
of __weak but did nothing to ensure that a definition is provided for it
resulting in build failures for the rseq tests:
rseq.c:41:1: error: unknown type name '__weak'
__weak ptrdiff_t __rseq_offset;
^
rseq.c:41:17: error: expected ';' after top level declarator
__weak ptrdiff_t __rseq_offset;
^
;
rseq.c:42:1: error: unknown type name '__weak'
__weak unsigned int __rseq_size;
^
rseq.c:43:1: error: unknown type name '__weak'
__weak unsigned int __rseq_flags;
Fix this by using the definition from tools/include compiler.h.
Fixes: 3bcbc20942 ("selftests/rseq: Play nice with binaries statically linked against glibc 2.35+")
Signed-off-by: Mark Brown <broonie@kernel.org>
Message-Id: <20230804-kselftest-rseq-build-v1-1-015830b66aa9@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1b8b1aa90c upstream.
Yingcong has noticed that on the 5-level paging machine, VDSO and VVAR
VMAs are placed above the 47-bit border:
8000001a9000-8000001ad000 r--p 00000000 00:00 0 [vvar]
8000001ad000-8000001af000 r-xp 00000000 00:00 0 [vdso]
This might confuse users who are not aware of 5-level paging and expect
all userspace addresses to be under the 47-bit border.
So far problem has only been triggered with ASLR disabled, although it
may also occur with ASLR enabled if the layout is randomized in a just
right way.
The problem happens due to custom placement for the VMAs in the VDSO
code: vdso_addr() tries to place them above the stack and checks the
result against TASK_SIZE_MAX, which is wrong. TASK_SIZE_MAX is set to
the 56-bit border on 5-level paging machines. Use DEFAULT_MAP_WINDOW
instead.
Fixes: b569bab78d ("x86/mm: Prepare to expose larger address space to userspace")
Reported-by: Yingcong Wu <yingcong.wu@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20230803151609.22141-1-kirill.shutemov%40linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3ddaa6a274 upstream.
If dwc3 is runtime suspended we defer processing the event buffer
until resume, by setting the pending_events flag. Set this flag before
triggering resume to avoid race with the runtime resume callback.
While handling the pending events, in addition to checking the event
buffer we also need to process it. Handle this by explicitly calling
dwc3_thread_interrupt(). Also balance the runtime pm get() operation
that triggered this processing.
Cc: stable@vger.kernel.org
Fixes: fc8bb91bc8 ("usb: dwc3: implement runtime PM")
Signed-off-by: Elson Roy Serrao <quic_eserrao@quicinc.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Link: https://lore.kernel.org/r/20230801192658.19275-1-quic_eserrao@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a6ff6e7a9d upstream.
Syzbot got KMSAN to complain about access to an uninitialized value in
the alauda subdriver of usb-storage:
BUG: KMSAN: uninit-value in alauda_transport+0x462/0x57f0
drivers/usb/storage/alauda.c:1137
CPU: 0 PID: 12279 Comm: usb-storage Not tainted 5.3.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x191/0x1f0 lib/dump_stack.c:113
kmsan_report+0x13a/0x2b0 mm/kmsan/kmsan_report.c:108
__msan_warning+0x73/0xe0 mm/kmsan/kmsan_instr.c:250
alauda_check_media+0x344/0x3310 drivers/usb/storage/alauda.c:460
The problem is that alauda_check_media() doesn't verify that its USB
transfer succeeded before trying to use the received data. What
should happen if the transfer fails isn't entirely clear, but a
reasonably conservative approach is to pretend that no media is
present.
A similar problem exists in a usb_stor_dbg() call in
alauda_get_media_status(). In this case, when an error occurs the
call is redundant, because usb_stor_ctrl_transfer() already will print
a debugging message.
Finally, unrelated to the uninitialized memory access, is the fact
that alauda_check_media() performs DMA to a buffer on the stack.
Fortunately usb-storage provides a general purpose DMA-able buffer for
uses like this. We'll use it instead.
Reported-and-tested-by: syzbot+e7d46eb426883fb97efd@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/0000000000007d25ff059457342d@google.com/T/
Suggested-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Fixes: e80b0fade0 ("[PATCH] USB Storage: add alauda support")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/693d5d5e-f09b-42d0-8ed9-1f96cd30bcce@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f8654743a0 upstream.
During unmount process of nilfs2, nothing holds nilfs_root structure after
nilfs2 detaches its writer in nilfs_detach_log_writer(). Previously,
nilfs_evict_inode() could cause use-after-free read for nilfs_root if
inodes are left in "garbage_list" and released by nilfs_dispose_list at
the end of nilfs_detach_log_writer(), and this bug was fixed by commit
9b5a04ac3a ("nilfs2: fix use-after-free bug of nilfs_root in
nilfs_evict_inode()").
