linux-next.git/drivers/android, branch master

rust_binder: clear freeze listener on node removal

2026-07-03T11:54:10+00:00

Generally userspace is supposed to explicitly clear freeze listeners before they drop the refcount on the node ref to zero, but there's nothing forcing that. Currently, in this scenario the freeze listener remains in the freeze_listeners rbtree and in the remote node's freeze listener list, even though the ref for which the listener is registered is gone. This could potentially lead to a memory leak due to a refcount cycle. Thus, remove the freeze listener in this scenario. Cc: stable Fixes: eafedbc7c050 ("rust_binder: add Rust Binder driver") Signed-off-by: Alice Ryhl Link: https://patch.msgid.link/20260703-remove-freeze-on-remove-node-v3-1-6e0c4547af46@google.com Signed-off-by: Greg Kroah-Hartman

rust_binder: reject context manager self-transaction

2026-07-03T10:28:43+00:00

Rust binder resolved handle 0 to the context manager node, but it does not reject the case where the caller owns the same node. The C binder driver rejects transactions from the context-manager process to handle 0 after resolving the target node. Match that behavior in Rust Binder by rejecting handle 0 transactions when the resolved context-manager node is owned by the calling process. This applies to both synchronous and oneway transactions because both paths resolve the target through Process::get_transaction_node(). Cc: stable Fixes: eafedbc7c050 ("rust_binder: add Rust Binder driver") Signed-off-by: Keshav Verma Reviewed-by: Alice Ryhl Link: https://patch.msgid.link/20260625103957.730-1-iganschel@gmail.com Signed-off-by: Greg Kroah-Hartman

rust_binder: use a u64 stride when cleaning up the offsets array

2026-07-03T10:28:28+00:00

Allocation's Drop walks the offsets array (binder_size_t = u64 entries), cleaning up the objects, but it used usize instead of u64 for both the stride and the per-entry read. On 64-bit kernels (usize == u64) this is harmless, but on 32-bit kernels it walks the 8-byte entries in 4-byte steps, iterating an N-entry array 2N times, and reads the always-zero high word as offset 0, cleaning up the object at offset 0 N extra times. As a result the referenced node or handle ends up with a lower reference count than it actually has (a refcount over-decrement), and binder's reference accounting is corrupted; for example, the owner can be notified of a strong reference release (BR_RELEASE) even though references still remain. Change the stride to u64, and read each entry as a u64, narrowing it to usize with try_into(). On 32-bit ARM, when this over-decrement would drive a count below zero, the driver's existing refcount guard refuses it and fires: rust_binder: Failure: refcount underflow! Cc: stable Fixes: eafedbc7c050 ("rust_binder: add Rust Binder driver") Signed-off-by: Hyunwoo Kim Acked-by: Carlos Llamas Reviewed-by: Alice Ryhl Link: https://patch.msgid.link/ahw3tFhLz9bMMJAO@v4bel Signed-off-by: Greg Kroah-Hartman

binder: fix UAF in binder_free_transaction()

2026-07-03T10:28:12+00:00

In binder_free_transaction(), the t->to_proc is read under the t->lock. However, once the t->lock is dropped, the to_proc can die in parallel. This leads to a use-after-free error when we attempt to acquire its inner lock right afterwards: ================================================================== BUG: KASAN: slab-use-after-free in _raw_spin_lock+0xe4/0x1a0 Write of size 4 at addr ffff00001125da70 by task B/672 CPU: 20 UID: 0 PID: 672 Comm: B Not tainted 7.1.0-rc6-00284-g8e65320d91cd #4 PREEMPT Hardware name: linux,dummy-virt (DT) Call trace: _raw_spin_lock+0xe4/0x1a0 binder_free_transaction+0x8c/0x320 binder_send_failed_reply+0x21c/0x2f8 binder_thread_release+0x488/0x7e0 binder_ioctl+0x12c0/0x29a0 [...] Allocated by task 675: __kmalloc_cache_noprof+0x174/0x444 binder_open+0x118/0xb70 do_dentry_open+0x374/0x1040 vfs_open+0x58/0x3bc [...] Freed by task 212: __kasan_slab_free+0x58/0x80 kfree+0x1a0/0x4a4 binder_proc_dec_tmpref+0x32c/0x5e0 binder_deferred_func+0xc48/0x104c process_one_work+0x53c/0xbc0 [...] ================================================================== To prevent this, pin the target thread (t->to_thread) to guarantee the target process remains alive. Undelivered transactions without a target thread are already safe, as the target process can only be the current context in those paths. Cc: stable Reported-by: Alice Ryhl Closes: https://lore.kernel.org/all/aikJKVuny_eOivwN@google.com/ Fixes: a370003cc301 ("binder: fix possible UAF when freeing buffer") Signed-off-by: Carlos Llamas Reviewed-by: Alice Ryhl Link: https://patch.msgid.link/20260619185233.2194678-2-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman

binder: fix UAF in binder_thread_release()

