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commit c79a39dc8d060b9e64e8b0fa9d245d44befeefbe upstream.
On a board running ntpd and gpsd, I'm seeing a consistent use-after-free
in sys_exit() from gpsd when rebooting:
pps pps1: removed
------------[ cut here ]------------
kobject: '(null)' (00000000db4bec24): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 2 PID: 440 at lib/kobject.c:734 kobject_put+0x120/0x150
CPU: 2 UID: 299 PID: 440 Comm: gpsd Not tainted 6.11.0-rc6-00308-gb31c44928842 #1
Hardware name: Raspberry Pi 4 Model B Rev 1.1 (DT)
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : kobject_put+0x120/0x150
lr : kobject_put+0x120/0x150
sp : ffffffc0803d3ae0
x29: ffffffc0803d3ae0 x28: ffffff8042dc9738 x27: 0000000000000001
x26: 0000000000000000 x25: ffffff8042dc9040 x24: ffffff8042dc9440
x23: ffffff80402a4620 x22: ffffff8042ef4bd0 x21: ffffff80405cb600
x20: 000000000008001b x19: ffffff8040b3b6e0 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 696e6920746f6e20
x14: 7369203a29343263 x13: 205d303434542020 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
kobject_put+0x120/0x150
cdev_put+0x20/0x3c
__fput+0x2c4/0x2d8
____fput+0x1c/0x38
task_work_run+0x70/0xfc
do_exit+0x2a0/0x924
do_group_exit+0x34/0x90
get_signal+0x7fc/0x8c0
do_signal+0x128/0x13b4
do_notify_resume+0xdc/0x160
el0_svc+0xd4/0xf8
el0t_64_sync_handler+0x140/0x14c
el0t_64_sync+0x190/0x194
---[ end trace 0000000000000000 ]---
...followed by more symptoms of corruption, with similar stacks:
refcount_t: underflow; use-after-free.
kernel BUG at lib/list_debug.c:62!
Kernel panic - not syncing: Oops - BUG: Fatal exception
This happens because pps_device_destruct() frees the pps_device with the
embedded cdev immediately after calling cdev_del(), but, as the comment
above cdev_del() notes, fops for previously opened cdevs are still
callable even after cdev_del() returns. I think this bug has always
been there: I can't explain why it suddenly started happening every time
I reboot this particular board.
In commit d953e0e837e6 ("pps: Fix a use-after free bug when
unregistering a source."), George Spelvin suggested removing the
embedded cdev. That seems like the simplest way to fix this, so I've
implemented his suggestion, using __register_chrdev() with pps_idr
becoming the source of truth for which minor corresponds to which
device.
But now that pps_idr defines userspace visibility instead of cdev_add(),
we need to be sure the pps->dev refcount can't reach zero while
userspace can still find it again. So, the idr_remove() call moves to
pps_unregister_cdev(), and pps_idr now holds a reference to pps->dev.
pps_core: source serial1 got cdev (251:1)
<...>
pps pps1: removed
pps_core: unregistering pps1
pps_core: deallocating pps1
Fixes: d953e0e837e6 ("pps: Fix a use-after free bug when unregistering a source.")
Cc: stable@vger.kernel.org
Signed-off-by: Calvin Owens <calvin@wbinvd.org>
Reviewed-by: Michal Schmidt <mschmidt@redhat.com>
Link: https://lore.kernel.org/r/a17975fd5ae99385791929e563f72564edbcf28f.1731383727.git.calvin@wbinvd.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 70e6b7d9ae3c63df90a7bba7700e8d5c300c3c60 upstream.
Leaving the PIT interrupt running can cause noticeable steal time for
virtual guests. The VMM generally has a timer which toggles the IRQ input
to the PIC and I/O APIC, which takes CPU time away from the guest. Even
on real hardware, running the counter may use power needlessly (albeit
not much).
Make sure it's turned off if it isn't going to be used.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhkelley@outlook.com>
Link: https://lore.kernel.org/all/20240802135555.564941-1-dwmw2@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 3029ad91335353a70feb42acd24d580d70ab258b upstream.
Move PCI Vendor and Device ID of ASIX AX99100 PCIe to Multi I/O
Controller to pci_ids.h for its serial and parallel port driver
support in subsequent patches.
Signed-off-by: Jiaqing Zhao <jiaqing.zhao@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/r/20230724083933.3173513-3-jiaqing.zhao@linux.intel.com
[Moeko: Drop changes in drivers/net/can/sja1000/ems_pci.c]
Signed-off-by: Tomita Moeko <tomitamoeko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 482ad2a4ace2740ca0ff1cbc8f3c7f862f3ab507 ]
dev->nd_net can change, readers should either
use rcu_read_lock() or RTNL.
We currently use a generic helper, dev_net() with
no debugging support. We probably have many hidden bugs.
Add dev_net_rcu() helper for callers using rcu_read_lock()
protection.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250205155120.1676781-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: dd205fcc33d9 ("ipv4: use RCU protection in rt_is_expired()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit ba69e0750b0362870294adab09339a0c39c3beaf upstream.
UEFI 2.11 introduced EFI_MEMORY_HOT_PLUGGABLE to annotate system memory
regions that are 'cold plugged' at boot, i.e., hot pluggable memory that
is available from early boot, and described as system RAM by the
firmware.
Existing loaders and EFI applications running in the boot context will
happily use this memory for allocating data structures that cannot be
freed or moved at runtime, and this prevents the memory from being
unplugged. Going forward, the new EFI_MEMORY_HOT_PLUGGABLE attribute
should be tested, and memory annotated as such should be avoided for
such allocations.
In the EFI stub, there are a couple of occurrences where, instead of the
high-level AllocatePages() UEFI boot service, a low-level code sequence
is used that traverses the EFI memory map and carves out the requested
number of pages from a free region. This is needed, e.g., for allocating
as low as possible, or for allocating pages at random.
While AllocatePages() should presumably avoid special purpose memory and
cold plugged regions, this manual approach needs to incorporate this
logic itself, in order to prevent the kernel itself from ending up in a
hot unpluggable region, preventing it from being unplugged.
So add the EFI_MEMORY_HOTPLUGGABLE macro definition, and check for it
where appropriate.
Cc: stable@vger.kernel.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1e7381f3617d14b3c11da80ff5f8a93ab14cfc46 upstream.
Explicitly verify the target vCPU is fully online _prior_ to clamping the
index in kvm_get_vcpu(). If the index is "bad", the nospec clamping will
generate '0', i.e. KVM will return vCPU0 instead of NULL.
In practice, the bug is unlikely to cause problems, as it will only come
into play if userspace or the guest is buggy or misbehaving, e.g. KVM may
send interrupts to vCPU0 instead of dropping them on the floor.
However, returning vCPU0 when it shouldn't exist per online_vcpus is
problematic now that KVM uses an xarray for the vCPUs array, as KVM needs
to insert into the xarray before publishing the vCPU to userspace (see
commit c5b077549136 ("KVM: Convert the kvm->vcpus array to a xarray")),
i.e. before vCPU creation is guaranteed to succeed.
As a result, incorrectly providing access to vCPU0 will trigger a
use-after-free if vCPU0 is dereferenced and kvm_vm_ioctl_create_vcpu()
bails out of vCPU creation due to an error and frees vCPU0. Commit
afb2acb2e3a3 ("KVM: Fix vcpu_array[0] races") papered over that issue, but
in doing so introduced an unsolvable teardown conundrum. Preventing
accesses to vCPU0 before it's fully online will allow reverting commit
afb2acb2e3a3, without re-introducing the vcpu_array[0] UAF race.
Fixes: 1d487e9bf8ba ("KVM: fix spectrev1 gadgets")
Cc: stable@vger.kernel.org
Cc: Will Deacon <will@kernel.org>
Cc: Michal Luczaj <mhal@rbox.co>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241009150455.1057573-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit a769154c7cac037914ba375ae88aae55b2c853e0 ]
- The HCD address_device callback now accepts a user-defined timeout value
in milliseconds, providing better control over command execution times.
- The default timeout value for the address_device command has been set
to 5000 ms, aligning with the USB 3.2 specification. However, this
timeout can be adjusted as needed.
- The xhci_setup_device function has been updated to accept the timeout
value, allowing it to specify the maximum wait time for the command
operation to complete.
- The hub driver has also been updated to accommodate the newly added
timeout parameter during the SET_ADDRESS request.
Signed-off-by: Hardik Gajjar <hgajjar@de.adit-jv.com>
Reviewed-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20231027152029.104363-1-hgajjar@de.adit-jv.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 1e0a19912adb ("usb: xhci: Fix NULL pointer dereference on certain command aborts")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit e61e6c415ba9ff2b32bb6780ce1b17d1d76238f1 ]
The overflow_work is using system wq to do overflow checks and updates
for PHC device timecounter, which might be overhelmed by other tasks.
But there is dedicated kthread in PTP subsystem designed for such
things. This patch changes the work queue to proper align with PTP
subsystem and to avoid overloading system work queue.
The adjfine() function acts the same way as overflow check worker,
we can postpone ptp aux worker till the next overflow period after
adjfine() was called.
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Vadim Fedorenko <vadfed@meta.com>
Acked-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20250107104812.380225-1-vadfed@meta.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit a145c848d69f9c6f32008d8319edaa133360dd74 ]
dereference_symbol_descriptor() needs to obtain the module pointer
belonging to pointer in order to resolve that pointer.
The returned mod pointer is obtained under RCU-sched/ preempt_disable()
guarantees and needs to be used within this section to ensure that the
module is not removed in the meantime.
Extend the preempt_disable() section to also cover
dereference_module_function_descriptor().
Fixes: 04b8eb7a4ccd9 ("symbol lookup: introduce dereference_symbol_descriptor()")
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Helge Deller <deller@gmx.de>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20250108090457.512198-2-bigeasy@linutronix.de
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 130eac4170859fb368681e00d390f20f44bbf27b upstream.
