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2025-11-26android: binderfs: add missing parameters in binder_ctl_ioctl()'s docSunday Adelodun-0/+3
The kernel-doc comment for binder_ctl_ioctl() lacks descriptions for the @file, @cmd, and @arg parameters, which triggers warnings during documentation builds. Add the missing parameter descriptions to keep the kernel-doc consistent and free of warnings. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202511201725.ni2HZ2PP-lkp@intel.com/ Signed-off-by: Sunday Adelodun <adelodunolaoluwa@yahoo.com> Link: https://patch.msgid.link/20251121111203.21800-1-adelodunolaoluwa@yahoo.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-26rust_binder: move BC_FREE_BUFFER drop inside if statementAlice Ryhl-2/+2
When looking at flamegraphs, there is a pretty large entry for the function call drop_in_place::<Option<Allocation>> which in turn calls drop_in_place::<Allocation>. Combined with the looper_need_return condition, this means that the generated code looks like this: if let Some(buffer) = buffer { if buffer.looper_need_return_on_free() { self.inner.lock().looper_need_return = true; } } drop_in_place::<Option<Allocation>>() { // not inlined if let Some(buffer) = buffer { drop_in_place::<Allocation>(buffer); } } This kind of situation where you check X and then check X again is normally optimized into a single condition, but in this case due to the non-inlined function call to drop_in_place::<Option<Allocation>>, that optimization does not happen. Furthermore, the drop_in_place::<Allocation> call is only two-thirds of the drop_in_place::<Option<Allocation>> call in the flamegraph. This indicates that this double condition is not performing well. Also, last time I looked at Binder perf, I remember finding that the destructor of Allocation was involved with many branch mispredictions. Thus, change this code to look like this: if let Some(buffer) = buffer { if buffer.looper_need_return_on_free() { self.inner.lock().looper_need_return = true; } drop_in_place::<Allocation>(buffer); } by dropping the Allocation directly. Flamegraphs confirm that the drop_in_place::<Option<Allocation>> call disappears from this change. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Carlos Llamas <cmllamas@google.com> Link: https://patch.msgid.link/20251029-binder-bcfreebuf-option-v1-1-4d282be0439f@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-26rust_binder: use compat_ptr_ioctlAlice Ryhl-28/+3
Binder always treats the ioctl argument as a pointer. In this scenario, the idiomatic way to implement compat_ioctl is to use compat_ptr_ioctl. Thus update Rust Binder to do that. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Carlos Llamas <cmllamas@google.com> Link: https://patch.msgid.link/20251031-binder-compatptrioctl-v2-1-3d05b5cc058e@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-26binder: mark binder_alloc_exhaustive_test as slowCarlos Llamas-1/+1
The binder_alloc_exhaustive_test kunit test takes over 30s to complete and the kunit framework reports: # binder_alloc_exhaustive_test: Test should be marked slow (runtime: 33.842881934s) Mark the test as suggested to silence the warning. Cc: Tiffany Yang <ynaffit@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Tiffany Yang <ynaffit@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20251024161525.1732874-1-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-25tools: ynl-gen: add regeneration commentAsbjørn Sloth Tønnesen-0/+2
Add a comment on regeneration to the generated files. The comment is placed after the YNL-GEN line[1], as to not interfere with ynl-regen.sh's detection logic. [1] and after the optional YNL-ARG line. Link: https://lore.kernel.org/r/aR5m174O7pklKrMR@zx2c4.com/ Suggested-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net> Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20251120174429.390574-3-ast@fiberby.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-17convert rust_binderfsAl Viro-88/+33
Parallel to binderfs stuff: * use simple_start_creating()/simple_done_creating()/d_make_persistent() instead of manual inode_lock()/lookup_noperm()/d_instanitate()/inode_unlock(). * allocate inode first - simpler cleanup that way. * use simple_recursive_removal() instead of open-coding it. * switch to kill_anon_super() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-11-16rust: rbtree: add immutable cursorVitaly Wool-4/+4
Sometimes we may need to iterate over, or find an element in a read only (or read mostly) red-black tree, and in that case we don't need a mutable reference to the tree, which we'll however have to take to be able to use the current (mutable) cursor implementation. This patch adds a simple immutable cursor implementation to RBTree, which enables us to use an immutable tree reference. The existing (fully featured) cursor implementation is renamed to CursorMut, while retaining its functionality. The only existing user of the [mutable] cursor for RBTrees (binder) is updated to match the changes. Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.se> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20251014123339.2492210-1-vitaly.wool@konsulko.se [ Applied `rustfmt`. Added intra-doc link. Fixed unclosed example. Fixed docs description. Fixed typo and other formatting nits. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-11-16convert binderfsAl Viro-19/+14
Objects are created either by d_alloc_name()+d_add() (in binderfs_ctl_create()) or by simple_start_creating()+d_instantiate(). Removals are by simple_recurisive_removal(). Switch d_add()/d_instantiate() to d_make_persistent() + dput(). Voila - kill_litter_super() is not needed anymore. Fold dput()+unlocking the parent into simple_done_creating(), while we are at it. NOTE: return value of binderfs_create_file() is borrowed; it may get stored in proc->binderfs_entry. See binder_release()... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-11-16binderfs_binder_ctl_create(): kill a bogus checkAl Viro-6/+0
It's called once, during binderfs mount, right after allocating root dentry. Checking that it hadn't been already called is only obfuscating things. Looks like that bogosity had been copied from devpts... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-11-16binderfs: use simple_start_creating()Al Viro-38/+5
binderfs_binder_device_create() gets simpler, binderfs_create_dentry() simply goes away... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-10-22binder: remove "invalid inc weak" checkAlice Ryhl-10/+1
There are no scenarios where a weak increment is invalid on binder_node. The only possible case where it could be invalid is if the kernel delivers BR_DECREFS to the process that owns the node, and then increments the weak refcount again, effectively "reviving" a dead node. However, that is not possible: when the BR_DECREFS command is delivered, the kernel removes and frees the binder_node. The fact that you were able to call binder_inc_node_nilocked() implies that the node is not yet destroyed, which implies that BR_DECREFS has not been delivered to userspace, so incrementing the weak refcount is valid. Note that it's currently possible to trigger this condition if the owner calls BINDER_THREAD_EXIT while node->has_weak_ref is true. This causes BC_INCREFS on binder_ref instances to fail when they should not. Cc: stable@vger.kernel.org Fixes: 457b9a6f09f0 ("Staging: android: add binder driver") Reported-by: Yu-Ting Tseng <yutingtseng@google.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20251015-binder-weak-inc-v1-1-7914b092c371@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-22rust: replace `CStr` with `core::ffi::CStr`Tamir Duberstein-1/+1
`kernel::ffi::CStr` was introduced in commit d126d2380131 ("rust: str: add `CStr` type") in November 2022 as an upstreaming of earlier work that was done in May 2021[0]. That earlier work, having predated the inclusion of `CStr` in `core`, largely duplicated the implementation of `std::ffi::CStr`. `std::ffi::CStr` was moved to `core::ffi::CStr` in Rust 1.64 in September 2022. Hence replace `kernel::str::CStr` with `core::ffi::CStr` to reduce our custom code footprint, and retain needed custom functionality through an extension trait. Add `CStr` to `ffi` and the kernel prelude. Link: https://github.com/Rust-for-Linux/linux/commit/faa3cbcca03d0dec8f8e43f1d8d5c0860d98a23f [0] Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Danilo Krummrich <dakr@kernel.org> Reviewed-by: Benno Lossin <lossin@kernel.org> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Link: https://patch.msgid.link/20251018-cstr-core-v18-16-9378a54385f8@gmail.com [ Removed assert that would now depend on the Rust version. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-10-20rust_binder: use `core::ffi::CStr` method namesTamir Duberstein-2/+2
Prepare for `core::ffi::CStr` taking the place of `kernel::str::CStr` by avoiding methods that only exist on the latter. This backslid in commit eafedbc7c050 ("rust_binder: add Rust Binder driver"). Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Link: https://patch.msgid.link/20251018-cstr-core-v18-4-9378a54385f8@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-10-20rust_binder: use `kernel::fmt`Tamir Duberstein-2/+3
Reduce coupling to implementation details of the formatting machinery by avoiding direct use for `core`'s formatting traits and macros. This backslid in commit eafedbc7c050 ("rust_binder: add Rust Binder driver"). Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Link: https://patch.msgid.link/20251018-cstr-core-v18-3-9378a54385f8@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-10-20rust_binder: remove trailing commaTamir Duberstein-1/+1
This prepares for a later commit in which we introduce a custom formatting macro; that macro doesn't handle trailing commas so just remove this one. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Link: https://patch.msgid.link/20251018-cstr-core-v18-2-9378a54385f8@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-10-13binder: Fix missing kernel-doc entries in binder.cKriish Sharma-13/+14
Fix several kernel-doc warnings in `drivers/android/binder.c` caused by undocumented struct members and function parameters. In particular, add missing documentation for the `@thread` parameter in binder_free_buf_locked(). Signed-off-by: Kriish Sharma <kriish.sharma2006@gmail.com> Acked-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-13rust_binder: report freeze notification only when fully frozenAlice Ryhl-14/+42
Binder only sends out freeze notifications when ioctl_freeze() completes and the process has become fully frozen. However, if a freeze notification is registered during the freeze operation, then it registers an initial state of 'frozen'. This is a problem because if the freeze operation fails, then the listener is not told about that state change, leading to lost updates. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-13rust_binder: don't delete FreezeListener if there are pending duplicatesAlice Ryhl-1/+10
When userspace issues commands to a freeze listener, it identifies it using a cookie. Normally this cookie uniquely identifies a freeze listener, but when userspace clears a listener with the intent of deleting it, it's allowed to "regret" clearing it and create a new freeze listener for the same node using the same cookie. (IMO this was an API mistake, but userspace relies on it.) Currently if the active freeze listener gets fully deleted while there are still pending duplicates, then the code incorrectly deletes the pending duplicates too. To fix this, do not delete the entry if there are still pending duplicates. Since the current data structure requires a main freeze listener, we convert one pending duplicate into the primary listener in this scenario. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-13rust_binder: freeze_notif_done should resend if wrong stateAlice Ryhl-2/+3
Consider the following scenario: 1. A freeze notification is delivered to thread 1. 2. The process becomes frozen or unfrozen. 3. The message for step 2 is delivered to thread 2 and ignored because there is already a pending notification from step 1. 4. Thread 1 acknowledges the notification from step 1. In this case, step 4 should ensure that the message ignored in step 3 is resent as it can now be delivered. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-13rust_binder: remove warning about orphan mappingsAlice Ryhl-4/+0