2026-07-03T10:28:08+00:00

When a thread exits, binder_thread_release() walks its transaction stack to clear the t->from and t->to_proc that correspond with the exiting thread. However, a process dying in parallel might attempt to kfree some of these transactions. And if one of them has no associated t->to_proc, the t->to_proc->inner_lock will not be acquired. This means that transaction accesses in binder_thread_release() after t->to_proc has been cleared might race with binder_free_transaction() and cause a use-after-free error as reported by KASAN: ================================================================== BUG: KASAN: slab-use-after-free in binder_thread_release+0x5d0/0x798 Write of size 8 at addr ffff000016627500 by task X/715 CPU: 17 UID: 0 PID: 715 Comm: X Not tainted 7.1.0-rc5-00149-g8fde5d1d47f6 #30 PREEMPT Hardware name: linux,dummy-virt (DT) Call trace: binder_thread_release+0x5d0/0x798 binder_ioctl+0x12c0/0x299c [...] Allocated by task 717 on cpu 18 at 67.267803s: __kasan_kmalloc+0xa0/0xbc __kmalloc_cache_noprof+0x174/0x444 binder_transaction+0x554/0x8150 binder_thread_write+0xa30/0x4354 binder_ioctl+0x20f0/0x299c [...] Freed by task 202 on cpu 18 at 90.416221s: __kasan_slab_free+0x58/0x80 kfree+0x1a0/0x4a4 binder_free_transaction+0x150/0x294 binder_send_failed_reply+0x398/0x6d8 binder_release_work+0x3e4/0x4ec binder_deferred_func+0xbd8/0x104c [...] ================================================================== In order to avoid this, make sure that binder_free_transaction() reads the t->to_proc under the transaction lock. This will serialize the transaction release with the accesses in binder_thread_release(). Plus, it matches the documented locking rules for @to_proc. Cc: stable Fixes: 7a4408c6bd3e ("binder: make sure accesses to proc/thread are safe") Reviewed-by: Alice Ryhl Signed-off-by: Carlos Llamas Link: https://patch.msgid.link/20260619185233.2194678-1-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman

rust_binder: synchronize Rust Binder stats with freeze commands

2026-07-03T10:27:38+00:00

Rust Binder stats use BC_COUNT and BR_COUNT to size the command and return counters, and use event string tables when printing debug statistics. The Binder protocol includes freeze-related commands and return codes, but the Rust Binder statistics code was not updated to cover them. As a result, those commands and return codes are not accounted for or printed by the stats debug output. Update the counts and event string tables so these commands and return codes are included in the debug statistics output. Fixes: eafedbc7c050 ("rust_binder: add Rust Binder driver") Cc: stable Acked-by: Carlos Llamas Reviewed-by: Alice Ryhl Signed-off-by: Keshav Verma Link: https://patch.msgid.link/20260615211743.734-1-iganschel@gmail.com Signed-off-by: Greg Kroah-Hartman

binder: cache secctx size before release zeroes it

2026-07-03T10:26:32+00:00

binder_transaction() bounds the scatter-gather buffer area with sg_buf_end_offset and subtracts the aligned LSM context size because the secctx is written at the tail of that area. The subtraction reads lsmctx.len, but that field has already been cleared by the time the line runs: security_secid_to_secctx(secid, &lsmctx) /* lsmctx.len set */ lsmctx_aligned_size = ALIGN(lsmctx.len, sizeof(u64)) extra_buffers_size += lsmctx_aligned_size ... security_release_secctx(&lsmctx) /* memset zeroes len */ ... sg_buf_end_offset = sg_buf_offset + extra_buffers_size - ALIGN(lsmctx.len, sizeof(u64)) /* ALIGN(0,8) */ security_release_secctx() does memset(cp, 0, sizeof(*cp)), so lsmctx.len reads back as 0 and the subtraction contributes nothing, leaving sg_buf_end_offset too large by the aligned secctx size on every transaction to a txn_security_ctx node. Each BINDER_TYPE_PTR object then derives buf_left = sg_buf_end_offset - sg_buf_offset as the sole upper bound on its copy, so the inflated end offset lets the copy run into the bytes that already hold the secctx. The aligned size must therefore be cached before release rather than re-read from the now-cleared field. Fix by caching it in lsmctx_aligned_size at function scope when it is first computed and subtracting lsmctx_aligned_size instead of re-reading lsmctx.len after release. Reuse the same value for the earlier buf_offset computation. Fixes: 6fba89813ccf ("lsm: ensure the correct LSM context releaser") Cc: stable Assisted-by: kres:claude-opus-4-8 Signed-off-by: Chris Mason Reviewed-by: Alice Ryhl Acked-by: Carlos Llamas Link: https://patch.msgid.link/20260603174506.1957278-1-clm@meta.com Signed-off-by: Greg Kroah-Hartman

rust_binder: fix BINDER_GET_EXTENDED_ERROR

2026-07-03T10:18:59+00:00

This code currently copies the ExtendedError struct to the stack, modifies the copy, and then doesn't modify the original. Thus, fix it. Furthermore, errors when replying must be delivered directly to the remote thread, so update deliver_reply() to take an extended error argument. Cc: stable Fixes: eafedbc7c050 ("rust_binder: add Rust Binder driver") Signed-off-by: Alice Ryhl Acked-by: Carlos Llamas Link: https://patch.msgid.link/20260605-set-extended-error-v3-1-d60b69a75f97@google.com Signed-off-by: Greg Kroah-Hartman

Merge tag 'v7.1-rc6' into char-misc-next

2026-06-01T16:10:34+00:00

We need the char/misc/iio fixes in here as well. Signed-off-by: Greg Kroah-Hartman

binder: Use LIST_HEAD() to initialize on stack list head

2026-05-23T11:47:32+00:00

Use LIST_HEAD to initialize on stack list head. No intentional functional impact. Change generated with below coccinelle script: @@ identifier name; @@ - struct list_head name; + LIST_HEAD(name); ... when != name - INIT_LIST_HEAD(&name); Signed-off-by: Jisheng Zhang Link: https://patch.msgid.link/20260519055623.13142-1-jszhang@kernel.org Signed-off-by: Greg Kroah-Hartman