kernel/linux.git/drivers/android, branch v6.19.11

rust_binder: call set_notification_done() without proc lock

2026-03-19T15:15:01+00:00

commit 2e303f0febb65a434040774b793ba8356698802b upstream. Consider the following sequence of events on a death listener: 1. The remote process dies and sends a BR_DEAD_BINDER message. 2. The local process invokes the BC_CLEAR_DEATH_NOTIFICATION command. 3. The local process then invokes the BC_DEAD_BINDER_DONE. Then, the kernel will reply to the BC_DEAD_BINDER_DONE command with a BR_CLEAR_DEATH_NOTIFICATION_DONE reply using push_work_if_looper(). However, this can result in a deadlock if the current thread is not a looper. This is because dead_binder_done() still holds the proc lock during set_notification_done(), which called push_work_if_looper(). Normally, push_work_if_looper() takes the thread lock, which is fine to take under the proc lock. But if the current thread is not a looper, then it falls back to delivering the reply to the process work queue, which involves taking the proc lock. Since the proc lock is already held, this is a deadlock. Fix this by releasing the proc lock during set_notification_done(). It was not intentional that it was held during that function to begin with. I don't think this ever happens in Android because BC_DEAD_BINDER_DONE is only invoked in response to BR_DEAD_BINDER messages, and the kernel always delivers BR_DEAD_BINDER to a looper. So there's no scenario where Android userspace will call BC_DEAD_BINDER_DONE on a non-looper thread. Cc: stable Fixes: eafedbc7c050 ("rust_binder: add Rust Binder driver") Reported-by: syzbot+c8287e65a57a89e7fb72@syzkaller.appspotmail.com Tested-by: syzbot+c8287e65a57a89e7fb72@syzkaller.appspotmail.com Signed-off-by: Alice Ryhl Reviewed-by: Gary Guo Reviewed-by: Andreas Hindborg Link: https://patch.msgid.link/20260224-binder-dead-binder-done-proc-lock-v1-1-bbe1b8a6e74a@google.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

rust_binder: avoid reading the written value in offsets array

2026-03-19T15:15:01+00:00

commit 4cb9e13fec0de7c942f5f927469beb8e48ddd20f upstream. When sending a transaction, its offsets array is first copied into the target proc's vma, and then the values are read back from there. This is normally fine because the vma is a read-only mapping, so the target process cannot change the value under us. However, if the target process somehow gains the ability to write to its own vma, it could change the offset before it's read back, causing the kernel to misinterpret what the sender meant. If the sender happens to send a payload with a specific shape, this could in the worst case lead to the receiver being able to privilege escalate into the sender. The intent is that gaining the ability to change the read-only vma of your own process should not be exploitable, so remove this TOCTOU read even though it's unexploitable without another Binder bug. Cc: stable Fixes: eafedbc7c050 ("rust_binder: add Rust Binder driver") Reported-by: Jann Horn Reviewed-by: Jann Horn Signed-off-by: Alice Ryhl Acked-by: Liam R. Howlett Link: https://patch.msgid.link/20260218-binder-vma-check-v2-2-60f9d695a990@google.com Signed-off-by: Greg Kroah-Hartman

rust_binder: check ownership before using vma

2026-03-19T15:15:01+00:00

commit 8ef2c15aeae07647f530d30f6daaf79eb801bcd1 upstream. When installing missing pages (or zapping them), Rust Binder will look up the vma in the mm by address, and then call vm_insert_page (or zap_page_range_single). However, if the vma is closed and replaced with a different vma at the same address, this can lead to Rust Binder installing pages into the wrong vma. By installing the page into a writable vma, it becomes possible to write to your own binder pages, which are normally read-only. Although you're not supposed to be able to write to those pages, the intent behind the design of Rust Binder is that even if you get that ability, it should not lead to anything bad. Unfortunately, due to another bug, that is not the case. To fix this, store a pointer in vm_private_data and check that the vma returned by vma_lookup() has the right vm_ops and vm_private_data before trying to use the vma. This should ensure that Rust Binder will refuse to interact with any other VMA. The plan is to introduce more vma abstractions to avoid this unsafe access to vm_ops and vm_private_data, but for now let's start with the simplest possible fix. C Binder performs the same check in a slightly different way: it provides a vm_ops->close that sets a boolean to true, then checks that boolean after calling vma_lookup(), but this is more fragile than the solution in this patch. (We probably still want to do both, but the vm_ops->close callback will be added later as part of the follow-up vma API changes.) It's still possible to remap the vma so that pages appear in the right vma, but at the wrong offset, but this is a separate issue and will be fixed when Rust Binder gets a vm_ops->close callback. Cc: stable Fixes: eafedbc7c050 ("rust_binder: add Rust Binder driver") Reported-by: Jann Horn Reviewed-by: Jann Horn Signed-off-by: Alice Ryhl Acked-by: Danilo Krummrich Acked-by: Liam R. Howlett Link: https://patch.msgid.link/20260218-binder-vma-check-v2-1-60f9d695a990@google.com Signed-off-by: Greg Kroah-Hartman

