Pull char/misc/IIO/whatever driver subsystem updates from Greg KH:
"Here is the 'big and hairy' char/misc/iio and other small driver
subsystem updates for 6.13-rc1.
Loads of things in here, and even a fun merge conflict!
- rust misc driver bindings and other rust changes to make misc
drivers actually possible.
I think this is the tipping point, expect to see way more rust
drivers going forward now that these bindings are present. Next
merge window hopefully we will have pci and platform drivers
working, which will fully enable almost all driver subsystems to
start accepting (or at least getting) rust drivers.
This is the end result of a lot of work from a lot of people,
congrats to all of them for getting this far, you've proved many of
us wrong in the best way possible, working code :)
- IIO driver updates, too many to list individually, that subsystem
keeps growing and growing...
- Interconnect driver updates
- nvmem driver updates
- pwm driver updates
- platform_driver::remove() fixups, loads of them
- counter driver updates
- misc driver updates (keba?)
- binder driver updates and fixes
- loads of other small char/misc/etc driver updates and additions,
full details in the shortlog.
All of these have been in linux-next for a while, with no other
reported issues other than that merge conflict"
* tag 'char-misc-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (401 commits)
mei: vsc: Fix typo "maintstepping" -> "mainstepping"
firmware: Switch back to struct platform_driver::remove()
misc: isl29020: Fix the wrong format specifier
scripts/tags.sh: Don't tag usages of DEFINE_MUTEX
fpga: Switch back to struct platform_driver::remove()
mei: vsc: Improve error logging in vsc_identify_silicon()
mei: vsc: Do not re-enable interrupt from vsc_tp_reset()
dt-bindings: spmi: qcom,x1e80100-spmi-pmic-arb: Add SAR2130P compatible
dt-bindings: spmi: spmi-mtk-pmif: Add compatible for MT8188
spmi: pmic-arb: fix return path in for_each_available_child_of_node()
iio: Move __private marking before struct element priv in struct iio_dev
docs: iio: ad7380: add adaq4370-4 and adaq4380-4
iio: adc: ad7380: add support for adaq4370-4 and adaq4380-4
iio: adc: ad7380: use local dev variable to shorten long lines
iio: adc: ad7380: fix oversampling formula
dt-bindings: iio: adc: ad7380: add adaq4370-4 and adaq4380-4 compatible parts
bus: mhi: host: pci_generic: Use pcim_iomap_region() to request and map MHI BAR
bus: mhi: host: Switch trace_mhi_gen_tre fields to native endian
misc: atmel-ssc: Use of_property_present() for non-boolean properties
misc: keba: Add hardware dependency
...
Currently, every list_lru has a per-node lock that protects adding,
deletion, isolation, and reparenting of all list_lru_one instances
belonging to this list_lru on this node. This lock contention is heavy
when multiple cgroups modify the same list_lru.
This lock can be split into per-cgroup scope to reduce contention.
To achieve this, we need a stable list_lru_one for every cgroup. This
commit adds a lock to each list_lru_one and introduced a helper function
lock_list_lru_of_memcg, making it possible to pin the list_lru of a memcg.
Then reworked the reparenting process.
Reparenting will switch the list_lru_one instances one by one. By locking
each instance and marking it dead using the nr_items counter, reparenting
ensures that all items in the corresponding cgroup (on-list or not,
because items have a stable cgroup, see below) will see the list_lru_one
switch synchronously.
Objcg reparent is also moved after list_lru reparent so items will have a
stable mem cgroup until all list_lru_one instances are drained.
The only caller that doesn't work the *_obj interfaces are direct calls to
list_lru_{add,del}. But it's only used by zswap and that's also based on
objcg, so it's fine.
This also changes the bahaviour of the isolation function when LRU_RETRY
or LRU_REMOVED_RETRY is returned, because now releasing the lock could
unblock reparenting and free the list_lru_one, isolation function will
have to return withoug re-lock the lru.