However, it turned out that there is another possibility of UAF in the
call path where mark_inode_dirty_sync() is called from iput():
nilfs_detach_log_writer()
nilfs_dispose_list()
iput()
mark_inode_dirty_sync()
__mark_inode_dirty()
nilfs_dirty_inode()
__nilfs_mark_inode_dirty()
nilfs_load_inode_block() --> causes UAF of nilfs_root struct
This can happen after commit 0ae45f63d4 ("vfs: add support for a
lazytime mount option"), which changed iput() to call
mark_inode_dirty_sync() on its final reference if i_state has I_DIRTY_TIME
flag and i_nlink is non-zero.
This issue appears after commit 28a65b49eb ("nilfs2: do not write dirty
data after degenerating to read-only") when using the syzbot reproducer,
but the issue has potentially existed before.
Fix this issue by adding a "purging flag" to the nilfs structure, setting
that flag while disposing the "garbage_list" and checking it in
__nilfs_mark_inode_dirty().
Unlike commit 9b5a04ac3a ("nilfs2: fix use-after-free bug of nilfs_root
in nilfs_evict_inode()"), this patch does not rely on ns_writer to
determine whether to skip operations, so as not to break recovery on
mount. The nilfs_salvage_orphan_logs routine dirties the buffer of
salvaged data before attaching the log writer, so changing
__nilfs_mark_inode_dirty() to skip the operation when ns_writer is NULL
will cause recovery write to fail. The purpose of using the cleanup-only
flag is to allow for narrowing of such conditions.
Link: https://lkml.kernel.org/r/20230728191318.33047-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+74db8b3087f293d3a13a@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/000000000000b4e906060113fd63@google.com
Fixes: 0ae45f63d4 ("vfs: add support for a lazytime mount option")
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org> # 4.0+
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 048c796beb upstream.
The upcoming (and nearly finalized):
https://datatracker.ietf.org/doc/draft-collink-6man-pio-pflag/
will update the IPv6 RA to include a new flag in the PIO field,
which will serve as a hint to perform DHCPv6-PD.
As we don't want DHCPv6 related logic inside the kernel, this piece of
information needs to be exposed to userspace. The simplest option is to
simply expose the entire PIO through the already existing mechanism.
Even without this new flag, the already existing PIO R (router address)
flag (from RFC6275) cannot AFAICT be handled entirely in kernel,
and provides useful information that should be exposed to userspace
(the router's global address, for use by Mobile IPv6).
Also cc'ing stable@ for inclusion in LTS, as while technically this is
not quite a bugfix, and instead more of a feature, it is absolutely
trivial and the alternative is manually cherrypicking into all Android
Common Kernel trees - and I know Greg will ask for it to be sent in via
LTS instead...
Cc: Jen Linkova <furry@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: YOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@linux-ipv6.org>
Cc: stable@vger.kernel.org
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20230807102533.1147559-1-maze@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f601e8f37c upstream.
This reverts commit e1f82a0dcf as it's
already starting to cause build warnings in linux-next for things that
are "obviously correct".
It's up to driver authors do "do the right thing" here with this
function, and if they don't want to call it as the last line of a
function, that's up to them, otherwise code that looks like:
ret = dev_err_probe(..., ret, ...);
does look really "odd".
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Krzysztof Kozlowski <krzk@kernel.org>
Fixes: e1f82a0dcf ("driver core: Annotate dev_err_probe() with __must_check")
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 074b3aad30 upstream.
There are two literal blocks there. Fix the markups, in order
to produce the right html output and solve those warnings:
./drivers/base/core.c:4218: WARNING: Unexpected indentation.
./drivers/base/core.c:4222: WARNING: Definition list ends without a blank line; unexpected unindent.
./drivers/base/core.c:4223: WARNING: Block quote ends without a blank line; unexpected unindent.
Fixes: a787e5400a ("driver core: add device probe log helper")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 5c8b3b8a18 ]
Add usb alias for bootloader searching the controller in correct order.
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Stable-dep-of: ee70b908f7 ("ARM: dts: nxp/imx6sll: fix wrong property name in usbphy node")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5da1b522cf ]
In imx6sll.dtsi, the ssi node name is different with other
platforms (imx6qdl, imx6sl, imx6sx), but the
sound/soc/fsl/fsl-asoc-card.c machine driver needs to check
ssi node name for audmux configuration, then different ssi
node name causes issue on imx6sll platform.
So we change ssi node name to make all platforms have same
name.