A recent patch caused an unused-function warning in builds with
CONFIG_PM disabled, after the function became marked 'static':
drivers/usb/host/xhci-pci.c:91:13: error: 'xhci_msix_sync_irqs' defined but not used [-Werror=unused-function]
91 | static void xhci_msix_sync_irqs(struct xhci_hcd *xhci)
| ^~~~~~~~~~~~~~~~~~~
This could be solved by adding another #ifdef, but as there is
a trend towards removing CONFIG_PM checks in favor of helper
macros, do the same conversion here and use pm_ptr() to get
either a function pointer or NULL but avoid the warning.
As the hidden functions reference some other symbols, make
sure those are visible at compile time, at the minimal cost of
a few extra bytes for 'struct usb_device'.
Fixes: 9abe15d55dcc ("xhci: Move xhci MSI sync function to to xhci-pci")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20230328131114.1296430-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit f90877dd7fb5085dd9abd6399daf63dd2969fc90 ]
When using !CONFIG_SECCOMP with CONFIG_GENERIC_ENTRY, the
randconfig bots found the following snag:
kernel/entry/common.c: In function 'syscall_trace_enter':
>> kernel/entry/common.c:52:23: error: implicit declaration
of function '__secure_computing' [-Wimplicit-function-declaration]
52 | ret = __secure_computing(NULL);
| ^~~~~~~~~~~~~~~~~~
Since generic entry calls __secure_computing() unconditionally,
fix this by moving the stub out of the ifdef clause for
CONFIG_HAVE_ARCH_SECCOMP_FILTER so it's always available.
Link: https://lore.kernel.org/oe-kbuild-all/202501061240.Fzk9qiFZ-lkp@intel.com/
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20250108-seccomp-stub-2-v2-1-74523d49420f@linaro.org
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 86e6ca55b83c575ab0f2e105cf08f98e58d3d7af upstream.
blkcg_unpin_online() walks up the blkcg hierarchy putting the online pin. To
walk up, it uses blkcg_parent(blkcg) but it was calling that after
blkcg_destroy_blkgs(blkcg) which could free the blkcg, leading to the
following UAF:
==================================================================
BUG: KASAN: slab-use-after-free in blkcg_unpin_online+0x15a/0x270
Read of size 8 at addr ffff8881057678c0 by task kworker/9:1/117
CPU: 9 UID: 0 PID: 117 Comm: kworker/9:1 Not tainted 6.13.0-rc1-work-00182-gb8f52214c61a-dirty #48
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 02/02/2022
Workqueue: cgwb_release cgwb_release_workfn
Call Trace:
<TASK>
dump_stack_lvl+0x27/0x80
print_report+0x151/0x710
kasan_report+0xc0/0x100
blkcg_unpin_online+0x15a/0x270
cgwb_release_workfn+0x194/0x480
process_scheduled_works+0x71b/0xe20
worker_thread+0x82a/0xbd0
kthread+0x242/0x2c0
ret_from_fork+0x33/0x70
ret_from_fork_asm+0x1a/0x30
</TASK>
...
Freed by task 1944:
kasan_save_track+0x2b/0x70
kasan_save_free_info+0x3c/0x50
__kasan_slab_free+0x33/0x50
kfree+0x10c/0x330
css_free_rwork_fn+0xe6/0xb30
process_scheduled_works+0x71b/0xe20
worker_thread+0x82a/0xbd0
kthread+0x242/0x2c0
ret_from_fork+0x33/0x70
ret_from_fork_asm+0x1a/0x30
Note that the UAF is not easy to trigger as the free path is indirected
behind a couple RCU grace periods and a work item execution. I could only
trigger it with artifical msleep() injected in blkcg_unpin_online().
Fix it by reading the parent pointer before destroying the blkcg's blkg's.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Abagail ren <renzezhongucas@gmail.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Fixes: 4308a434e5e0 ("blkcg: don't offline parent blkcg first")
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 2f8dea1692eef2b7ba6a256246ed82c365fdc686 upstream.
Consider a scenario where a CPU transitions from CPUHP_ONLINE to halfway
through a CPU hotunplug down to CPUHP_HRTIMERS_PREPARE, and then back to
CPUHP_ONLINE:
Since hrtimers_prepare_cpu() does not run, cpu_base.hres_active remains set
to 1 throughout. However, during a CPU unplug operation, the tick and the
clockevents are shut down at CPUHP_AP_TICK_DYING. On return to the online
state, for instance CFS incorrectly assumes that the hrtick is already
active, and the chance of the clockevent device to transition to oneshot
mode is also lost forever for the CPU, unless it goes back to a lower state
than CPUHP_HRTIMERS_PREPARE once.
This round-trip reveals another issue; cpu_base.online is not set to 1
after the transition, which appears as a WARN_ON_ONCE in enqueue_hrtimer().
Aside of that, the bulk of the per CPU state is not reset either, which
means there are dangling pointers in the worst case.
Address this by adding a corresponding startup() callback, which resets the
stale per CPU state and sets the online flag.
[ tglx: Make the new callback unconditionally available, remove the online
modification in the prepare() callback and clear the remaining
state in the starting callback instead of the prepare callback ]
Fixes: 5c0930ccaad5 ("hrtimers: Push pending hrtimers away from outgoing CPU earlier")
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20241220134421.3809834-1-koichiro.den@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.poll()
[ Upstream commit cacd9ae4bf801ff4125d8961bb9a3ba955e51680 ]
As the comment above waitqueue_active() explains, it can only be used
if both waker and waiter have mb()'s that pair with each other. However
__pollwait() is broken in this respect.
This is not pipe-specific, but let's look at pipe_poll() for example:
poll_wait(...); // -> __pollwait() -> add_wait_queue()
LOAD(pipe->head);
LOAD(pipe->head);
In theory these LOAD()'s can leak into the critical section inside
add_wait_queue() and can happen before list_add(entry, wq_head), in this
case pipe_poll() can race with wakeup_pipe_readers/writers which do
smp_mb();
if (waitqueue_active(wq_head))
wake_up_interruptible(wq_head);
There are more __pollwait()-like functions (grep init_poll_funcptr), and
it seems that at least ep_ptable_queue_proc() has the same problem, so the
patch adds smp_mb() into poll_wait().
Link: https://lore.kernel.org/all/20250102163320.GA17691@redhat.com/
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20250107162717.GA18922@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b8dfed636fc6239396c3a2ae5f812505906cf215 ]
Add additional flow steering priorities in the RDMA namespace.
This allows adding flow counters to count filtered RDMA traffic and then
continue processing in the regular RDMA steering flow.
Signed-off-by: Aharon Landau <aharonl@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Stable-dep-of: c08d3e62b2e7 ("net/mlx5: Fix RDMA TX steering prio")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 449f4ec9892ebc2f37a7eae6d97db2cf7c65e09a ]
The update_bdev argument is always set to true, so remove it. Also
rename the function to the slighly less verbose set_capacity_and_notify,
as propagating the disk size to the block device isn't really
revalidation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: 74363ec674cb ("zram: fix uninitialized ZRAM not releasing backing device")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit f91a5b8089389eb408501af2762f168c3aaa7b79 ]
Blamed commit forgot MSG_PEEK case, allowing a crash [1] as found
by syzbot.
Rework vlan_get_protocol_dgram() to not touch skb at all,
so that it can be used from many cpus on the same skb.
Add a const qualifier to skb argument.
[1]
skbuff: skb_under_panic: text:ffffffff8a8ccd05 len:29 put:14 head:ffff88807fc8e400 data:ffff88807fc8e3f4 tail:0x11 end:0x140 dev:<NULL>
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:206 !
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 5892 Comm: syz-executor883 Not tainted 6.13.0-rc4-syzkaller-00054-gd6ef8b40d075 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:skb_panic net/core/skbuff.c:206 [inline]
RIP: 0010:skb_under_panic+0x14b/0x150 net/core/skbuff.c:216
Code: 0b 8d 48 c7 c6 86 d5 25 8e 48 8b 54 24 08 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 41 54 41 57 41 56 e8 5a 69 79 f7 48 83 c4 20 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3
RSP: 0018:ffffc900038d7638 EFLAGS: 00010282
RAX: 0000000000000087 RBX: dffffc0000000000 RCX: 609ffd18ea660600
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffff88802483c8d0 R08: ffffffff817f0a8c R09: 1ffff9200071ae60
R10: dffffc0000000000 R11: fffff5200071ae61 R12: 0000000000000140
R13: ffff88807fc8e400 R14: ffff88807fc8e3f4 R15: 0000000000000011
FS: 00007fbac5e006c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbac5e00d58 CR3: 000000001238e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
skb_push+0xe5/0x100 net/core/skbuff.c:2636
vlan_get_protocol_dgram+0x165/0x290 net/packet/af_packet.c:585
packet_recvmsg+0x948/0x1ef0 net/packet/af_packet.c:3552
sock_recvmsg_nosec net/socket.c:1033 [inline]
sock_recvmsg+0x22f/0x280 net/socket.c:1055
____sys_recvmsg+0x1c6/0x480 net/socket.c:2803
___sys_recvmsg net/socket.c:2845 [inline]
do_recvmmsg+0x426/0xab0 net/socket.c:2940
__sys_recvmmsg net/socket.c:3014 [inline]
__do_sys_recvmmsg net/socket.c:3037 [inline]
__se_sys_recvmmsg net/socket.c:3030 [inline]
__x64_sys_recvmmsg+0x199/0x250 net/socket.c:3030
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Fixes: 79eecf631c14 ("af_packet: Handle outgoing VLAN packets without hardware offloading")
Reported-by: syzbot+74f70bb1cb968bf09e4f@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6772c485.050a0220.2f3838.04c5.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Chengen Du <chengen.du@canonical.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20241230161004.2681892-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit e05feab22fd7dabcd6d272c4e2401ec1acdfdb9b ]
Different core device types such as PFs and VFs shouldn't be affiliated
together since they have different capabilities, fix that by enforcing
type check before doing the affiliation.
Fixes: 32f69e4be269 ("{net, IB}/mlx5: Manage port association for multiport RoCE")
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Patrisious Haddad <phaddad@nvidia.com>
Link: https://patch.msgid.link/88699500f690dff1c1852c1ddb71f8a1cc8b956e.1733233480.git.leonro@nvidia.com
Reviewed-by: Mateusz Polchlopek <mateusz.polchlopek@intel.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 3b1e58aa832ed537289be6a51a2015309688a90c ]
Subsequent patch implements helper API which has mlx5_core_dev
as const pointer, make its caller API too const *.
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Bodong Wang <bodong@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Stable-dep-of: e05feab22fd7 ("RDMA/mlx5: Enforce same type port association for multiport RoCE")
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
commit 452f4b31e3f70a52b97890888eeb9eaa9a87139a upstream.
The name member of the struct trace_event_call is assigned with
generated string literals; declare them pointer to read-only.
Reported by clang:
security/landlock/syscalls.c:179:1: warning: initializing 'char *' with an expression of type 'const char[34]' discards qualifiers [-Wincompatible-pointer-types-discards-qualifiers]
179 | SYSCALL_DEFINE3(landlock_create_ruleset,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
180 | const struct landlock_ruleset_attr __user *const, attr,
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
181 | const size_t, size, const __u32, flags)
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/syscalls.h:226:36: note: expanded from macro 'SYSCALL_DEFINE3'
226 | #define SYSCALL_DEFINE3(name, ...) SYSCALL_DEFINEx(3, _##name, __VA_ARGS__)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/syscalls.h:234:2: note: expanded from macro 'SYSCALL_DEFINEx'
234 | SYSCALL_METADATA(sname, x, __VA_ARGS__) \
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/syscalls.h:184:2: note: expanded from macro 'SYSCALL_METADATA'
184 | SYSCALL_TRACE_ENTER_EVENT(sname); \
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/syscalls.h:151:30: note: expanded from macro 'SYSCALL_TRACE_ENTER_EVENT'
151 | .name = "sys_enter"#sname, \
| ^~~~~~~~~~~~~~~~~
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mickaël Salaün <mic@digikod.net>
Cc: Günther Noack <gnoack@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/20241125105028.42807-1-cgoettsche@seltendoof.de
Fixes: b77e38aa240c3 ("tracing: add event trace infrastructure")
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
[ Upstream commit f1260ff15a71b8fc122b2c9abd8a7abffb6e0168 ]
Like skb_realloc_headroom(), new helper increases headroom of specified skb.
Unlike skb_realloc_headroom(), it does not allocate a new skb if possible;
copies skb->sk on new skb when as needed and frees original skb in case
of failures.
This helps to simplify ip[6]_finish_output2() and a few other similar cases.
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit f1260ff15a71b8fc122b2c9abd8a7abffb6e0168)
Signed-off-by: Harshvardhan Jha <harshvardhan.j.jha@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 30c2de0a267c04046d89e678cc0067a9cfb455df ]
Fix the following clang compiler warning that is reported if the kernel is
built with W=1:
./include/linux/vmstat.h:518:36: error: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Werror,-Wenum-enum-conversion]
518 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
| ~~~~~~~~~~~ ^ ~~~
Link: https://lkml.kernel.org/r/20241212213126.1269116-1-bvanassche@acm.org
Fixes: 9d7ea9a297e6 ("mm/vmstat: add helpers to get vmstat item names for each enum type")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
commit 900bbaae67e980945dec74d36f8afe0de7556d5a upstream.
Now, the epoll only use wake_up() interface to wake up task.
However, sometimes, there are epoll users which want to use
the synchronous wakeup flag to hint the scheduler, such as
Android binder driver.
So add a wake_up_sync() define, and use the wake_up_sync()
when the sync is true in ep_poll_callback().
Co-developed-by: Jing Xia <jing.xia@unisoc.com>
Signed-off-by: Jing Xia <jing.xia@unisoc.com>
Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Link: https://lore.kernel.org/r/20240426080548.8203-1-xuewen.yan@unisoc.com
Tested-by: Brian Geffon <bgeffon@google.com>
Reviewed-by: Brian Geffon <bgeffon@google.com>
Reported-by: Benoit Lize <lizeb@google.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 07a756a49f4b4290b49ea46e089cbe6f79ff8d26 upstream.
If the KVP (or VSS) daemon starts before the VMBus channel's ringbuffer is
fully initialized, we can hit the panic below:
hv_utils: Registering HyperV Utility Driver
hv_vmbus: registering driver hv_utils
...