prepare() {
mkdir /tmp/test-fs
modprobe brd rd_nr=1 rd_size=33554432
mkfs.xfs -f /dev/ram0
mount -t xfs /dev/ram0 /tmp/test-fs
for i in $(seq 1 512); do
mkdir "/tmp/test-fs/$i"
for j in $(seq 1 10240); do
echo TEST-CONTENT > "/tmp/test-fs/$i/$j"
done &
done; wait
}
do_test() {
read_worker() {
sleep 1
tar -cv "$1" &>/dev/null
}
read_in_all() {
cd "/tmp/test-fs" && ls
for i in $(seq 1 512); do
(exec sh -c 'echo "$PPID"') > "/sys/fs/cgroup/benchmark/$i/cgroup.procs"
read_worker "$i" &
done; wait
}
for i in $(seq 1 512); do
mkdir -p "/sys/fs/cgroup/benchmark/$i"
done
echo +memory > /sys/fs/cgroup/benchmark/cgroup.subtree_control
echo 512M > /sys/fs/cgroup/benchmark/memory.max
echo 3 > /proc/sys/vm/drop_caches
time read_in_all
}
Above script simulates compression of small files in multiple cgroups
with memory pressure. Run prepare() then do_test for 6 times:
Before:
real 0m7.762s user 0m11.340s sys 3m11.224s
real 0m8.123s user 0m11.548s sys 3m2.549s
real 0m7.736s user 0m11.515s sys 3m11.171s
real 0m8.539s user 0m11.508s sys 3m7.618s
real 0m7.928s user 0m11.349s sys 3m13.063s
real 0m8.105s user 0m11.128s sys 3m14.313s
After this commit (about ~15% faster):
real 0m6.953s user 0m11.327s sys 2m42.912s
real 0m7.453s user 0m11.343s sys 2m51.942s
real 0m6.916s user 0m11.269s sys 2m43.957s
real 0m6.894s user 0m11.528s sys 2m45.346s
real 0m6.911s user 0m11.095s sys 2m43.168s
real 0m6.773s user 0m11.518s sys 2m40.774s
Link: https://lkml.kernel.org/r/20241104175257.60853-6-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Cc: Chengming Zhou <zhouchengming@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If a freeze notification is cleared with BC_CLEAR_FREEZE_NOTIFICATION
before calling binder_freeze_notification_done(), then it is detached
from its reference (e.g. ref->freeze) but the work remains queued in
proc->delivered_freeze. This leads to a memory leak when the process
exits as any pending entries in proc->delivered_freeze are not freed:
unreferenced object 0xffff38e8cfa36180 (size 64):
comm "binder-util", pid 655, jiffies 4294936641
hex dump (first 32 bytes):
b8 e9 9e c8 e8 38 ff ff b8 e9 9e c8 e8 38 ff ff .....8.......8..
0b 00 00 00 00 00 00 00 3c 1f 4b 00 00 00 00 00 ........<.K.....
backtrace (crc 95983b32):
[<000000000d0582cf>] kmemleak_alloc+0x34/0x40
[<000000009c99a513>] __kmalloc_cache_noprof+0x208/0x280
[<00000000313b1704>] binder_thread_write+0xdec/0x439c
[<000000000cbd33bb>] binder_ioctl+0x1b68/0x22cc
[<000000002bbedeeb>] __arm64_sys_ioctl+0x124/0x190
[<00000000b439adee>] invoke_syscall+0x6c/0x254
[<00000000173558fc>] el0_svc_common.constprop.0+0xac/0x230
[<0000000084f72311>] do_el0_svc+0x40/0x58
[<000000008b872457>] el0_svc+0x38/0x78
[<00000000ee778653>] el0t_64_sync_handler+0x120/0x12c
[<00000000a8ec61bf>] el0t_64_sync+0x190/0x194
This patch fixes the leak by ensuring that any pending entries in
proc->delivered_freeze are freed during binder_deferred_release().
Fixes: d579b04a52 ("binder: frozen notification")
Cc: stable@vger.kernel.org
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Todd Kjos <tkjos@google.com>
Link: https://lore.kernel.org/r/20240926233632.821189-8-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The BINDER_WORK_FROZEN_BINDER type is not handled in the binder_logs
entries and it shows up as "unknown work" when logged:
proc 649
context binder-test
thread 649: l 00 need_return 0 tr 0
ref 13: desc 1 node 8 s 1 w 0 d 0000000053c4c0c3
unknown work: type 10
This patch add the freeze work type and is now logged as such:
proc 637
context binder-test
thread 637: l 00 need_return 0 tr 0
ref 8: desc 1 node 3 s 1 w 0 d 00000000dc39e9c6
has frozen binder
Fixes: d579b04a52 ("binder: frozen notification")
Cc: stable@vger.kernel.org
Acked-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240926233632.821189-5-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a binder reference is cleaned up, any freeze work queued in the
associated process should also be removed. Otherwise, the reference is
freed while its ref->freeze.work is still queued in proc->work leading
to a use-after-free issue as shown by the following KASAN report:
==================================================================
BUG: KASAN: slab-use-after-free in binder_release_work+0x398/0x3d0
Read of size 8 at addr ffff31600ee91488 by task kworker/5:1/211
CPU: 5 UID: 0 PID: 211 Comm: kworker/5:1 Not tainted 6.11.0-rc7-00382-gfc6c92196396 #22
Hardware name: linux,dummy-virt (DT)
Workqueue: events binder_deferred_func
Call trace:
binder_release_work+0x398/0x3d0
binder_deferred_func+0xb60/0x109c
process_one_work+0x51c/0xbd4
worker_thread+0x608/0xee8
Allocated by task 703:
__kmalloc_cache_noprof+0x130/0x280
binder_thread_write+0xdb4/0x42a0
binder_ioctl+0x18f0/0x25ac
__arm64_sys_ioctl+0x124/0x190
invoke_syscall+0x6c/0x254
Freed by task 211:
kfree+0xc4/0x230
binder_deferred_func+0xae8/0x109c
process_one_work+0x51c/0xbd4
worker_thread+0x608/0xee8
==================================================================
This commit fixes the issue by ensuring any queued freeze work is removed
when cleaning up a binder reference.
Fixes: d579b04a52 ("binder: frozen notification")
Cc: stable@vger.kernel.org
Acked-by: Todd Kjos <tkjos@android.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20240926233632.821189-4-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In binder_add_freeze_work() we iterate over the proc->nodes with the
proc->inner_lock held. However, this lock is temporarily dropped to
acquire the node->lock first (lock nesting order). This can race with
binder_deferred_release() which removes the nodes from the proc->nodes
rbtree and adds them into binder_dead_nodes list. This leads to a broken
iteration in binder_add_freeze_work() as rb_next() will use data from
binder_dead_nodes, triggering an out-of-bounds access:
==================================================================
BUG: KASAN: global-out-of-bounds in rb_next+0xfc/0x124
Read of size 8 at addr ffffcb84285f7170 by task freeze/660
CPU: 8 UID: 0 PID: 660 Comm: freeze Not tainted 6.11.0-07343-ga727812a8d45 #18
Hardware name: linux,dummy-virt (DT)
Call trace:
rb_next+0xfc/0x124
binder_add_freeze_work+0x344/0x534
binder_ioctl+0x1e70/0x25ac
__arm64_sys_ioctl+0x124/0x190
The buggy address belongs to the variable:
binder_dead_nodes+0x10/0x40
[...]
==================================================================
This is possible because proc->nodes (rbtree) and binder_dead_nodes
(list) share entries in binder_node through a union:
struct binder_node {
[...]
union {
struct rb_node rb_node;
struct hlist_node dead_node;
};
Fix the race by checking that the proc is still alive. If not, simply
break out of the iteration.
Fixes: d579b04a52 ("binder: frozen notification")
Cc: stable@vger.kernel.org
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20240926233632.821189-3-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In binder_add_freeze_work() we iterate over the proc->nodes with the
proc->inner_lock held. However, this lock is temporarily dropped in
order to acquire the node->lock first (lock nesting order). This can
race with binder_node_release() and trigger a use-after-free:
==================================================================
BUG: KASAN: slab-use-after-free in _raw_spin_lock+0xe4/0x19c
Write of size 4 at addr ffff53c04c29dd04 by task freeze/640
CPU: 5 UID: 0 PID: 640 Comm: freeze Not tainted 6.11.0-07343-ga727812a8d45 #17
Hardware name: linux,dummy-virt (DT)
Call trace:
_raw_spin_lock+0xe4/0x19c
binder_add_freeze_work+0x148/0x478
binder_ioctl+0x1e70/0x25ac
__arm64_sys_ioctl+0x124/0x190
Allocated by task 637:
__kmalloc_cache_noprof+0x12c/0x27c
binder_new_node+0x50/0x700
binder_transaction+0x35ac/0x6f74
binder_thread_write+0xfb8/0x42a0
binder_ioctl+0x18f0/0x25ac
__arm64_sys_ioctl+0x124/0x190
Freed by task 637:
kfree+0xf0/0x330
binder_thread_read+0x1e88/0x3a68
binder_ioctl+0x16d8/0x25ac
__arm64_sys_ioctl+0x124/0x190
==================================================================
Fix the race by taking a temporary reference on the node before
releasing the proc->inner lock. This ensures the node remains alive
while in use.
