kernel/linux.git/drivers/android, branch v6.6.27

binder: signal epoll threads of self-work

2024-02-23T08:25:04+00:00

commit 97830f3c3088638ff90b20dfba2eb4d487bf14d7 upstream. In (e)poll mode, threads often depend on I/O events to determine when data is ready for consumption. Within binder, a thread may initiate a command via BINDER_WRITE_READ without a read buffer and then make use of epoll_wait() or similar to consume any responses afterwards. It is then crucial that epoll threads are signaled via wakeup when they queue their own work. Otherwise, they risk waiting indefinitely for an event leaving their work unhandled. What is worse, subsequent commands won't trigger a wakeup either as the thread has pending work. Fixes: 457b9a6f09f0 ("Staging: android: add binder driver") Cc: Arve Hjønnevåg Cc: Martijn Coenen Cc: Alice Ryhl Cc: Steven Moreland Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Carlos Llamas Link: https://lore.kernel.org/r/20240131215347.1808751-1-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

binder: fix race between mmput() and do_exit()

2024-01-25T23:35:42+00:00

commit 9a9ab0d963621d9d12199df9817e66982582d5a5 upstream. Task A calls binder_update_page_range() to allocate and insert pages on a remote address space from Task B. For this, Task A pins the remote mm via mmget_not_zero() first. This can race with Task B do_exit() and the final mmput() refcount decrement will come from Task A. Task A | Task B ------------------+------------------ mmget_not_zero() | | do_exit() | exit_mm() | mmput() mmput() | exit_mmap() | remove_vma() | fput() | In this case, the work of ____fput() from Task B is queued up in Task A as TWA_RESUME. So in theory, Task A returns to userspace and the cleanup work gets executed. However, Task A instead sleep, waiting for a reply from Task B that never comes (it's dead). This means the binder_deferred_release() is blocked until an unrelated binder event forces Task A to go back to userspace. All the associated death notifications will also be delayed until then. In order to fix this use mmput_async() that will schedule the work in the corresponding mm->async_put_work WQ instead of Task A. Fixes: 457b9a6f09f0 ("Staging: android: add binder driver") Reviewed-by: Alice Ryhl Signed-off-by: Carlos Llamas Link: https://lore.kernel.org/r/20231201172212.1813387-4-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman

binder: fix unused alloc->free_async_space

2024-01-25T23:35:41+00:00

commit c6d05e0762ab276102246d24affd1e116a46aa0c upstream. Each transaction is associated with a 'struct binder_buffer' that stores the metadata about its buffer area. Since commit 74310e06be4d ("android: binder: Move buffer out of area shared with user space") this struct is no longer embedded within the buffer itself but is instead allocated on the heap to prevent userspace access to this driver-exclusive info. Unfortunately, the space of this struct is still being accounted for in the total buffer size calculation, specifically for async transactions. This results in an additional 104 bytes added to every async buffer request, and this area is never used. This wasted space can be substantial. If we consider the maximum mmap buffer space of SZ_4M, the driver will reserve half of it for async transactions, or 0x200000. This area should, in theory, accommodate up to 262,144 buffers of the minimum 8-byte size. However, after adding the extra 'sizeof(struct binder_buffer)', the total number of buffers drops to only 18,724, which is a sad 7.14% of the actual capacity. This patch fixes the buffer size calculation to enable the utilization of the entire async buffer space. This is expected to reduce the number of -ENOSPC errors that are seen on the field. Fixes: 74310e06be4d ("android: binder: Move buffer out of area shared with user space") Signed-off-by: Carlos Llamas Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20231201172212.1813387-6-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

binder: fix async space check for 0-sized buffers

2024-01-25T23:35:41+00:00

commit 3091c21d3e9322428691ce0b7a0cfa9c0b239eeb upstream. Move the padding of 0-sized buffers to an earlier stage to account for this round up during the alloc->free_async_space check. Fixes: 74310e06be4d ("android: binder: Move buffer out of area shared with user space") Reviewed-by: Alice Ryhl Signed-off-by: Carlos Llamas Link: https://lore.kernel.org/r/20231201172212.1813387-5-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman

binder: fix comment on binder_alloc_new_buf() return value

2024-01-20T10:51:48+00:00

commit e1090371e02b601cbfcea175c2a6cc7c955fa830 upstream. Update the comments of binder_alloc_new_buf() to reflect that the return value of the function is now ERR_PTR(-errno) on failure. No functional changes in this patch. Cc: stable@vger.kernel.org Fixes: 57ada2fb2250 ("binder: add log information for binder transaction failures") Reviewed-by: Alice Ryhl Signed-off-by: Carlos Llamas Link: https://lore.kernel.org/r/20231201172212.1813387-8-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman

binder: fix trivial typo of binder_free_buf_locked()