BUG: kernel NULL pointer dereference, address: 0000000000000000
CPU: 44 UID: 0 PID: 2552 Comm: hv_kvp_daemon Tainted: G E 6.11.0-rc3+ #1
RIP: 0010:hv_pkt_iter_first+0x12/0xd0
Call Trace:
...
vmbus_recvpacket
hv_kvp_onchannelcallback
vmbus_on_event
tasklet_action_common
tasklet_action
handle_softirqs
irq_exit_rcu
sysvec_hyperv_stimer0
</IRQ>
<TASK>
asm_sysvec_hyperv_stimer0
...
kvp_register_done
hvt_op_read
vfs_read
ksys_read
__x64_sys_read
This can happen because the KVP/VSS channel callback can be invoked
even before the channel is fully opened:
1) as soon as hv_kvp_init() -> hvutil_transport_init() creates
/dev/vmbus/hv_kvp, the kvp daemon can open the device file immediately and
register itself to the driver by writing a message KVP_OP_REGISTER1 to the
file (which is handled by kvp_on_msg() ->kvp_handle_handshake()) and
reading the file for the driver's response, which is handled by
hvt_op_read(), which calls hvt->on_read(), i.e. kvp_register_done().
2) the problem with kvp_register_done() is that it can cause the
channel callback to be called even before the channel is fully opened,
and when the channel callback is starting to run, util_probe()->
vmbus_open() may have not initialized the ringbuffer yet, so the
callback can hit the panic of NULL pointer dereference.
To reproduce the panic consistently, we can add a "ssleep(10)" for KVP in
__vmbus_open(), just before the first hv_ringbuffer_init(), and then we
unload and reload the driver hv_utils, and run the daemon manually within
the 10 seconds.
Fix the panic by reordering the steps in util_probe() so the char dev
entry used by the KVP or VSS daemon is not created until after
vmbus_open() has completed. This reordering prevents the race condition
from happening.
Reported-by: Dexuan Cui <decui@microsoft.com>
Fixes: e0fa3e5e7df6 ("Drivers: hv: utils: fix a race on userspace daemons registration")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20241106154247.2271-3-mhklinux@outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20241106154247.2271-3-mhklinux@outlook.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 349f0086ba8b2a169877d21ff15a4d9da3a60054 upstream.
In 32-bit x86 builds CONFIG_STATIC_CALL_INLINE isn't set, leading to
static_call_initialized not being available.
Define it as "0" in that case.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 0ef8047b737d ("x86/static-call: provide a way to do very early static-call updates")
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 0ef8047b737d7480a5d4c46d956e97c190f13050 upstream.
Add static_call_update_early() for updating static-call targets in
very early boot.
This will be needed for support of Xen guest type specific hypercall
functions.
This is part of XSA-466 / CVE-2024-53241.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Co-developed-by: Peter Zijlstra <peterz@infradead.org>
Co-developed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
[ Upstream commit 7738a7ab9d12c5371ed97114ee2132d4512e9fd5 ]
Add a quirk similar to eeprom_93xx46 to add an extra clock cycle before
reading data from the EEPROM.
The 93Cx6 family of EEPROMs output a "dummy 0 bit" between the writing
of the op-code/address from the host to the EEPROM and the reading of
the actual data from the EEPROM.
More info can be found on page 6 of the AT93C46 datasheet (linked below).
Similar notes are found in other 93xx6 datasheets.
In summary the read operation for a 93Cx6 EEPROM is:
Write to EEPROM: 110[A5-A0] (9 bits)
Read from EEPROM: 0[D15-D0] (17 bits)
Where:
110 is the start bit and READ OpCode
[A5-A0] is the address to read from
0 is a "dummy bit" preceding the actual data
[D15-D0] is the actual data.
Looking at the READ timing diagrams in the 93Cx6 datasheets the dummy
bit should be clocked out on the last address bit clock cycle meaning it
should be discarded naturally.
However, depending on the hardware configuration sometimes this dummy
bit is not discarded. This is the case with Exar PCI UARTs which require
an extra clock cycle between sending the address and reading the data.
Datasheet: https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-5193-SEEPROM-AT93C46D-Datasheet.pdf
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Parker Newman <pnewman@connecttech.com>
Link: https://lore.kernel.org/r/0f23973efefccd2544705a0480b4ad4c2353e407.1727880931.git.pnewman@connecttech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 4ca7cd938725a4050dcd62ae9472e931d603118d ]
There is NULL pointer issue observed if from Process A where hid device
being added which results in adding a led_cdev addition and later a
another call to access of led_cdev attribute from Process B can result
in NULL pointer issue.
Use mutex led_cdev->led_access to protect access to led->cdev and its
attribute inside brightness_show() and max_brightness_show() and also
update the comment for mutex that it should be used to protect the led
class device fields.