This condition occurs if a thread dies while processing a transaction. We should not print anything in this scenario. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com> Acked-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-13rust_binder: clean `clippy::mem_replace_with_default` warningMiguel Ojeda-1/+1
Clippy reports: error: replacing a value of type `T` with `T::default()` is better expressed using `core::mem::take` --> drivers/android/binder/node.rs:690:32 | 690 | _unused_capacity = mem::replace(&mut inner.freeze_list, KVVec::new()); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `core::mem::take(&mut inner.freeze_list)` | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#mem_replace_with_default = note: `-D clippy::mem-replace-with-default` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(clippy::mem_replace_with_default)]` The suggestion seems fine, thus apply it. Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-19rust_binder: add Rust Binder driverAlice Ryhl-1/+10264
We're generally not proponents of rewrites (nasty uncomfortable things that make you late for dinner!). So why rewrite Binder? Binder has been evolving over the past 15+ years to meet the evolving needs of Android. Its responsibilities, expectations, and complexity have grown considerably during that time. While we expect Binder to continue to evolve along with Android, there are a number of factors that currently constrain our ability to develop/maintain it. Briefly those are: 1. Complexity: Binder is at the intersection of everything in Android and fulfills many responsibilities beyond IPC. It has become many things to many people, and due to its many features and their interactions with each other, its complexity is quite high. In just 6kLOC it must deliver transactions to the right threads. It must correctly parse and translate the contents of transactions, which can contain several objects of different types (e.g., pointers, fds) that can interact with each other. It controls the size of thread pools in userspace, and ensures that transactions are assigned to threads in ways that avoid deadlocks where the threadpool has run out of threads. It must track refcounts of objects that are shared by several processes by forwarding refcount changes between the processes correctly. It must handle numerous error scenarios and it combines/nests 13 different locks, 7 reference counters, and atomic variables. Finally, It must do all of this as fast and efficiently as possible. Minor performance regressions can cause a noticeably degraded user experience. 2. Things to improve: Thousand-line functions [1], error-prone error handling [2], and confusing structure can occur as a code base grows organically. After more than a decade of development, this codebase could use an overhaul. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/android/binder.c?h=v6.5#n2896 [2]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/android/binder.c?h=v6.5#n3658 3. Security critical: Binder is a critical part of Android's sandboxing strategy. Even Android's most de-privileged sandboxes (e.g. the Chrome renderer, or SW Codec) have direct access to Binder. More than just about any other component, it's important that Binder provide robust security, and itself be robust against security vulnerabilities. It's #1 (high complexity) that has made continuing to evolve Binder and resolving #2 (tech debt) exceptionally difficult without causing #3 (security issues). For Binder to continue to meet Android's needs, we need better ways to manage (and reduce!) complexity without increasing the risk. The biggest change is obviously the choice of programming language. We decided to use Rust because it directly addresses a number of the challenges within Binder that we have faced during the last years. It prevents mistakes with ref counting, locking, bounds checking, and also does a lot to reduce the complexity of error handling. Additionally, we've been able to use the more expressive type system to encode the ownership semantics of the various structs and pointers, which takes the complexity of managing object lifetimes out of the hands of the programmer, reducing the risk of use-after-frees and similar problems. Rust has many different pointer types that it uses to encode ownership semantics into the type system, and this is probably one of the most important aspects of how it helps in Binder. The Binder driver has a lot of different objects that have complex ownership semantics; some pointers own a refcount, some pointers have exclusive ownership, and some pointers just reference the object and it is kept alive in some other manner. With Rust, we can use a different pointer type for each kind of pointer, which enables the compiler to enforce that the ownership semantics are implemented correctly. Another useful feature is Rust's error handling. Rust allows for more simplified error handling with features such as destructors, and you get compilation failures if errors are not properly handled. This means that even though Rust requires you to spend more lines of code than C on things such as writing down invariants that are left implicit in C, the Rust driver is still slightly smaller than C binder: Rust is 5.5kLOC and C is 5.8kLOC. (These numbers are excluding blank lines, comments, binderfs, and any debugging facilities in C that are not yet implemented in the Rust driver. The numbers include abstractions in rust/kernel/ that are unlikely to be used by other drivers than Binder.) Although this rewrite completely rethinks how the code is structured and how assumptions are enforced, we do not fundamentally change *how* the driver does the things it does. A lot of careful thought has gone into the existing design. The rewrite is aimed rather at improving code health, structure, readability, robustness, security, maintainability and extensibility. We also include more inline documentation, and improve how assumptions in the code are enforced. Furthermore, all unsafe code is annotated with a SAFETY comment that explains why it is correct. We have left the binderfs filesystem component in C. Rewriting it in Rust would be a large amount of work and requires a lot of bindings to the file system interfaces. Binderfs has not historically had the same challenges with security and complexity, so rewriting binderfs seems to have lower value than the rest