2024-01-20T10:51:48+00:00

commit 122a3c1cb0ff304c2b8934584fcfea4edb2fe5e3 upstream. Fix minor misspelling of the function in the comment section. No functional changes in this patch. Cc: stable@vger.kernel.org Fixes: 0f966cba95c7 ("binder: add flag to clear buffer on txn complete") Reviewed-by: Alice Ryhl Signed-off-by: Carlos Llamas Link: https://lore.kernel.org/r/20231201172212.1813387-7-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman

binder: fix use-after-free in shinker's callback

2024-01-20T10:51:48+00:00

commit 3f489c2067c5824528212b0fc18b28d51332d906 upstream. The mmap read lock is used during the shrinker's callback, which means that using alloc->vma pointer isn't safe as it can race with munmap(). As of commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") the mmap lock is downgraded after the vma has been isolated. I was able to reproduce this issue by manually adding some delays and triggering page reclaiming through the shrinker's debug sysfs. The following KASAN report confirms the UAF: ================================================================== BUG: KASAN: slab-use-after-free in zap_page_range_single+0x470/0x4b8 Read of size 8 at addr ffff356ed50e50f0 by task bash/478 CPU: 1 PID: 478 Comm: bash Not tainted 6.6.0-rc5-00055-g1c8b86a3799f-dirty #70 Hardware name: linux,dummy-virt (DT) Call trace: zap_page_range_single+0x470/0x4b8 binder_alloc_free_page+0x608/0xadc __list_lru_walk_one+0x130/0x3b0 list_lru_walk_node+0xc4/0x22c binder_shrink_scan+0x108/0x1dc shrinker_debugfs_scan_write+0x2b4/0x500 full_proxy_write+0xd4/0x140 vfs_write+0x1ac/0x758 ksys_write+0xf0/0x1dc __arm64_sys_write+0x6c/0x9c Allocated by task 492: kmem_cache_alloc+0x130/0x368 vm_area_alloc+0x2c/0x190 mmap_region+0x258/0x18bc do_mmap+0x694/0xa60 vm_mmap_pgoff+0x170/0x29c ksys_mmap_pgoff+0x290/0x3a0 __arm64_sys_mmap+0xcc/0x144 Freed by task 491: kmem_cache_free+0x17c/0x3c8 vm_area_free_rcu_cb+0x74/0x98 rcu_core+0xa38/0x26d4 rcu_core_si+0x10/0x1c __do_softirq+0x2fc/0xd24 Last potentially related work creation: __call_rcu_common.constprop.0+0x6c/0xba0 call_rcu+0x10/0x1c vm_area_free+0x18/0x24 remove_vma+0xe4/0x118 do_vmi_align_munmap.isra.0+0x718/0xb5c do_vmi_munmap+0xdc/0x1fc __vm_munmap+0x10c/0x278 __arm64_sys_munmap+0x58/0x7c Fix this issue by performing instead a vma_lookup() which will fail to find the vma that was isolated before the mmap lock downgrade. Note that this option has better performance than upgrading to a mmap write lock which would increase contention. Plus, mmap_write_trylock() has been recently removed anyway. Fixes: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") Cc: stable@vger.kernel.org Cc: Liam Howlett Cc: Minchan Kim Reviewed-by: Alice Ryhl Signed-off-by: Carlos Llamas Link: https://lore.kernel.org/r/20231201172212.1813387-3-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman

binder: use EPOLLERR from eventpoll.h

2024-01-20T10:51:48+00:00

commit 6ac061db9c58ca5b9270b1b3940d2464fb3ff183 upstream. Use EPOLLERR instead of POLLERR to make sure it is cast to the correct __poll_t type. This fixes the following sparse issue: drivers/android/binder.c:5030:24: warning: incorrect type in return expression (different base types) drivers/android/binder.c:5030:24: expected restricted __poll_t drivers/android/binder.c:5030:24: got int Fixes: f88982679f54 ("binder: check for binder_thread allocation failure in binder_poll()") Cc: stable@vger.kernel.org Cc: Eric Biggers Reviewed-by: Alice Ryhl Signed-off-by: Carlos Llamas Link: https://lore.kernel.org/r/20231201172212.1813387-2-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman

binder: fix memory leaks of spam and pending work

2023-10-05T10:48:08+00:00

A transaction complete work is allocated and queued for each transaction. Under certain conditions the work->type might be marked as BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT to notify userspace about potential spamming threads or as BINDER_WORK_TRANSACTION_PENDING when the target is currently frozen. However, these work types are not being handled in binder_release_work() so they will leak during a cleanup. This was reported by syzkaller with the following kmemleak dump: BUG: memory leak unreferenced object 0xffff88810e2d6de0 (size 32): comm "syz-executor338", pid 5046, jiffies 4294968230 (age 13.590s) hex dump (first 32 bytes): e0 6d 2d 0e 81 88 ff ff e0 6d 2d 0e 81 88 ff ff .m-......m-..... 04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] kmalloc_trace+0x25/0x90 mm/slab_common.c:1114 [] kmalloc include/linux/slab.h:599 [inline] [] kzalloc include/linux/slab.h:720 [inline] [] binder_transaction+0x573/0x4050 drivers/android/binder.c:3152 [] binder_thread_write+0x6b5/0x1860 drivers/android/binder.c:4010 [] binder_ioctl_write_read drivers/android/binder.c:5066 [inline] [] binder_ioctl+0x1b2c/0x3cf0 drivers/android/binder.c:5352 [] vfs_ioctl fs/ioctl.c:51 [inline] [] __do_sys_ioctl fs/ioctl.c:871 [inline] [] __se_sys_ioctl fs/ioctl.c:857 [inline] [] __x64_sys_ioctl+0xf2/0x140 fs/ioctl.c:857 [] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 [] entry_SYSCALL_64_after_hwframe+0x63/0xcd Fix the leaks by kfreeing these work types in binder_release_work() and handle them as a BINDER_WORK_TRANSACTION_COMPLETE cleanup. Cc: stable@vger.kernel.org Fixes: 0567461a7a6e ("binder: return pending info for frozen async txns") Fixes: a7dc1e6f99df ("binder: tell userspace to dump current backtrace when detected oneway spamming") Reported-by: syzbot+7f10c1653e35933c0f1e@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=7f10c1653e35933c0f1e Suggested-by: Alice Ryhl Signed-off-by: Carlos Llamas Reviewed-by: Alice Ryhl Acked-by: Todd Kjos Link: https://lore.kernel.org/r/20230922175138.230331-1-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman

Merge tag 'char-misc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2023-09-01T16:53:54+00:00

Pull char/misc driver updates from Greg KH: "Here is the big set of char/misc and other small driver subsystem changes for 6.6-rc1. Stuff all over the place here, lots of driver updates and changes and new additions. Short summary is: - new IIO drivers and updates - Interconnect driver updates - fpga driver updates and additions - fsi driver updates - mei driver updates - coresight driver updates - nvmem driver updates - counter driver updates - lots of smaller misc and char driver updates and additions All of these have been in linux-next for a long time with no reported problems" * tag 'char-misc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (267 commits) nvmem: core: Notify when a new layout is registered nvmem: core: Do not open-code existing functions nvmem: core: Return NULL when no nvmem layout is found nvmem: core: Create all cells before adding the nvmem device nvmem: u-boot-env:: Replace zero-length array with DECLARE_FLEX_ARRAY() helper nvmem: sec-qfprom: Add Qualcomm secure QFPROM support dt-bindings: nvmem: sec-qfprom: Add bindings for secure qfprom dt-bindings: nvmem: Add compatible for QCM2290 nvmem: Kconfig: Fix typo "drive" -> "driver" nvmem: Explicitly include correct DT includes nvmem: add new NXP QorIQ eFuse driver dt-bindings: nvmem: Add t1023-sfp efuse support dt-bindings: nvmem: qfprom: Add compatible for MSM8226 nvmem: uniphier: Use devm_platform_get_and_ioremap_resource() nvmem: qfprom: do some cleanup nvmem: stm32-romem: Use devm_platform_get_and_ioremap_resource() nvmem: rockchip-efuse: Use devm_platform_get_and_ioremap_resource() nvmem: meson-mx-efuse: Convert to devm_platform_ioremap_resource() nvmem: lpc18xx_otp: Convert to devm_platform_ioremap_resource() nvmem: brcm_nvram: Use devm_platform_get_and_ioremap_resource() ...