Process A Process B
kthread+0x114
worker_thread+0x244
process_scheduled_works+0x248
uhid_device_add_worker+0x24
hid_add_device+0x120
device_add+0x268
bus_probe_device+0x94
device_initial_probe+0x14
__device_attach+0xfc
bus_for_each_drv+0x10c
__device_attach_driver+0x14c
driver_probe_device+0x3c
__driver_probe_device+0xa0
really_probe+0x190
hid_device_probe+0x130
ps_probe+0x990
ps_led_register+0x94
devm_led_classdev_register_ext+0x58
led_classdev_register_ext+0x1f8
device_create_with_groups+0x48
device_create_groups_vargs+0xc8
device_add+0x244
kobject_uevent+0x14
kobject_uevent_env[jt]+0x224
mutex_unlock[jt]+0xc4
__mutex_unlock_slowpath+0xd4
wake_up_q+0x70
try_to_wake_up[jt]+0x48c
preempt_schedule_common+0x28
__schedule+0x628
__switch_to+0x174
el0t_64_sync+0x1a8/0x1ac
el0t_64_sync_handler+0x68/0xbc
el0_svc+0x38/0x68
do_el0_svc+0x1c/0x28
el0_svc_common+0x80/0xe0
invoke_syscall+0x58/0x114
__arm64_sys_read+0x1c/0x2c
ksys_read+0x78/0xe8
vfs_read+0x1e0/0x2c8
kernfs_fop_read_iter+0x68/0x1b4
seq_read_iter+0x158/0x4ec
kernfs_seq_show+0x44/0x54
sysfs_kf_seq_show+0xb4/0x130
dev_attr_show+0x38/0x74
brightness_show+0x20/0x4c
dualshock4_led_get_brightness+0xc/0x74
[ 3313.874295][ T4013] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000060
[ 3313.874301][ T4013] Mem abort info:
[ 3313.874303][ T4013] ESR = 0x0000000096000006
[ 3313.874305][ T4013] EC = 0x25: DABT (current EL), IL = 32 bits
[ 3313.874307][ T4013] SET = 0, FnV = 0
[ 3313.874309][ T4013] EA = 0, S1PTW = 0
[ 3313.874311][ T4013] FSC = 0x06: level 2 translation fault
[ 3313.874313][ T4013] Data abort info:
[ 3313.874314][ T4013] ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000
[ 3313.874316][ T4013] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 3313.874318][ T4013] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 3313.874320][ T4013] user pgtable: 4k pages, 39-bit VAs, pgdp=00000008f2b0a000
..
[ 3313.874332][ T4013] Dumping ftrace buffer:
[ 3313.874334][ T4013] (ftrace buffer empty)
..
..
[ dd3313.874639][ T4013] CPU: 6 PID: 4013 Comm: InputReader
[ 3313.874648][ T4013] pc : dualshock4_led_get_brightness+0xc/0x74
[ 3313.874653][ T4013] lr : led_update_brightness+0x38/0x60
[ 3313.874656][ T4013] sp : ffffffc0b910bbd0
..
..
[ 3313.874685][ T4013] Call trace:
[ 3313.874687][ T4013] dualshock4_led_get_brightness+0xc/0x74
[ 3313.874690][ T4013] brightness_show+0x20/0x4c
[ 3313.874692][ T4013] dev_attr_show+0x38/0x74
[ 3313.874696][ T4013] sysfs_kf_seq_show+0xb4/0x130
[ 3313.874700][ T4013] kernfs_seq_show+0x44/0x54
[ 3313.874703][ T4013] seq_read_iter+0x158/0x4ec
[ 3313.874705][ T4013] kernfs_fop_read_iter+0x68/0x1b4
[ 3313.874708][ T4013] vfs_read+0x1e0/0x2c8
[ 3313.874711][ T4013] ksys_read+0x78/0xe8
[ 3313.874714][ T4013] __arm64_sys_read+0x1c/0x2c
[ 3313.874718][ T4013] invoke_syscall+0x58/0x114
[ 3313.874721][ T4013] el0_svc_common+0x80/0xe0
[ 3313.874724][ T4013] do_el0_svc+0x1c/0x28
[ 3313.874727][ T4013] el0_svc+0x38/0x68
[ 3313.874730][ T4013] el0t_64_sync_handler+0x68/0xbc
[ 3313.874732][ T4013] el0t_64_sync+0x1a8/0x1ac
Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com>
Reviewed-by: Anish Kumar <yesanishhere@gmail.com>
Link: https://lore.kernel.org/r/20241103160527.82487-1-quic_mojha@quicinc.com
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 2f552fa280590e61bd3dbe66a7b54b99caa642a4 ]
Extend the address status bit to 4 and introduce the
I3C_ADDR_SLOT_EXT_DESIRED macro to indicate that a device prefers a
specific address. This is generally set by the 'assigned-address' in the
device tree source (dts) file.
┌────┬─────────────┬───┬─────────┬───┐
│S/Sr│ 7'h7E RnW=0 │ACK│ ENTDAA │ T ├────┐
└────┴─────────────┴───┴─────────┴───┘ │
┌─────────────────────────────────────────┘
│ ┌──┬─────────────┬───┬─────────────────┬────────────────┬───┬─────────┐
└─►│Sr│7'h7E RnW=1 │ACK│48bit UID BCR DCR│Assign 7bit Addr│PAR│ ACK/NACK│
└──┴─────────────┴───┴─────────────────┴────────────────┴───┴─────────┘
Some master controllers (such as HCI) need to prepare the entire above
transaction before sending it out to the I3C bus. This means that a 7-bit
dynamic address needs to be allocated before knowing the target device's
UID information.