of Binder. Correctness and feature parity ------------------------------ Rust binder passes all tests that validate the correctness of Binder in the Android Open Source Project. We can boot a device, and run a variety of apps and functionality without issues. We have performed this both on the Cuttlefish Android emulator device, and on a Pixel 6 Pro. As for feature parity, Rust binder currently implements all features that C binder supports, with the exception of some debugging facilities. The missing debugging facilities will be added before we submit the Rust implementation upstream. Tracepoints ----------- I did not include all of the tracepoints as I felt that the mechansim for making C access fields of Rust structs should be discussed on list separately. I also did not include the support for building Rust Binder as a module since that requires exporting a bunch of additional symbols on the C side. Original RFC Link with old benchmark numbers: https://lore.kernel.org/r/20231101-rust-binder-v1-0-08ba9197f637@google.com Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> Co-developed-by: Matt Gilbride <mattgilbride@google.com> Signed-off-by: Matt Gilbride <mattgilbride@google.com> Acked-by: Carlos Llamas <cmllamas@google.com> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20250919-rust-binder-v2-1-a384b09f28dd@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-18binder: fix double-free in dbitmapCarlos Llamas-0/+1
A process might fail to allocate a new bitmap when trying to expand its proc->dmap. In that case, dbitmap_grow() fails and frees the old bitmap via dbitmap_free(). However, the driver calls dbitmap_free() again when the same process terminates, leading to a double-free error: ================================================================== BUG: KASAN: double-free in binder_proc_dec_tmpref+0x2e0/0x55c Free of addr ffff00000b7c1420 by task kworker/9:1/209 CPU: 9 UID: 0 PID: 209 Comm: kworker/9:1 Not tainted 6.17.0-rc6-dirty #5 PREEMPT Hardware name: linux,dummy-virt (DT) Workqueue: events binder_deferred_func Call trace: kfree+0x164/0x31c binder_proc_dec_tmpref+0x2e0/0x55c binder_deferred_func+0xc24/0x1120 process_one_work+0x520/0xba4 [...] Allocated by task 448: __kmalloc_noprof+0x178/0x3c0 bitmap_zalloc+0x24/0x30 binder_open+0x14c/0xc10 [...] Freed by task 449: kfree+0x184/0x31c binder_inc_ref_for_node+0xb44/0xe44 binder_transaction+0x29b4/0x7fbc binder_thread_write+0x1708/0x442c binder_ioctl+0x1b50/0x2900 [...] ================================================================== Fix this issue by marking proc->map NULL in dbitmap_free(). Cc: stable@vger.kernel.org Fixes: 15d9da3f818c ("binder: use bitmap for faster descriptor lookup") Signed-off-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Tiffany Yang <ynaffit@google.com> Link: https://lore.kernel.org/r/20250915221248.3470154-1-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-19binder: add tracepoint for netlink reportsCarlos Llamas-0/+39
Add a tracepoint to capture the same details that are being sent through the generic netlink interface during transaction failures. This provides a useful debugging tool to observe the events independently from the netlink listeners. Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20250727182932.2499194-6-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-19binder: add transaction_report feature entryLi Li-0/+8
Add "transaction_report" to the binderfs feature list, to help userspace determine if the "BINDER_CMD_REPORT" generic netlink api is supported by the binder driver. Signed-off-by: Li Li <dualli@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20250727182932.2499194-5-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-19binder: introduce transaction reports via netlinkLi Li-5/+134
Introduce a generic netlink multicast event to report binder transaction failures to userspace. This allows subscribers to monitor these events and take appropriate actions, such as stopping a misbehaving application that is spamming a service with huge amount of transactions. The multicast event contains full details of the failed transactions, including the sender/target PIDs, payload size and specific error code. This interface is defined using a YAML spec, from which the UAPI and kernel headers and source are auto-generated. Signed-off-by: Li Li <dualli@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20250727182932.2499194-4-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-19binder: add t->is_async and t->is_replyCarlos Llamas-5/+6
Replace the t->need_reply flag with the more descriptive t->is_async and and t->is_reply flags. The 'need_reply' flag was only used for debugging purposes and the new flags can be used to distinguish between the type of transactions too: sync, async and reply. For now, only update the logging in print_binder_transaction_ilocked(). However, the new flags can be used in the future to replace the current patterns and improve readability. e.g.: - if (!reply && !(tr->flags & TF_ONE_WAY)) + if (t->is_async) This patch is in preparation for binder's generic netlink implementation and no functional changes are intended. Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20250727182932.2499194-3-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-19binder: pre-allocate binder_transactionCarlos Llamas-34/+30
Move the allocation of 'struct binder_transaction' to the beginning of the binder_transaction() function, along with the initialization of all the members that are known at that time. This minor refactoring helps to consolidate the usage of transaction information at later points. This patch is in preparation for binder's generic netlink implementation and no functional changes are intended. Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20250727182932.2499194-2-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-18binder: remove MODULE_LICENSE()Carlos Llamas-2/+0
The MODULE_LICENSE() macro is intended for drivers that can be built as loadable modules. The binder driver is always built-in, using this macro here is unnecessary and potentially confusing. Remove it. Cc: Salvatore Bonaccorso <carnil@debian.org> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20250817135034.3692902-1-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-29Merge tag 'char-misc-6.17-rc1' of ↵Linus Torvalds-405/+657