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Stable-dep-of: ee70b908f7 ("ARM: dts: nxp/imx6sll: fix wrong property name in usbphy node")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 470a5c77ea ]
ceph open-codes this around some other activity and the rationale
for it isn't clear. There is no need to delay free_anon_bdev until
the end of kill_sb.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Stable-dep-of: e7e607bd00 ("ceph: defer stopping mdsc delayed_work")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3a3430affc ]
Add some visibility of tasks that are waiting for caps to the "caps"
debugfs file. Display the tgid of the waiting task, inode number, and
the caps the task needs and wants.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Stable-dep-of: e7e607bd00 ("ceph: defer stopping mdsc delayed_work")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8527beb120 ]
The decision whether to enable a wake irq during suspend can not be done
based on the runtime PM state directly as a driver may use wake irqs
without implementing runtime PM. Such drivers specifically leave the
state set to the default 'suspended' and the wake irq is thus never
enabled at suspend.
Add a new wake irq flag to track whether a dedicated wake irq has been
enabled at runtime suspend and therefore must not be enabled at system
suspend.
Note that pm_runtime_enabled() can not be used as runtime PM is always
disabled during late suspend.
Fixes: 69728051f5 ("PM / wakeirq: Fix unbalanced IRQ enable for wakeirq")
Cc: 4.16+ <stable@vger.kernel.org> # 4.16+
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 259714100d ]
When the dedicated wake IRQ is level trigger, and it uses the
device's low-power status as the wakeup source, that means if the
device is not in low-power state, the wake IRQ will be triggered
if enabled; For this case, need enable the wake IRQ after running
the device's ->runtime_suspend() which make it enter low-power state.
e.g.
Assume the wake IRQ is a low level trigger type, and the wakeup
signal comes from the low-power status of the device.
The wakeup signal is low level at running time (0), and becomes
high level when the device enters low-power state (runtime_suspend
(1) is called), a wakeup event at (2) make the device exit low-power
state, then the wakeup signal also becomes low level.
------------------
| ^ ^|
---------------- | | --------------
|<---(0)--->|<--(1)--| (3) (2) (4)
if enable the wake IRQ before running runtime_suspend during (0),
a wake IRQ will arise, it causes resume immediately;
it works if enable wake IRQ ( e.g. at (3) or (4)) after running
->runtime_suspend().
This patch introduces a new status WAKE_IRQ_DEDICATED_REVERSE to
optionally support enabling wake IRQ after running ->runtime_suspend().
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Stable-dep-of: 8527beb120 ("PM: sleep: wakeirq: fix wake irq arming")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3bcbc20942 ]
To allow running rseq and KVM's rseq selftests as statically linked
binaries, initialize the various "trampoline" pointers to point directly
at the expect glibc symbols, and skip the dlysm() lookups if the rseq
size is non-zero, i.e. the binary is statically linked *and* the libc
registered its own rseq.
Define weak versions of the symbols so as not to break linking against
libc versions that don't support rseq in any capacity.
The KVM selftests in particular are often statically linked so that they
can be run on targets with very limited runtime environments, i.e. test
machines.
Fixes: 233e667e1a ("selftests/rseq: Uplift rseq selftests for compatibility with glibc-2.35")
Cc: Aaron Lewis <aaronlewis@google.com>
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230721223352.2333911-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d1a997ba4c ]
When checking for libc rseq support in the library constructor, don't
only depend on the symbols presence, check that the registration was
completed.
This targets a scenario where the libc has rseq support but it is not
wired for the current architecture in 'bits/rseq.h', we want to fallback
to our internal registration mechanism.
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/r/20220614154830.1367382-4-mjeanson@efficios.com
Stable-dep-of: 3bcbc20942 ("selftests/rseq: Play nice with binaries statically linked against glibc 2.35+")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 7dae593cd2 upstream.
In a couple of situations like
name = kstrndup(buf, count, GFP_KERNEL);
if (!name)
return -ENOSPC;
the error is not actually "No space left on device", but "Out of memory".
It is semantically correct to return -ENOMEM in all failed kstrndup()
and kzalloc() cases in this driver, as it is not a problem with disk
space, but with kernel memory allocator failing allocation.
The semantically correct should be:
name = kstrndup(buf, count, GFP_KERNEL);
if (!name)
return -ENOMEM;
Cc: Dan Carpenter <error27@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Luis R. Rodriguez" <mcgrof@ruslug.rutgers.edu>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Brian Norris <briannorris@chromium.org>
Fixes: c92316bf8e ("test_firmware: add batched firmware tests")
Fixes: 0a8adf5847 ("test: add firmware_class loader test")
Fixes: 548193cba2 ("test_firmware: add support for firmware_request_platform")
Fixes: eb910947c8 ("test: firmware_class: add asynchronous request trigger")
Fixes: 061132d2b9 ("test_firmware: add test custom fallback trigger")
Fixes: 7feebfa487 ("test_firmware: add support for request_firmware_into_buf")
Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Message-ID: <20230606070808.9300-1-mirsad.todorovac@alu.unizg.hr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4acfe3dfde upstream.
Dan Carpenter spotted a race condition in a couple of situations like
these in the test_firmware driver:
static int test_dev_config_update_u8(const char *buf, size_t size, u8 *cfg)
{
u8 val;
int ret;
ret = kstrtou8(buf, 10, &val);
if (ret)
return ret;
mutex_lock(&test_fw_mutex);
*(u8 *)cfg = val;
mutex_unlock(&test_fw_mutex);
/* Always return full write size even if we didn't consume all */
return size;
}
static ssize_t config_num_requests_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int rc;
mutex_lock(&test_fw_mutex);
if (test_fw_config->reqs) {
pr_err("Must call release_all_firmware prior to changing config\n");
rc = -EINVAL;
mutex_unlock(&test_fw_mutex);
goto out;
}
mutex_unlock(&test_fw_mutex);
rc = test_dev_config_update_u8(buf, count,
&test_fw_config->num_requests);
out:
return rc;
}
static ssize_t config_read_fw_idx_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
return test_dev_config_update_u8(buf, count,
&test_fw_config->read_fw_idx);
}
The function test_dev_config_update_u8() is called from both the locked
and the unlocked context, function config_num_requests_store() and
config_read_fw_idx_store() which can both be called asynchronously as
they are driver's methods, while test_dev_config_update_u8() and siblings
change their argument pointed to by u8 *cfg or similar pointer.
To avoid deadlock on test_fw_mutex, the lock is dropped before calling
test_dev_config_update_u8() and re-acquired within test_dev_config_update_u8()
itself, but alas this creates a race condition.
Having two locks wouldn't assure a race-proof mutual exclusion.
This situation is best avoided by the introduction of a new, unlocked
function __test_dev_config_update_u8() which can be called from the locked
context and reducing test_dev_config_update_u8() to:
static int test_dev_config_update_u8(const char *buf, size_t size, u8 *cfg)
{
int ret;
mutex_lock(&test_fw_mutex);
ret = __test_dev_config_update_u8(buf, size, cfg);
mutex_unlock(&test_fw_mutex);
return ret;
}
doing the locking and calling the unlocked primitive, which enables both
locked and unlocked versions without duplication of code.
The similar approach was applied to all functions called from the locked
and the unlocked context, which safely mitigates both deadlocks and race
conditions in the driver.
__test_dev_config_update_bool(), __test_dev_config_update_u8() and
__test_dev_config_update_size_t() unlocked versions of the functions
were introduced to be called from the locked contexts as a workaround
without releasing the main driver's lock and thereof causing a race
condition.
The test_dev_config_update_bool(), test_dev_config_update_u8() and
test_dev_config_update_size_t() locked versions of the functions
are being called from driver methods without the unnecessary multiplying
of the locking and unlocking code for each method, and complicating
the code with saving of the return value across lock.
Fixes: 7feebfa487 ("test_firmware: add support for request_firmware_into_buf")
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Russ Weight <russell.h.weight@intel.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Tianfei Zhang <tianfei.zhang@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-kselftest@vger.kernel.org
Cc: stable@vger.kernel.org # v5.4
Suggested-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Link: https://lore.kernel.org/r/20230509084746.48259-1-mirsad.todorovac@alu.unizg.hr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c541dce86c upstream.
The reconfigure / remount code takes a lot of effort to protect
filesystem's reconfiguration code from racing writes on remounting
read-only. However during remounting read-only filesystem to read-write
mode userspace writes can start immediately once we clear SB_RDONLY
flag. This is inconvenient for example for ext4 because we need to do
some writes to the filesystem (such as preparation of quota files)
before we can take userspace writes so we are clearing SB_RDONLY flag
before we are fully ready to accept userpace writes and syzbot has found
a way to exploit this [1]. Also as far as I'm reading the code
the filesystem remount code was protected from racing writes in the
legacy mount path by the mount's MNT_READONLY flag so this is relatively
new problem. It is actually fairly easy to protect remount read-write
from racing writes using sb->s_readonly_remount flag so let's just do
that instead of having to workaround these races in the filesystem code.
[1] https://lore.kernel.org/all/00000000000006a0df05f6667499@google.com/T/
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <20230615113848.8439-1-jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