However, some I3C targets may request specific addresses (called as
"init_dyn_addr"), which is typically specified by the DT-'s
assigned-address property. Lower addresses having higher IBI priority. If
it is available, i3c_bus_get_free_addr() preferably return a free address
that is not in the list of desired addresses (called as "init_dyn_addr").
This allows the device with the "init_dyn_addr" to switch to its
"init_dyn_addr" when it hot-joins the I3C bus. Otherwise, if the
"init_dyn_addr" is already in use by another I3C device, the target device
will not be able to switch to its desired address.
If the previous step fails, fallback returning one of the remaining
unassigned address, regardless of its state in the desired list.
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20241021-i3c_dts_assign-v8-2-4098b8bde01e@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Stable-dep-of: 851bd21cdb55 ("i3c: master: Fix dynamic address leak when 'assigned-address' is present")
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 16aed0a6520ba01b7d22c32e193fc1ec674f92d4 ]
Replace the hardcoded value 2, which indicates 2 bits for I3C address
status, with the predefined macro I3C_ADDR_SLOT_STATUS_BITS.
Improve maintainability and extensibility of the code.
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20241021-i3c_dts_assign-v8-1-4098b8bde01e@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Stable-dep-of: 851bd21cdb55 ("i3c: master: Fix dynamic address leak when 'assigned-address' is present")
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
commit bc73b4186736341ab5cd2c199da82db6e1134e13 upstream.
A bug was found in the find_closest() (find_closest_descending() is also
affected after some testing), where for certain values with small
progressions, the rounding (done by averaging 2 values) causes an
incorrect index to be returned. The rounding issues occur for
progressions of 1, 2 and 3. It goes away when the progression/interval
between two values is 4 or larger.
It's particularly bad for progressions of 1. For example if there's an
array of 'a = { 1, 2, 3 }', using 'find_closest(2, a ...)' would return 0
(the index of '1'), rather than returning 1 (the index of '2'). This
means that for exact values (with a progression of 1), find_closest() will
misbehave and return the index of the value smaller than the one we're
searching for.
For progressions of 2 and 3, the exact values are obtained correctly; but
values aren't approximated correctly (as one would expect). Starting with
progressions of 4, all seems to be good (one gets what one would expect).
While one could argue that 'find_closest()' should not be used for arrays
with progressions of 1 (i.e. '{1, 2, 3, ...}', the macro should still
behave correctly.
The bug was found while testing the 'drivers/iio/adc/ad7606.c',
specifically the oversampling feature.
For reference, the oversampling values are listed as:
static const unsigned int ad7606_oversampling_avail[7] = {
1, 2, 4, 8, 16, 32, 64,
};
When doing:
1. $ echo 1 > /sys/bus/iio/devices/iio\:device0/oversampling_ratio
$ cat /sys/bus/iio/devices/iio\:device0/oversampling_ratio
1 # this is fine
2. $ echo 2 > /sys/bus/iio/devices/iio\:device0/oversampling_ratio
$ cat /sys/bus/iio/devices/iio\:device0/oversampling_ratio
1 # this is wrong; 2 should be returned here
3. $ echo 3 > /sys/bus/iio/devices/iio\:device0/oversampling_ratio
$ cat /sys/bus/iio/devices/iio\:device0/oversampling_ratio
2 # this is fine
4. $ echo 4 > /sys/bus/iio/devices/iio\:device0/oversampling_ratio
$ cat /sys/bus/iio/devices/iio\:device0/oversampling_ratio
4 # this is fine
And from here-on, the values are as correct (one gets what one would
expect.)
While writing a kunit test for this bug, a peculiar issue was found for the
array in the 'drivers/hwmon/ina2xx.c' & 'drivers/iio/adc/ina2xx-adc.c'
drivers. While running the kunit test (for 'ina226_avg_tab' from these
drivers):
* idx = find_closest([-1 to 2], ina226_avg_tab, ARRAY_SIZE(ina226_avg_tab));
This returns idx == 0, so value.
* idx = find_closest(3, ina226_avg_tab, ARRAY_SIZE(ina226_avg_tab));
This returns idx == 0, value 1; and now one could argue whether 3 is
closer to 4 or to 1. This quirk only appears for value '3' in this
array, but it seems to be a another rounding issue.
* And from 4 onwards the 'find_closest'() works fine (one gets what one
would expect).
This change reworks the find_closest() macros to also check the difference
between the left and right elements when 'x'. If the distance to the right
is smaller (than the distance to the left), the index is incremented by 1.
This also makes redundant the need for using the DIV_ROUND_CLOSEST() macro.
In order to accommodate for any mix of negative + positive values, the
internal variables '__fc_x', '__fc_mid_x', '__fc_left' & '__fc_right' are
forced to 'long' type. This also addresses any potential bugs/issues with
'x' being of an unsigned type. In those situations any comparison between
signed & unsigned would be promoted to a comparison between 2 unsigned
numbers; this is especially annoying when '__fc_left' & '__fc_right'
underflow.
The find_closest_descending() macro was also reworked and duplicated from
the find_closest(), and it is b |