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char / misc / IIO / other driver updates from Greg KH: "Here is the big set of char/misc/iio and other smaller driver subsystems for 6.17-rc1. It's a big set this time around, with the huge majority being in the iio subsystem with new drivers and dts files being added there. Highlights include: - IIO driver updates, additions, and changes making more code const and cleaning up some init logic - bus_type constant conversion changes - misc device test functions added - rust miscdevice minor fixup - unused function removals for some drivers - mei driver updates - mhi driver updates - interconnect driver updates - Android binder updates and test infrastructure added - small cdx driver updates - small comedi fixes - small nvmem driver updates - small pps driver updates - some acrn virt driver fixes for printk messages - other small driver updates All of these have been in linux-next with no reported issues" * tag 'char-misc-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (292 commits) binder: Use seq_buf in binder_alloc kunit tests binder: Add copyright notice to new kunit files misc: ti_fpc202: Switch to of_fwnode_handle() bus: moxtet: Use dev_fwnode() pc104: move PC104 option to drivers/Kconfig drivers: virt: acrn: Don't use %pK through printk comedi: fix race between polling and detaching interconnect: qcom: Add Milos interconnect provider driver dt-bindings: interconnect: document the RPMh Network-On-Chip Interconnect in Qualcomm Milos SoC mei: more prints with client prefix mei: bus: use cldev in prints bus: mhi: host: pci_generic: Add Telit FN990B40 modem support bus: mhi: host: Detect events pointing to unexpected TREs bus: mhi: host: pci_generic: Add Foxconn T99W696 modem bus: mhi: host: Use str_true_false() helper bus: mhi: host: pci_generic: Add support for EM929x and set MRU to 32768 for better performance. bus: mhi: host: Fix endianness of BHI vector table bus: mhi: host: pci_generic: Disable runtime PM for QDU100 bus: mhi: host: pci_generic: Fix the modem name of Foxconn T99W640 dt-bindings: interconnect: qcom,msm8998-bwmon: Allow 'nonposted-mmio' ...
2025-07-28Merge tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds-14/+6
Pull misc VFS updates from Al Viro: "VFS-related cleanups in various places (mostly of the "that really can't happen" or "there's a better way to do it" variety)" * tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: gpib: use file_inode() binder_ioctl_write_read(): simplify control flow a bit secretmem: move setting O_LARGEFILE and bumping users' count to the place where we create the file apparmor: file never has NULL f_path.mnt landlock: opened file never has a negative dentry
2025-07-24binder: Use seq_buf in binder_alloc kunit testsTiffany Yang-25/+21
Replace instances of snprintf with seq_buf functions, as suggested by Kees [1]. [1] https://lore.kernel.org/all/202507160743.15E8044@keescook/ Fixes: d1934ed9803c ("binder: encapsulate individual alloc test cases") Suggested-by: Kees Cook <kees@kernel.org> Cc: Joel Fernandes <joelagnelf@nvidia.com> Signed-off-by: Tiffany Yang <ynaffit@google.com> Reviewed-by: Kees Cook <kees@kernel.org> Link: https://lore.kernel.org/r/20250722234508.232228-2-ynaffit@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-24binder: Add copyright notice to new kunit filesTiffany Yang-1/+11
Clean up for the binder_alloc kunit test series. Add a copyright notice to new files, as suggested by Carlos [1]. [1] https://lore.kernel.org/all/CAFuZdDLD=3CBOLSWw3VxCf7Nkf884SSNmt1wresQgxgBwED=eQ@mail.gmail.com/ Fixes: 5e024582f494 ("binder: Scaffolding for binder_alloc KUnit tests") Suggested-by: Carlos Llamas <cmllamas@google.com> Cc: Joel Fernandes <joelagnelf@nvidia.com> Signed-off-by: Tiffany Yang <ynaffit@google.com> Link: https://lore.kernel.org/r/20250722234508.232228-1-ynaffit@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-16binder: encapsulate individual alloc test casesTiffany Yang-53/+181
Each case tested by the binder allocator test is defined by 3 parameters: the end alignment type of each requested buffer allocation, whether those buffers share the front or back pages of the allotted address space, and the order in which those buffers should be released. The alignment type represents how a binder buffer may be laid out within or across page boundaries and relative to other buffers, and it's used along with whether the buffers cover part (sharing the front pages) of or all (sharing the back pages) of the vma to calculate the sizes passed into each test. binder_alloc_test_alloc recursively generates each possible arrangement of alignment types and then tests that the binder_alloc code tracks pages correctly when those buffers are allocated and then freed in every possible order at both ends of the address space. While they provide comprehensive coverage, they are poor candidates to be represented as KUnit test cases, which must be statically enumerated. For 5 buffers and 5 end alignment types, the test case array would have 750,000 entries. This change structures the recursive calls into meaningful test cases so that failures are easier to interpret. Signed-off-by: Tiffany Yang <ynaffit@google.com> Acked-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20250714185321.2417234-7-ynaffit@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-16binder: Convert binder_alloc selftests to KUnitTiffany Yang-366/+282
Convert the existing binder_alloc_selftest tests into KUnit tests. These tests allocate and free an exhaustive combination of buffers with various sizes and alignments. This change allows them to be run without blocking or otherwise interfering with other processes in binder. This test is refactored into more meaningful cases in the subsequent patch. Signed-off-by: Tiffany Yang <ynaffit@google.com> Acked-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20250714185321.2417234-6-ynaffit@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-16binder: Scaffolding for binder_alloc KUnit testsTiffany Yang-6/+208
Add setup and teardown for testing binder allocator code with KUnit. Include minimal test cases to verify that tests are initialized correctly. Tested-by: Rae Moar <rmoar@google.com> Signed-off-by: Tiffany Yang <ynaffit@google.com> Acked-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20250714185321.2417234-5-ynaffit@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-16binder: Store lru freelist in binder_allocTiffany Yang-20/+67
Store a pointer to the free pages list that the binder allocator should use for a process inside of struct binder_alloc. This change allows binder allocator code to be tested and debugged deterministically while a system is using binder; i.e., without interfering with other binder processes and independently of the shrinker. This is necessary to convert the current binder_alloc_selftest into a kunit test that does not rely on hijacking an existing binder_proc to run. A binder process's binder_alloc->freelist should not be changed after it is initialized. A sole exception is the process that runs the existing binder_alloc selftest. Its freelist can be temporarily replaced for the duration of the test because it runs as a single thread before any pages can be added to the global binder freelist, and the test frees every page it allocates before dropping the binder_selftest_lock. This exception allows the existing selftest to be used to check for regressions, but it will be dropped when the binder_alloc tests are converted to kunit in a subsequent patch in this series. Signed-off-by: Tiffany Yang <ynaffit@google.com> Acked-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20250714185321.2417234-3-ynaffit@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-16binder: Fix selftest page indexingTiffany Yang-1/+1
The binder allocator selftest was only checking the last page of buffers that ended on a page boundary. Correct the page indexing to account for buffers that are not page-aligned. Signed-off-by: Tiffany Yang <ynaffit@google.com> Acked-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20250714185321.2417234-2-ynaffit@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-16binder: use guards for plain mutex- and spinlock-protected sectionsDmitry Antipov-38/+17
Use 'guard(mutex)' and 'guard(spinlock)' for plain (i.e. non-scoped) mutex- and spinlock-protected sections, respectively, thus making locking a bit simpler. Briefly tested with 'stress-ng --binderfs'. Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20250626073054.7706-2-dmantipov@yandex.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-16binder: use kstrdup() in binderfs_binder_device_create()Dmitry Antipov-4/+1
In 'binderfs_binder_device_create()', use 'kstrdup()' to copy the newly created device's name, thus making the former a bit simpler. Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> Acked-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: "Tiffany Y. Yang" <ynaffit@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20250626073054.7706-1-dmantipov@yandex.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-02kill binderfs_remove_file()Al Viro-18/+1
don't try to open-code simple_recursive_removal(), especially when you miss things like d_invalidate()... Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-06-24binder: Remove unused binder lock eventsSteven Rostedt-21/+0
Trace events can take up to 5K each when they are defined, regardless if they are used or not. The binder lock events: binder_lock, binder_locked and binder_unlock are no longer used. Remove them. Fixes: a60b890f607d ("binder: remove global binder lock") Signed-off-by: "Steven Rostedt (Google)" <rostedt@goodmis.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20250612093408.3b7320fa@batman.local.home Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-24binder: fix reversed pid/tid in logCarlos Llamas-4/+2
The "pid:tid" format is used consistently throughout the driver's logs with the exception of this one place where the arguments are reversed. Let's fix that. Also, collapse a multi-line comment into a single line. Cc: Steven Moreland <smoreland@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20250605141930.1069438-1-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-17binder_ioctl_write_read(): simplify control flow a bitAl Viro-14/+6
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-06-06Merge tag 'char-misc-6.16-rc1' of ↵Linus Torvalds-89/+169
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char / misc / iio driver updates from Greg KH: "Here is the big char/misc/iio and other small driver subsystem pull request for 6.16-rc1. Overall, a lot of individual changes, but nothing major, just the normal constant forward progress of new device support and cleanups to existing subsystems. Highlights in here are: - Large IIO driver updates and additions and device tree changes - Android binder bugfixes and logfile fixes - mhi driver updates - comedi driver updates - counter driver updates and additions - coresight driver updates and additions - echo driver removal as there are no in-kernel users of it - nvmem driver updates - spmi driver updates - new amd-sbi driver "subsystem" and drivers added - rust miscdriver binding documentation fix - other small driver fixes and updates (uio, w1, acrn, hpet, xillybus, cardreader drivers, fastrpc and others) All of these have been in linux-next for quite a while with no reported problems" * tag 'char-misc-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (390 commits) binder: fix yet another UAF in binder_devices counter: microchip-tcb-capture: Add watch validation support dt-bindings: iio: adc: Add ROHM BD79100G iio: adc: add support for Nuvoton NCT7201 dt-bindings: iio: adc: add NCT7201 ADCs iio: chemical: Add driver for SEN0322 dt-bindings: trivial-devices: Document SEN0322 iio: adc: ad7768-1: reorganize driver headers iio: bmp280: zero-init buffer iio: ssp_sensors: optimalize -> optimize HID: sensor-hub: Fix typo and improve documentation iio: admv1013: replace redundant ternary operator with just len iio: chemical: mhz19b: Fix error code in probe() iio: adc: at91-sama5d2: use IIO_DECLARE_BUFFER_WITH_TS iio: accel: sca3300: use IIO_DECLARE_BUFFER_WITH_TS iio: adc: ad7380: use IIO_DECLARE_DMA_BUFFER_WITH_TS iio: adc: ad4695: rename AD4695_MAX_VIN_CHANNELS iio: adc: ad4695: use IIO_DECLARE_DMA_BUFFER_WITH_TS iio: introduce IIO_DECLARE_BUFFER_WITH_TS macros iio: make IIO_DMA_MINALIGN minimum of 8 bytes ...
2025-05-26Merge tag 'vfs-6.16-rc1.async.dir' of ↵Linus Torvalds-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs directory lookup updates from Christian Brauner: "This contains cleanups for the lookup_one*() family of helpers. We expose a set of functions with names containing "lookup_one_len" and others without the "_len". This difference has nothing to do with "len". It's rater a historical accident that can be confusing. The functions without "_len" take a "mnt_idmap" pointer. This is found in the "vfsmount" and that is an important question when choosing which to use: do you have a vfsmount, or are you "inside" the filesystem. A related question is "is permission checking relevant here?". nfsd and cachefiles *do* have a vfsmount but *don't* use the non-_len functions. They pass nop_mnt_idmap and refuse to work on filesystems which have any other idmap. This work changes nfsd and cachefile to use the lookup_one family of functions and to explictily pass &nop_mnt_idmap which is consistent with all other vfs interfaces used where &nop_mnt_idmap is explicitly passed. The remaining uses of the "_one" functions do not require permission checks so these are renamed to be "_noperm" and the permission checking is removed. This series also changes these lookup function to take a qstr instead of separate name and len. In many cases this simplifies the call" * tag 'vfs-6.16-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: VFS: change lookup_one_common and lookup_noperm_common to take a qstr Use try_lookup_noperm() instead of d_hash_and_lookup() outside of VFS VFS: rename lookup_one_len family to lookup_noperm and remove permission check cachefiles: Use lookup_one() rather than lookup_one_len() nfsd: Use lookup_one() rather than lookup_one_len() VFS: improve interface for lookup_one functions
2025-05-25binder: fix yet another UAF in binder_devicesCarlos Llamas-0/+1
Commit e77aff5528a18 ("binderfs: fix use-after-free in binder_devices") addressed a use-after-free where devices could be released without first being removed from the binder_devices list. However, there is a similar path in binder_free_proc() that was missed: ================================================================== BUG: KASAN: slab-use-after-free in binder_remove_device+0xd4/0x100 Write of size 8 at addr ffff0000c773b900 by task umount/467 CPU: 12 UID: 0 PID: 467 Comm: umount Not tainted 6.15.0-rc7-00138-g57483a362741 #9 PREEMPT Hardware name: linux,dummy-virt (DT) Call trace: binder_remove_device+0xd4/0x100 binderfs_evict_inode+0x230/0x2f0 evict+0x25c/0x5dc iput+0x304/0x480 dentry_unlink_inode+0x208/0x46c __dentry_kill+0x154/0x530 [...] Allocated by task 463: __kmalloc_cache_noprof+0x13c/0x324 binderfs_binder_device_create.isra.0+0x138/0xa60 binder_ctl_ioctl+0x1ac/0x230 [...] Freed by task 215: kfree+0x184/0x31c binder_proc_dec_tmpref+0x33c/0x4ac binder_deferred_func+0xc10/0x1108 process_one_work+0x520/0xba4 [...] ================================================================== Call binder_remove_device() within binder_free_proc() to ensure the device is removed from the binder_devices list before being kfreed. Cc: stable@vger.kernel.org Fixes: 12d909cac1e1 ("binderfs: add new binder devices to binder_devices") Reported-by: syzbot+4af454407ec393de51d6@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=4af454407ec393de51d6 Tested-by: syzbot+4af454407ec393de51d6@syzkaller.appspotmail.com Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20250524220758.915028-1-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21binder: Create safe versions of binder log filesTiffany Y. Yang-27/+79
Binder defines several seq_files that can be accessed via debugfs or binderfs. Some of these files (e.g., 'state' and 'transactions') contain more granular information about binder's internal state that is helpful for debugging, but they also leak userspace address data through user-defined 'cookie' or 'ptr' values. Consequently, access to these files must be heavily restricted. Add two new files, 'state_hashed' and 'transactions_hashed', that reproduce the information in the original files but use the kernel's raw pointer obfuscation to hash any potential user addresses. This approach allows systems to grant broader access to the new files without having to change the security policy around the existing ones. In practice, userspace populates these fields with user addresses, but within the driver, these values only serve as unique identifiers for their associated binder objects. Consequently, binder logs can obfuscate these values and still retain meaning. While this strategy prevents leaking information about the userspace memory layout in the existing log files, it also decouples log messages about binder objects from their user-defined identifiers. Acked-by: Carlos Llamas <cmllamas@google.com> Tested-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: "Tiffany Y. Yang" <ynaffit@google.com> Link: https://lore.kernel.org/r/20250510013435.1520671-7-ynaffit@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21binder: Refactor binder_node print synchronizationTiffany Y. Yang-51/+68
The binder driver outputs information about each dead binder node by iterating over the dead nodes list, and it prints the state of each live node in the system by traversing each binder_proc's proc->nodes tree. Both cases require similar logic to maintain the global lock ordering while accessing each node. Create a helper function to synchronize around printing binder nodes in a list. Opportunistically make minor cosmetic changes to binder print functions. Acked-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: "Tiffany Y. Yang" <ynaffit@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20250510013435.1520671-5-ynaffit@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21binder: fix use-after-free in binderfs_evict_inode()Dmitry Antipov-5/+20
Running 'stress-ng --binderfs 16 --timeout 300' under KASAN-enabled kernel, I've noticed the following: BUG: KASAN: slab-use-after-free in binderfs_evict_inode+0x1de/0x2d0 Write of size 8 at addr ffff88807379bc08 by task stress-ng-binde/1699 CPU: 0 UID: 0 PID: 1699 Comm: stress-ng-binde Not tainted 6.14.0-rc7-g586de92313fc-dirty #13 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x1c2/0x2a0 ? __pfx_dump_stack_lvl+0x10/0x10 ? __pfx__printk+0x10/0x10 ? __pfx_lock_release+0x10/0x10 ? __virt_addr_valid+0x18c/0x540 ? __virt_addr_valid+0x469/0x540 print_report+0x155/0x840 ? __virt_addr_valid+0x18c/0x540 ? __virt_addr_valid+0x469/0x540 ? __phys_addr+0xba/0x170 ? binderfs_evict_inode+0x1de/0x2d0 kasan_report+0x147/0x180 ? binderfs_evict_inode+0x1de/0x2d0 binderfs_evict_inode+0x1de/0x2d0 ? __pfx_binderfs_evict_inode+0x10/0x10 evict+0x524/0x9f0 ? __pfx_lock_release+0x10/0x10 ? __pfx_evict+0x10/0x10 ? do_raw_spin_unlock+0x4d/0x210 ? _raw_spin_unlock+0x28/0x50 ? iput+0x697/0x9b0 __dentry_kill+0x209/0x660 ? shrink_kill+0x8d/0x2c0 shrink_kill+0xa9/0x2c0 shrink_dentry_list+0x2e0/0x5e0 shrink_dcache_parent+0xa2/0x2c0 ? __pfx_shrink_dcache_parent+0x10/0x10 ? __pfx_lock_release+0x10/0x10 ? __pfx_do_raw_spin_lock+0x10/0x10 do_one_tree+0x23/0xe0 shrink_dcache_for_umount+0xa0/0x170 generic_shutdown_super+0x67/0x390 kill_litter_super+0x76/0xb0 binderfs_kill_super+0x44/0x90 deactivate_locked_super+0xb9/0x130 cleanup_mnt+0x422/0x4c0 ? lockdep_hardirqs_on+0x9d/0x150 task_work_run+0x1d2/0x260 ? __pfx_task_work_run+0x10/0x10 resume_user_mode_work+0x52/0x60 syscall_exit_to_user_mode+0x9a/0x120 do_syscall_64+0x103/0x210 ? asm_sysvec_apic_timer_interrupt+0x1a/0x20 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0xcac57b Code: c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 f3 0f 1e fa 31 f6 e9 05 00 00 00 0f 1f 44 00 00 f3 0f 1e fa b8 RSP: 002b:00007ffecf4226a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007ffecf422720 RCX: 0000000000cac57b RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffecf422850 RBP: 00007ffecf422850 R08: 0000000028d06ab1 R09: 7fffffffffffffff R10: 3fffffffffffffff R11: 0000000000000246 R12: 00007ffecf422718 R13: 00007ffecf422710 R14: 00007f478f87b658 R15: 00007ffecf422830 </TASK> Allocated by task 1705: kasan_save_track+0x3e/0x80 __kasan_kmalloc+0x8f/0xa0 __kmalloc_cache_noprof+0x213/0x3e0 binderfs_binder_device_create+0x183/0xa80 binder_ctl_ioctl+0x138/0x190 __x64_sys_ioctl+0x120/0x1b0 do_syscall_64+0xf6/0x210 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 1705: kasan_save_track+0x3e/0x80 kasan_save_free_info+0x46/0x50 __kasan_slab_free+0x62/0x70 kfree+0x194/0x440 evict+0x524/0x9f0 do_unlinkat+0x390/0x5b0 __x64_sys_unlink+0x47/0x50 do_syscall_64+0xf6/0x210 entry_SYSCALL_64_after_hwframe+0x77/0x7f This 'stress-ng' workload causes the concurrent deletions from 'binder_devices' and so requires full-featured synchronization to prevent list corruption. I've found this issue independently but pretty sure that syzbot did the same, so Reported-by: and Closes: should be applicable here as well. Cc: stable@vger.kernel.org Reported-by: syzbot+353d7b75658a95aa955a@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=353d7b75658a95aa955a Fixes: e77aff5528a18 ("binderfs: fix use-after-free in binder_devices") Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> Acked-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20250517170957.1317876-1-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.46.0) at 2026-05-05 17:56:58 +0000