Fixes: d579b04a52 ("binder: frozen notification")
Cc: stable@vger.kernel.org
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20240926233632.821189-2-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Binder objects are processed and copied individually into the target
buffer during transactions. Any raw data in-between these objects is
copied as well. However, this raw data copy lacks an out-of-bounds
check. If the raw data exceeds the data section size then the copy
overwrites the offsets section. This eventually triggers an error that
attempts to unwind the processed objects. However, at this point the
offsets used to index these objects are now corrupted.
Unwinding with corrupted offsets can result in decrements of arbitrary
nodes and lead to their premature release. Other users of such nodes are
left with a dangling pointer triggering a use-after-free. This issue is
made evident by the following KASAN report (trimmed):
==================================================================
BUG: KASAN: slab-use-after-free in _raw_spin_lock+0xe4/0x19c
Write of size 4 at addr ffff47fc91598f04 by task binder-util/743
CPU: 9 UID: 0 PID: 743 Comm: binder-util Not tainted 6.11.0-rc4 #1
Hardware name: linux,dummy-virt (DT)
Call trace:
_raw_spin_lock+0xe4/0x19c
binder_free_buf+0x128/0x434
binder_thread_write+0x8a4/0x3260
binder_ioctl+0x18f0/0x258c
[...]
Allocated by task 743:
__kmalloc_cache_noprof+0x110/0x270
binder_new_node+0x50/0x700
binder_transaction+0x413c/0x6da8
binder_thread_write+0x978/0x3260
binder_ioctl+0x18f0/0x258c
[...]
Freed by task 745:
kfree+0xbc/0x208
binder_thread_read+0x1c5c/0x37d4
binder_ioctl+0x16d8/0x258c
[...]
==================================================================
To avoid this issue, let's check that the raw data copy is within the
boundaries of the data section.
Fixes: 6d98eb95b4 ("binder: avoid potential data leakage when copying txn")
Cc: Todd Kjos <tkjos@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20240822182353.2129600-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Frozen processes present a significant challenge in binder transactions.
When a process is frozen, it cannot, by design, accept and/or respond to
binder transactions. As a result, the sender needs to adjust its
behavior, such as postponing transactions until the peer process
unfreezes. However, there is currently no way to subscribe to these
state change events, making it impossible to implement frozen-aware
behaviors efficiently.
Introduce a binder API for subscribing to frozen state change events.
This allows programs to react to changes in peer process state,
mitigating issues related to binder transactions sent to frozen
processes.
Implementation details:
For a given binder_ref, the state of frozen notification can be one of
the followings:
1. Userspace doesn't want a notification. binder_ref->freeze is null.
2. Userspace wants a notification but none is in flight.
list_empty(&binder_ref->freeze->work.entry) = true
3. A notification is in flight and waiting to be read by userspace.
binder_ref_freeze.sent is false.
4. A notification was read by userspace and kernel is waiting for an ack.
binder_ref_freeze.sent is true.
When a notification is in flight, new state change events are coalesced into
the existing binder_ref_freeze struct. If userspace hasn't picked up the
notification yet, the driver simply rewrites the state. Otherwise, the
notification is flagged as requiring a resend, which will be performed
once userspace acks the original notification that's inflight.
See https://r.android.com/3070045 for how userspace is going to use this
feature.
Signed-off-by: Yu-Ting Tseng <yutingtseng@google.com>
Acked-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20240709070047.4055369-4-yutingtseng@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In commit 15d9da3f81 ("binder: use bitmap for faster descriptor
lookup"), it was incorrectly assumed that references to the context
manager node should always get descriptor zero assigned to them.
However, if the context manager dies and a new process takes its place,
then assigning descriptor zero to the new context manager might lead to
collisions, as there could still be references to the older node. This
issue was reported by syzbot with the following trace:
kernel BUG at drivers/android/binder.c:1173!
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 447 Comm: binder-util Not tainted 6.10.0-rc6-00348-g31643d84b8c3 #10
Hardware name: linux,dummy-virt (DT)
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : binder_inc_ref_for_node+0x500/0x544
lr : binder_inc_ref_for_node+0x1e4/0x544
sp : ffff80008112b940
x29: ffff80008112b940 x28: ffff0e0e40310780 x27: 0000000000000000
x26: 0000000000000001 x25: ffff0e0e40310738 x24: ffff0e0e4089ba34
x23: ffff0e0e40310b00 x22: ffff80008112bb50 x21: ffffaf7b8f246970
x20: ffffaf7b8f773f08 x19: ffff0e0e4089b800 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 000000002de4aa60
x14: 0000000000000000 x13: 2de4acf000000000 x12: 0000000000000020
x11: 0000000000000018 x10: 0000000000000020 x9 : ffffaf7b90601000
x8 : ffff0e0e48739140 x7 : 0000000000000000 x6 : 000000000000003f
x5 : ffff0e0e40310b28 x4 : 0000000000000000 x3 : ffff0e0e40310720
x2 : ffff0e0e40310728 x1 : 0000000000000000 x0 : ffff0e0e40310710
Call trace:
binder_inc_ref_for_node+0x500/0x544
binder_transaction+0xf68/0x2620
binder_thread_write+0x5bc/0x139c
binder_ioctl+0xef4/0x10c8
[...]
This patch adds back the previous behavior of assigning the next
non-zero descriptor if references to previous context managers still
exist. It amends both strategies, the newer dbitmap code and also the
legacy slow_desc_lookup_olocked(), by allowing them to start looking
for available descriptors at a given offset.
Fixes: 15d9da3f81 ("binder: use bitmap for faster descriptor lookup")
Cc: stable@vger.kernel.org
Reported-and-tested-by: syzbot+3dae065ca76952a67257@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000c1c0a0061d1e6979@google.com/
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20240722150512.4192473-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With the introduction of binder_available_for_proc_work_ilocked() in
commit 1b77e9dcc3 ("ANDROID: binder: remove proc waitqueue") a binder
thread can only "wait_for_proc_work" after its thread->looper has been
marked as BINDER_LOOPER_STATE_{ENTERED|REGISTERED}.
This means an unregistered reader risks waiting indefinitely for work
since it never gets added to the proc->waiting_threads. If there are no
further references to its waitqueue either the task will hang. The same
applies to readers using the (e)poll interface.
I couldn't find the rationale behind this restriction. So this patch
restores the previous behavior of allowing unregistered threads to
"wait_for_proc_work". Note that an error message for this scenario,
which had previously become unreachable, is now re-enabled.
Fixes: 1b77e9dcc3 ("ANDROID: binder: remove proc waitqueue")
Cc: stable@vger.kernel.org
Cc: Martijn Coenen <maco@google.com>
Cc: Arve Hjønnevåg <arve@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20240711201452.2017543-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When creating new binder references, the driver assigns a descriptor id
that is shared with userspace. Regrettably, the driver needs to keep the
descriptors small enough to accommodate userspace potentially using them
as Vector indexes. Currently, the driver performs a linear search on the
rb-tree of references to find the smallest available descriptor id. This
approach, however, scales poorly as the number of references grows.
This patch introduces the usage of bitmaps to boost the performance of
descriptor assignments. This optimization results in notable performance
gains, particularly in processes with a large number of references. The
following benchmark with 100,000 references showcases the difference in
latency between the dbitmap implementation and the legacy approach:
[ 587.145098] get_ref_desc_olocked: 15us (dbitmap on)
[ 602.788623] get_ref_desc_olocked: 47343us (dbitmap off)
Note the bitmap size is dynamically adjusted in line with the number of
references, ensuring efficient memory usage. In cases where growing the
bitmap is not possible, the driver falls back to the slow legacy method.
A previous attempt to solve this issue was proposed in [1]. However,
such method involved adding new ioctls which isn't great, plus older
userspace code would not have benefited from the optimizations either.
Link: https://lore.kernel.org/all/20240417191418.1341988-1-cmllamas@google.com/ [1]
Cc: Tim Murray <timmurray@google.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Martijn Coenen <maco@android.com>
Cc: Todd Kjos <tkjos@android.com>
Cc: John Stultz <jstultz@google.com>
Cc: Steven Moreland <smoreland@google.com>
Suggested-by: Nick Chen <chenjia3@oppo.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20240612042535.1556708-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 6d98eb95b4 ("binder: avoid potential data leakage when copying
txn") introduced changes to how binder objects are copied. In doing so,
it unintentionally removed an offset alignment check done through calls
to binder_alloc_copy_from_buffer() -> check_buffer().
These calls were replaced in binder_get_object() with copy_from_user(),
so now an explicit offset alignment check is needed here. This avoids
later complications when unwinding the objects gets harder.
It is worth noting this check existed prior to commit 7a67a39320
("binder: add function to copy binder object from buffer"), likely
removed due to redundancy at the time.
Fixes: 6d98eb95b4 ("binder: avoid potential data leakage when copying txn")
Cc: stable@vger.kernel.org
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Acked-by: Todd Kjos <tkjos@google.com>
Link: https://lore.kernel.org/r/20240330190115.1877819-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