rust_binder: fix oneway spam detection

2026-03-19T15:15:00+00:00

commit 4fc87c240b8f30e22b7ebaae29d57105589e1c0b upstream. The spam detection logic in TreeRange was executed before the current request was inserted into the tree. So the new request was not being factored in the spam calculation. Fix this by moving the logic after the new range has been inserted. Also, the detection logic for ArrayRange was missing altogether which meant large spamming transactions could get away without being detected. Fix this by implementing an equivalent low_oneway_space() in ArrayRange. Note that I looked into centralizing this logic in RangeAllocator but iterating through 'state' and 'size' got a bit too complicated (for me) and I abandoned this effort. Cc: stable Cc: Alice Ryhl Fixes: eafedbc7c050 ("rust_binder: add Rust Binder driver") Signed-off-by: Carlos Llamas Reviewed-by: Alice Ryhl Link: https://patch.msgid.link/20260210232949.3770644-1-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman

binder: don't use %pK through printk

2026-03-04T12:20:42+00:00

[ Upstream commit 56d21267663bad91e8b10121224ec46366a7937e ] In the past %pK was preferable to %p as it would not leak raw pointer values into the kernel log. Since commit ad67b74d2469 ("printk: hash addresses printed with %p") the regular %p has been improved to avoid this issue. Furthermore, restricted pointers ("%pK") were never meant to be used through printk(). They can still unintentionally leak raw pointers or acquire sleeping locks in atomic contexts. Switch to the regular pointer formatting which is safer and easier to reason about. There are still a few users of %pK left, but these use it through seq_file, for which its usage is safe. Signed-off-by: Thomas Weißschuh Acked-by: Carlos Llamas Reviewed-by: Alice Ryhl Link: https://patch.msgid.link/20260107-restricted-pointers-binder-v1-1-181018bf3812@linutronix.de Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

rust_binder: Fix build failure if !CONFIG_COMPAT

2026-03-04T12:19:22+00:00

commit 174e2a339bf731e080ced67c215ad609a677560b upstream. The bindgen utility cannot handle "#define compat_ptr_ioctl NULL" in the C header, so we need to handle this case on our own. Simply skip this field in the initializer when !CONFIG_COMPAT as the SAFETY comment above this initializer implies this is allowed. Reported-by: Miguel Ojeda Closes: https://lore.kernel.org/all/CANiq72mrVzqXnAV=Hy2XBOonLHA6YQgH-ckZoc_h0VBvTGK8rA@mail.gmail.com/ Signed-off-by: Xi Ruoyao Reviewed-by: Alice Ryhl Link: https://patch.msgid.link/20251209125029.1117897-1-xry111@xry111.site Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

Merge tag 'char-misc-6.19-final' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2026-02-07T17:27:57+00:00

Pull binder fixes from Greg KH: "Here are some small, last-minute binder C and Rust driver fixes for reported issues. They include a number of fixes for reported crashes and other problems. All of these have been in linux-next this week, and longer" * tag 'char-misc-6.19-final' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: binderfs: fix ida_alloc_max() upper bound rust_binderfs: fix ida_alloc_max() upper bound binder: fix BR_FROZEN_REPLY error log rust_binder: add additional alignment checks binder: fix UAF in binder_netlink_report() rust_binder: correctly handle FDA objects of length zero

rust_binderfs: fix a dentry leak

2026-02-05T18:52:16+00:00

Parallel to binderfs patches - 02da8d2c0965 "binderfs_binder_ctl_create(): kill a bogus check" and the bit of b89aa544821d "convert binderfs" that got lost when making 4433d8e25d73 "convert rust_binderfs"; the former is a cleanup, the latter is about marking /binder-control persistent, so that it would be taken out on umount. Fixes: 4433d8e25d73 ("convert rust_binderfs") Acked-by: Alice Ryhl Acked-by: Christian Brauner Signed-off-by: Al Viro

binderfs: fix ida_alloc_max() upper bound

2026-02-03T11:59:07+00:00

The 'max' argument of ida_alloc_max() takes the maximum valid ID and not the "count". Using an ID of BINDERFS_MAX_MINOR (1 << 20) for dev->minor would exceed the limits of minor numbers (20-bits). Fix this off-by-one error by subtracting 1 from the 'max'. Cc: stable@vger.kernel.org Fixes: 3ad20fe393b3 ("binder: implement binderfs") Signed-off-by: Carlos Llamas Link: https://patch.msgid.link/20260127235545.2307876-2-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman

rust_binderfs: fix ida_alloc_max() upper bound

2026-02-03T11:59:06+00:00

The 'max' argument of ida_alloc_max() takes the maximum valid ID and not the "count". Using an ID of BINDERFS_MAX_MINOR (1 << 20) for dev->minor would exceed the limits of minor numbers (20-bits). Fix this off-by-one error by subtracting 1 from the 'max'. Cc: stable@vger.kernel.org Fixes: eafedbc7c050 ("rust_binder: add Rust Binder driver") Reported-by: kernel test robot Closes: https://lore.kernel.org/r/202512181203.IOv6IChH-lkp@intel.com/ Signed-off-by: Carlos Llamas Reviewed-by: Alice Ryhl Link: https://patch.msgid.link/20260127235545.2307876-1-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman