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2020-12-16Merge branch 'exec-for-v5.11' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull execve updates from Eric Biederman: "This set of changes ultimately fixes the interaction of posix file lock and exec. Fundamentally most of the change is just moving where unshare_files is called during exec, and tweaking the users of files_struct so that the count of files_struct is not unnecessarily played with. Along the way fcheck and related helpers were renamed to more accurately reflect what they do. There were also many other small changes that fell out, as this is the first time in a long time much of this code has been touched. Benchmarks haven't turned up any practical issues but Al Viro has observed a possibility for a lot of pounding on task_lock. So I have some changes in progress to convert put_files_struct to always rcu free files_struct. That wasn't ready for the merge window so that will have to wait until next time" * 'exec-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits) exec: Move io_uring_task_cancel after the point of no return coredump: Document coredump code exclusively used by cell spufs file: Remove get_files_struct file: Rename __close_fd_get_file close_fd_get_file file: Replace ksys_close with close_fd file: Rename __close_fd to close_fd and remove the files parameter file: Merge __alloc_fd into alloc_fd file: In f_dupfd read RLIMIT_NOFILE once. file: Merge __fd_install into fd_install proc/fd: In fdinfo seq_show don't use get_files_struct bpf/task_iter: In task_file_seq_get_next use task_lookup_next_fd_rcu proc/fd: In proc_readfd_common use task_lookup_next_fd_rcu file: Implement task_lookup_next_fd_rcu kcmp: In get_file_raw_ptr use task_lookup_fd_rcu proc/fd: In tid_fd_mode use task_lookup_fd_rcu file: Implement task_lookup_fd_rcu file: Rename fcheck lookup_fd_rcu file: Replace fcheck_files with files_lookup_fd_rcu file: Factor files_lookup_fd_locked out of fcheck_files file: Rename __fcheck_files to files_lookup_fd_raw ...
2020-12-10file: Rename __close_fd_get_file close_fd_get_fileEric W. Biederman1-1/+1
The function close_fd_get_file is explicitly a variant of __close_fd[1]. Now that __close_fd has been renamed close_fd, rename close_fd_get_file to be consistent with close_fd. When __alloc_fd, __close_fd and __fd_install were introduced the double underscore indicated that the function took a struct files_struct parameter. The function __close_fd_get_file never has so the naming has always been inconsistent. This just cleans things up so there are not any lingering mentions or references __close_fd left in the code. [1] 80cd795630d6 ("binder: fix use-after-free due to ksys_close() during fdget()") Link: https://lkml.kernel.org/r/20201120231441.29911-23-ebiederm@xmission.com Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-12-09binder: add flag to clear buffer on txn completeTodd Kjos1-0/+1
Add a per-transaction flag to indicate that the buffer must be cleared when the transaction is complete to prevent copies of sensitive data from being preserved in memory. Signed-off-by: Todd Kjos <tkjos@google.com> Link: https://lore.kernel.org/r/20201120233743.3617529-1-tkjos@google.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-11binder: add trace at free transaction.Frankie.Chang1-0/+18
Since the original trace_binder_transaction_received cannot precisely present the real finished time of transaction, adding a trace_binder_txn_latency_free at the point of free transaction may be more close to it. Signed-off-by: Frankie.Chang <Frankie.Chang@mediatek.com> Acked-by: Todd Kjos <tkjos@google.com> Link: https://lore.kernel.org/r/1605063764-12930-3-git-send-email-Frankie.Chang@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-11binder: move structs from core file to header fileFrankie.Chang1-406/+0
Moving all structs to header file makes module more extendable, and makes all these structs to be defined in the same file. Signed-off-by: Frankie.Chang <Frankie.Chang@mediatek.com> Acked-by: Todd Kjos <tkjos@google.com> Link: https://lore.kernel.org/r/1605063764-12930-2-git-send-email-Frankie.Chang@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-09binder: change error code from postive to negative in binder_transactionZhang Qilong1-1/+1
Depending on the context, the error return value here (extra_buffers_size < added_size) should be negative. Acked-by: Martijn Coenen <maco@android.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com> Link: https://lore.kernel.org/r/20201026110314.135481-1-zhangqilong3@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-09Android: binder: added a missing blank line after declarationAndrew Bridges1-0/+1
Fixed a coding style issue. Signed-off-by: Andrew Bridges <andrew@slova.app> Link: https://lore.kernel.org/r/20201027225655.650922-1-andrew@slova.app Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-18task_work: cleanup notification modesJens Axboe1-1/+1
A previous commit changed the notification mode from true/false to an int, allowing notify-no, notify-yes, or signal-notify. This was backwards compatible in the sense that any existing true/false user would translate to either 0 (on notification sent) or 1, the latter which mapped to TWA_RESUME. TWA_SIGNAL was assigned a value of 2. Clean this up properly, and define a proper enum for the notification mode. Now we have: - TWA_NONE. This is 0, same as before the original change, meaning no notification requested. - TWA_RESUME. This is 1, same as before the original change, meaning that we use TIF_NOTIFY_RESUME. - TWA_SIGNAL. This uses TIF_SIGPENDING/JOBCTL_TASK_WORK for the notification. Clean up all the callers, switching their 0/1/false/true to using the appropriate TWA_* mode for notifications. Fixes: e91b48162332 ("task_work: teach task_work_add() to do signal_wake_up()") Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-10binder: fix UAF when releasing todo listTodd Kjos1-25/+10
When releasing a thread todo list when tearing down a binder_proc, the following race was possible which could result in a use-after-free: 1. Thread 1: enter binder_release_work from binder_thread_release 2. Thread 2: binder_update_ref_for_handle() -> binder_dec_node_ilocked() 3. Thread 2: dec nodeA --> 0 (will free node) 4. Thread 1: ACQ inner_proc_lock 5. Thread 2: block on inner_proc_lock 6. Thread 1: dequeue work (BINDER_WORK_NODE, part of nodeA) 7. Thread 1: REL inner_proc_lock 8. Thread 2: ACQ inner_proc_lock 9. Thread 2: todo list cleanup, but work was already dequeued 10. Thread 2: free node 11. Thread 2: REL inner_proc_lock 12. Thread 1: deref w->type (UAF) The problem was that for a BINDER_WORK_NODE, the binder_work element must not be accessed after releasing the inner_proc_lock while processing the todo list elements since another thread might be handling a deref on the node containing the binder_work element leading to the node being freed. Signed-off-by: Todd Kjos <tkjos@google.com> Link: https://lore.kernel.org/r/20201009232455.4054810-1-tkjos@google.com Cc: <stable@vger.kernel.org> # 4.14, 4.19, 5.4, 5.8 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-05binder: simplify the return expression of binder_mmapLiu Shixin1-14/+4
Simplify the return expression. Acked-by: Martijn Coenen <maco@android.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Liu Shixin <liushixin2@huawei.com> Link: https://lore.kernel.org/r/20200929015216.1829946-1-liushixin2@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03binder: print warnings when detecting oneway spamming.Martijn Coenen1-1/+1
The most common cause of the binder transaction buffer filling up is a client rapidly firing oneway transactions into a process, before it has a chance to handle them. Yet the root cause of this is often hard to debug, because either the system or the app will stop, and by that time binder debug information we dump in bugreports is no longer relevant. This change warns as soon as a process dips below 80% of its oneway space (less than 100kB available in the configuration), when any one process is responsible for either more than 50 transactions, or more than 50% of the oneway space. Signed-off-by: Martijn Coenen <maco@android.com> Acked-by: Todd Kjos <tkjos@google.com> Link: https://lore.kernel.org/r/20200821122544.1277051-1-maco@android.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03binder: Remove bogus warning on failed same-process transactionJann Horn1-2/+0
While binder transactions with the same binder_proc as sender and recipient are forbidden, transactions with the same task_struct as sender and recipient are possible (even though currently there is a weird check in binder_transaction() that rejects them in the target==0 case). Therefore, task_struct identities can't be used to distinguish whether the caller is running in the context of the sender or the recipient. Since I see no easy way to make this WARN_ON() useful and correct, let's just remove it. Fixes: 44d8047f1d87 ("binder: use standard functions to allocate fds") Reported-by: syzbot+e113a0b970b7b3f394ba@syzkaller.appspotmail.com Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Acked-by: Todd Kjos <tkjos@google.com> Signed-off-by: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/r/20200806165359.2381483-1-jannh@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29drivers: android: Remove braces for a single statement if-else blockMrinal Pandey1-3/+2
Remove braces for both if and else block as suggested by checkpatch. Signed-off-by: Mrinal Pandey <mrinalmni@gmail.com> Link: https://lore.kernel.org/r/20200724131403.dahfhdwa3wirzkxj@mrinalpandey Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29drivers: android: Remove the use of else after returnMrinal Pandey1-2/+1
Remove the unnecessary else branch after return statement as suggested by checkpatch. Signed-off-by: Mrinal Pandey <mrinalmni@gmail.com> Link: https://lore.kernel.org/r/20200724131348.haz4ocxcferdcsgn@mrinalpandey Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29binder: Prevent context manager from incrementing ref 0Jann Horn1-1/+14
Binder is designed such that a binder_proc never has references to itself. If this rule is violated, memory corruption can occur when a process sends a transaction to itself; see e.g. <https://syzkaller.appspot.com/bug?extid=09e05aba06723a94d43d>. There is a remaining edgecase through which such a transaction-to-self can still occur from the context of a task with BINDER_SET_CONTEXT_MGR access: - task A opens /dev/binder twice, creating binder_proc instances P1 and P2 - P1 becomes context manager - P2 calls ACQUIRE on the magic handle 0, allocating index 0 in its handle table - P1 dies (by closing the /dev/binder fd and waiting a bit) - P2 becomes context manager - P2 calls ACQUIRE on the magic handle 0, allocating index 1 in its handle table [this triggers a warning: "binder: 1974:1974 tried to acquire reference to desc 0, got 1 instead"] - task B opens /dev/binder once, creating binder_proc instance P3 - P3 calls P2 (via magic handle 0) with (void*)1 as argument (two-way transaction) - P2 receives the handle and uses it to call P3 (two-way transaction) - P3 calls P2 (via magic handle 0) (two-way transaction) - P2 calls P2 (via handle 1) (two-way transaction) And then, if P2 does *NOT* accept the incoming transaction work, but instead closes the binder fd, we get a crash. Solve it by preventing the context manager from using ACQUIRE on ref 0. There shouldn't be any legitimate reason for the context manager to do that. Additionally, print a warning if someone manages to find another way to trigger a transaction-to-self bug in the future. Cc: stable@vger.kernel.org Fixes: 457b9a6f09f0 ("Staging: android: add binder driver") Acked-by: Todd Kjos <tkjos@google.com> Signed-off-by: Jann Horn <jannh@google.com> Reviewed-by: Martijn Coenen <maco@android.com> Link: https://lore.kernel.org/r/20200727120424.1627555-1-jannh@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-23binder: fix null deref of proc->contextTodd Kjos1-7/+7
The binder driver makes the assumption proc->context pointer is invariant after initialization (as documented in the kerneldoc header for struct proc). However, in commit f0fe2c0f050d ("binder: prevent UAF for binderfs devices II") proc->context is set to NULL during binder_deferred_release(). Another proc was in the middle of setting up a transaction to the dying process and crashed on a NULL pointer deref on "context" which is a local set to &proc->context: new_ref->data.desc = (node == context->binder_context_mgr_node) ? 0 : 1; Here's the stack: [ 5237.855435] Call trace: [ 5237.855441] binder_get_ref_for_node_olocked+0x100/0x2ec [ 5237.855446] binder_inc_ref_for_node+0x140/0x280 [ 5237.855451] binder_translate_binder+0x1d0/0x388 [ 5237.855456] binder_transaction+0x2228/0x3730 [ 5237.855461] binder_thread_write+0x640/0x25bc [ 5237.855466] binder_ioctl_write_read+0xb0/0x464 [ 5237.855471] binder_ioctl+0x30c/0x96c [ 5237.855477] do_vfs_ioctl+0x3e0/0x700 [ 5237.855482] __arm64_sys_ioctl+0x78/0xa4 [ 5237.855488] el0_svc_common+0xb4/0x194 [ 5237.855493] el0_svc_handler+0x74/0x98 [ 5237.855497] el0_svc+0x8/0xc The fix is to move the kfree of the binder_device to binder_free_proc() so the binder_device is freed when we know there are no references remaining on the binder_proc. Fixes: f0fe2c0f050d ("binder: prevent UAF for binderfs devices II") Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Todd Kjos <tkjos@google.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200622200715.114382-1-tkjos@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-03binder: prevent UAF for binderfs devices IIChristian Brauner1-3/+9
This is a necessary follow up to the first fix I proposed and we merged in 2669b8b0c79 ("binder: prevent UAF for binderfs devices"). I have been overly optimistic that the simple fix I proposed would work. But alas, ihold() + iput() won't work since the inodes won't survive the destruction of the superblock. So all we get with my prior fix is a different race with a tinier race-window but it doesn't solve the issue. Fwiw, the problem lies with generic_shutdown_super(). It even has this cozy Al-style comment: if (!list_empty(&sb->s_inodes)) { printk("VFS: Busy inodes after unmount of %s. " "Self-destruct in 5 seconds. Have a nice day...\n", sb->s_id); } On binder_release(), binder_defer_work(proc, BINDER_DEFERRED_RELEASE) is called which punts the actual cleanup operation to a workqueue. At some point, binder_deferred_func() will be called which will end up calling binder_deferred_release() which will retrieve and cleanup the binder_context attach to this struct binder_proc. If we trace back where this binder_context is attached to binder_proc we see that it is set in binder_open() and is taken from the struct binder_device it is associated with. This obviously assumes that the struct binder_device that context is attached to is _never_ freed. While that might be true for devtmpfs binder devices it is most certainly wrong for binderfs binder devices. So, assume binder_open() is called on a binderfs binder devices. We now stash away the struct binder_context associated with that struct binder_devices: proc->context = &binder_dev->context; /* binderfs stashes devices in i_private */ if (is_binderfs_device(nodp)) { binder_dev = nodp->i_private; info = nodp->i_sb->s_fs_info; binder_binderfs_dir_entry_proc = info->proc_log_dir; } else { . . . proc->context = &binder_dev->context; Now let's assume that the binderfs instance for that binder devices is shutdown via umount() and/or the mount namespace associated with it goes away. As long as there is still an fd open for that binderfs binder device things are fine. But let's assume we now close the last fd for that binderfs binder device. Now binder_release() is called and punts to the workqueue. Assume that the workqueue has quite a bit of stuff to do and doesn't get to cleaning up the struct binder_proc and the associated struct binder_context with it for that binderfs binder device right away. In the meantime, the VFS is killing the super block and is ultimately calling sb->evict_inode() which means it will call binderfs_evict_inode() which does: static void binderfs_evict_inode(struct inode *inode) { struct binder_device *device = inode->i_private; struct binderfs_info *info = BINDERFS_I(inode); clear_inode(inode); if (!S_ISCHR(inode->i_mode) || !device) return; mutex_lock(&binderfs_minors_mutex); --info->device_count; ida_free(&binderfs_minors, device->miscdev.minor); mutex_unlock(&binderfs_minors_mutex); kfree(device->context.name); kfree(device); } thereby freeing the struct binder_device including struct binder_context. Now the workqueue finally has time to get around to cleaning up struct binder_proc and is now trying to access the associate struct binder_context. Since it's already freed it will OOPs. Fix this by introducing a refounct on binder devices. This is an alternative fix to 51d8a7eca677 ("binder: prevent UAF read in print_binder_transaction_log_entry()"). Fixes: 3ad20fe393b3 ("binder: implement binderfs") Fixes: 2669b8b0c798 ("binder: prevent UAF for binderfs devices") Fixes: 03e2e07e3814 ("binder: Make transaction_log available in binderfs") Related : 51d8a7eca677 ("binder: prevent UAF read in print_binder_transaction_log_entry()") Cc: stable@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Acked-by: Todd Kjos <tkjos@google.com> Link: https://lore.kernel.org/r/20200303164340.670054-1-christian.brauner@ubuntu.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-03binder: prevent UAF for binderfs devicesChristian Brauner1-1/+4
On binder_release(), binder_defer_work(proc, BINDER_DEFERRED_RELEASE) is called which punts the actual cleanup operation to a workqueue. At some point, binder_deferred_func() will be called which will end up calling binder_deferred_release() which will retrieve and cleanup the binder_context attach to this struct binder_proc. If we trace back where this binder_context is attached to binder_proc we see that it is set in binder_open() and is taken from the struct binder_device it is associated with. This obviously assumes that the struct binder_device that context is attached to is _never_ freed. While that might be true for devtmpfs binder devices it is most certainly wrong for binderfs binder devices. So, assume binder_open() is called on a binderfs binder devices. We now stash away the struct binder_context associated with that struct binder_devices: proc->context = &binder_dev->context; /* binderfs stashes devices in i_private */ if (is_binderfs_device(nodp)) { binder_dev = nodp->i_private; info = nodp->i_sb->s_fs_info; binder_binderfs_dir_entry_proc = info->proc_log_dir; } else { . . . proc->context = &binder_dev->context; Now let's assume that the binderfs instance for that binder devices is shutdown via umount() and/or the mount namespace associated with it goes away. As long as there is still an fd open for that binderfs binder device things are fine. But let's assume we now close the last fd for that binderfs binder device. Now binder_release() is called and punts to the workqueue. Assume that the workqueue has quite a bit of stuff to do and doesn't get to cleaning up the struct binder_proc and the associated struct binder_context with it for that binderfs binder device right away. In the meantime, the VFS is killing the super block and is ultimately calling sb->evict_inode() which means it will call binderfs_evict_inode() which does: static void binderfs_evict_inode(struct inode *inode) { struct binder_device *device = inode->i_private; struct binderfs_info *info = BINDERFS_I(inode); clear_inode(inode); if (!S_ISCHR(inode->i_mode) || !device) return; mutex_lock(&binderfs_minors_mutex); --info->device_count; ida_free(&binderfs_minors, device->miscdev.minor); mutex_unlock(&binderfs_minors_mutex); kfree(device->context.name); kfree(device); } thereby freeing the struct binder_device including struct binder_context. Now the workqueue finally has time to get around to cleaning up struct binder_proc and is now trying to access the associate struct binder_context. Since it's already freed it will OOPs. Fix this by holding an additional reference to the inode that is only released once the workqueue is done cleaning up struct binder_proc. This is an easy alternative to introducing separate refcounting on struct binder_device which we can always do later if it becomes necessary. This is an alternative fix to 51d8a7eca677 ("binder: prevent UAF read in print_binder_transaction_log_entry()"). Fixes: 3ad20fe393b3 ("binder: implement binderfs") Fixes: 03e2e07e3814 ("binder: Make transaction_log available in binderfs") Related : 51d8a7eca677 ("binder: prevent UAF read in print_binder_transaction_log_entry()") Cc: stable@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Acked-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-30Merge tag 'for-5.6/io_uring-vfs-2020-01-29' of git://git.kernel.dk/linux-blockLinus Torvalds1-2/+4
Pull io_uring updates from Jens Axboe: - Support for various new opcodes (fallocate, openat, close, statx, fadvise, madvise, openat2, non-vectored read/write, send/recv, and epoll_ctl) - Faster ring quiesce for fileset updates - Optimizations for overflow condition checking - Support for max-sized clamping - Support for probing what opcodes are supported - Support for io-wq backend sharing between "sibling" rings - Support for registering personalities - Lots of little fixes and improvements * tag 'for-5.6/io_uring-vfs-2020-01-29' of git://git.kernel.dk/linux-block: (64 commits) io_uring: add support for epoll_ctl(2) eventpoll: support non-blocking do_epoll_ctl() calls eventpoll: abstract out epoll_ctl() handler io_uring: fix linked command file table usage io_uring: support using a registered personality for commands io_uring: allow registering credentials io_uring: add io-wq workqueue sharing io-wq: allow grabbing existing io-wq io_uring/io-wq: don't use static creds/mm assignments io-wq: make the io_wq ref counted io_uring: fix refcounting with batched allocations at OOM io_uring: add comment for drain_next io_uring: don't attempt to copy iovec for READ/WRITE io_uring: honor IOSQE_ASYNC for linked reqs io_uring: prep req when do IOSQE_ASYNC io_uring: use labeled array init in io_op_defs io_uring: optimise sqe-to-req flags translation io_uring: remove REQ_F_IO_DRAINED io_uring: file switch work needs to get flushed on exit io_uring: hide uring_fd in ctx ...
2020-01-22binder: fix log spam for existing debugfs file creation.Martin Fuzzey1-18/+19
Since commit 43e23b6c0b01 ("debugfs: log errors when something goes wrong") debugfs logs attempts to create existing files. However binder attempts to create multiple debugfs files with the same name when a single PID has multiple contexts, this leads to log spamming during an Android boot (17 such messages during boot on my system). Fix this by checking if we already know the PID and only create the debugfs entry for the first context per PID. Do the same thing for binderfs for symmetry. Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group> Acked-by: Todd Kjos <tkjos@google.com> Fixes: 43e23b6c0b01 ("debugfs: log errors when something goes wrong") Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/1578671054-5982-1-git-send-email-martin.fuzzey@flowbird.group Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-21fs: move filp_close() outside of __close_fd_get_file()Jens Axboe1-2/+4
Just one caller of this, and just use filp_close() there manually. This is important to allow async close/removal of the fd. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-14binder: fix incorrect calculation for num_validTodd Kjos1-2/+2
For BINDER_TYPE_PTR and BINDER_TYPE_FDA transactions, the num_valid local was calculated incorrectly causing the range check in binder_validate_ptr() to miss out-of-bounds offsets. Fixes: bde4a19fc04f ("binder: use userspace pointer as base of buffer space") Signed-off-by: Todd Kjos <tkjos@google.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191213202531.55010-1-tkjos@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-02Merge tag 'compat-ioctl-5.5' of ↵Linus Torvalds1-1/+1
git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground Pull removal of most of fs/compat_ioctl.c from Arnd Bergmann: "As part of the cleanup of some remaining y2038 issues, I came to fs/compat_ioctl.c, which still has a couple of commands that need support for time64_t. In completely unrelated work, I spent time on cleaning up parts of this file in the past, moving things out into drivers instead. After Al Viro reviewed an earlier version of this series and did a lot more of that cleanup, I decided to try to completely eliminate the rest of it and move it all into drivers. This series incorporates some of Al's work and many patches of my own, but in the end stops short of actually removing the last part, which is the scsi ioctl handlers. I have patches for those as well, but they need more testing or possibly a rewrite" * tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (42 commits) scsi: sd: enable compat ioctls for sed-opal pktcdvd: add compat_ioctl handler compat_ioctl: move SG_GET_REQUEST_TABLE handling compat_ioctl: ppp: move simple commands into ppp_generic.c compat_ioctl: handle PPPIOCGIDLE for 64-bit time_t compat_ioctl: move PPPIOCSCOMPRESS to ppp_generic compat_ioctl: unify copy-in of ppp filters tty: handle compat PPP ioctls compat_ioctl: move SIOCOUTQ out of compat_ioctl.c compat_ioctl: handle SIOCOUTQNSD af_unix: add compat_ioctl support compat_ioctl: reimplement SG_IO handling compat_ioctl: move WDIOC handling into wdt drivers fs: compat_ioctl: move FITRIM emulation into file systems gfs2: add compat_ioctl support compat_ioctl: remove unused convert_in_user macro compat_ioctl: remove last RAID handling code compat_ioctl: remove /dev/raw ioctl translation compat_ioctl: remove PCI ioctl translation compat_ioctl: remove joystick ioctl translation ...
2019-10-27Merge 5.4-rc5 into char-misc-nextGreg Kroah-Hartman1-7/+0
We want the binder fix in here as well for testing and to work on top of. Also handles a merge issue in binder.c to help linux-next out Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-23compat_ioctl: move more drivers to compat_ptr_ioctlArnd Bergmann1-1/+1
The .ioctl and .compat_ioctl file operations have the same prototype so they can both point to the same function, which works great almost all the time when all the commands are compatible. One exception is the s390 architecture, where a compat pointer is only 31 bit wide, and converting it into a 64-bit pointer requires calling compat_ptr(). Most drivers here will never run in s390, but since we now have a generic helper for it, it's easy enough to use it consistently. I double-checked all these drivers to ensure that all ioctl arguments are used as pointers or are ignored, but are not interpreted as integer values. Acked-by: Jason Gunthorpe <jgg@mellanox.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: David Sterba <dsterba@suse.com> Acked-by: Darren Hart (VMware) <dvhart@infradead.org> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-10-17binder: Use common definition of SZ_1KJann Horn1-5/+1
SZ_1K has been defined in include/linux/sizes.h since v3.6. Get rid of the duplicate definition. Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/20191016150119.154756-2-jannh@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-17binder: Don't modify VMA bounds in ->mmap handlerJann Horn1-7/+0
binder_mmap() tries to prevent the creation of overly big binder mappings by silently truncating the size of the VMA to 4MiB. However, this violates the API contract of mmap(). If userspace attempts to create a large binder VMA, and later attempts to unmap that VMA, it will call munmap() on a range beyond the end of the VMA, which may have been allocated to another VMA in the meantime. This can lead to userspace memory corruption. The following sequence of calls leads to a segfault without this commit: int main(void) { int binder_fd = open("/dev/binder", O_RDWR); if (binder_fd == -1) err(1, "open binder"); void *binder_mapping = mmap(NULL, 0x800000UL, PROT_READ, MAP_SHARED, binder_fd, 0); if (binder_mapping == MAP_FAILED) err(1, "mmap binder"); void *data_mapping = mmap(NULL, 0x400000UL, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); if (data_mapping == MAP_FAILED) err(1, "mmap data"); munmap(binder_mapping, 0x800000UL); *(char*)data_mapping = 1; return 0; } Cc: stable@vger.kernel.org Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Todd Kjos <tkjos@google.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/20191016150119.154756-1-jannh@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-10binder: prevent UAF read in print_binder_transaction_log_entry()Christian Brauner1-1/+3
When a binder transaction is initiated on a binder device coming from a binderfs instance, a pointer to the name of the binder device is stashed in the binder_transaction_log_entry's context_name member. Later on it is used to print the name in print_binder_transaction_log_entry(). By the time print_binder_transaction_log_entry() accesses context_name binderfs_evict_inode() might have already freed the associated memory thereby causing a UAF. Do the simple thing and prevent this by copying the name of the binder device instead of stashing a pointer to it. Reported-by: Jann Horn <jannh@google.com> Fixes: 03e2e07e3814 ("binder: Make transaction_log available in binderfs") Link: https://lore.kernel.org/r/CAG48ez14Q0-F8LqsvcNbyR2o6gPW8SHXsm4u5jmD9MpsteM2Tw@mail.gmail.com Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Acked-by: Todd Kjos <tkjos@google.com> Reviewed-by: Hridya Valsaraju <hridya@google.com> Link: https://lore.kernel.org/r/20191008130159.10161-1-christian.brauner@ubuntu.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04binder: Add binder_proc logging to binderfsHridya Valsaraju1-2/+44
Currently /sys/kernel/debug/binder/proc contains the debug data for every binder_proc instance. This patch makes this information also available in a binderfs instance mounted with a mount option "stats=global" in addition to debugfs. The patch does not affect the presence of the file in debugfs. If a binderfs instance is mounted at path /dev/binderfs, this file would be present at /dev/binderfs/binder_logs/proc. This change provides an alternate way to access this file when debugfs is not mounted. Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Hridya Valsaraju <hridya@google.com> Link: https://lore.kernel.org/r/20190903161655.107408-5-hridya@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04binder: Make transaction_log available in binderfsHridya Valsaraju1-29/+5
Currently, the binder transaction log files 'transaction_log' and 'failed_transaction_log' live in debugfs at the following locations: /sys/kernel/debug/binder/failed_transaction_log /sys/kernel/debug/binder/transaction_log This patch makes these files also available in a binderfs instance mounted with the mount option "stats=global". It does not affect the presence of these files in debugfs. If a binderfs instance is mounted at path /dev/binderfs, the location of these files will be as follows: /dev/binderfs/binder_logs/failed_transaction_log /dev/binderfs/binder_logs/transaction_log This change provides an alternate option to access these files when debugfs is not mounted. Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Hridya Valsaraju <hridya@google.com> Link: https://lore.kernel.org/r/20190903161655.107408-4-hridya@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04binder: Add stats, state and transactions filesHridya Valsaraju1-9/+6
The following binder stat files currently live in debugfs. /sys/kernel/debug/binder/state /sys/kernel/debug/binder/stats /sys/kernel/debug/binder/transactions This patch makes these files available in a binderfs instance mounted with the mount option 'stats=global'. For example, if a binderfs instance is mounted at path /dev/binderfs, the above files will be available at the following locations: /dev/binderfs/binder_logs/state /dev/binderfs/binder_logs/stats /dev/binderfs/binder_logs/transactions This provides a way to access them even when debugfs is not mounted. Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Hridya Valsaraju <hridya@google.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/20190903161655.107408-3-hridya@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04binder: Add default binder devices through binderfs when configuredHridya Valsaraju1-2/+3
Currently, since each binderfs instance needs its own private binder devices, every time a binderfs instance is mounted, all the default binder devices need to be created via the BINDER_CTL_ADD IOCTL. This patch aims to add a solution to automatically create the default binder devices for each binderfs instance that gets mounted. To achieve this goal, when CONFIG_ANDROID_BINDERFS is set, the default binder devices specified by CONFIG_ANDROID_BINDER_DEVICES are created in each binderfs instance instead of global devices being created by the binder driver. Co-developed-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Hridya Valsaraju <hridya@google.com> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Link: https://lore.kernel.org/r/20190808222727.132744-2-hridya@google.com Link: https://lore.kernel.org/r/20190904110704.8606-2-christian.brauner@ubuntu.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-24binder: prevent transactions to context manager from its own process.Hridya Valsaraju1-1/+1
Currently, a transaction to context manager from its own process is prevented by checking if its binder_proc struct is the same as that of the sender. However, this would not catch cases where the process opens the binder device again and uses the new fd to send a transaction to the context manager. Reported-by: syzbot+8b3c354d33c4ac78bfad@syzkaller.appspotmail.com Signed-off-by: Hridya Valsaraju <hridya@google.com> Acked-by: Todd Kjos <tkjos@google.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20190715191804.112933-1-hridya@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-24binder: Set end of SG buffer area properly.Martijn Coenen1-1/+2
In case the target node requests a security context, the extra_buffers_size is increased with the size of the security context. But, that size is not available for use by regular scatter-gather buffers; make sure the ending of that buffer is marked correctly. Acked-by: Todd Kjos <tkjos@google.com> Fixes: ec74136ded79 ("binder: create node flag to request sender's security context") Signed-off-by: Martijn Coenen <maco@android.com> Cc: stable@vger.kernel.org # 5.1+ Link: https://lore.kernel.org/r/20190709110923.220736-1-maco@android.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-01binder: return errors from buffer copy functionsTodd Kjos1-61/+92
The buffer copy functions assumed the caller would ensure correct alignment and that the memory to be copied was completely within the binder buffer. There have been a few cases discovered by syzkallar where a malformed transaction created by a user could violated the assumptions and resulted in a BUG_ON. The fix is to remove the BUG_ON and always return the error to be handled appropriately by the caller. Acked-by: Martijn Coenen <maco@android.com> Reported-by: syzbot+3ae18325f96190606754@syzkaller.appspotmail.com Fixes: bde4a19fc04f ("binder: use userspace pointer as base of buffer space") Suggested-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Todd Kjos <tkjos@google.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-23Merge 5.2-rc6 into char-misc-nextGreg Kroah-Hartman1-2/+14
We need the char-misc fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-22binder: fix memory leak in error pathTodd Kjos1-2/+2
syzkallar found a 32-byte memory leak in a rarely executed error case. The transaction complete work item was not freed if put_user() failed when writing the BR_TRANSACTION_COMPLETE to the user command buffer. Fixed by freeing it before put_user() is called. Reported-by: syzbot+182ce46596c3f2e1eb24@syzkaller.appspotmail.com Signed-off-by: Todd Kjos <tkjos@google.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-13binder: fix possible UAF when freeing bufferTodd Kjos1-2/+14
There is a race between the binder driver cleaning up a completed transaction via binder_free_transaction() and a user calling binder_ioctl(BC_FREE_BUFFER) to release a buffer. It doesn't matter which is first but they need to be protected against running concurrently which can result in a UAF. Signed-off-by: Todd Kjos <tkjos@google.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282Thomas Gleixner1-10/+1
Based on 1 normalized pattern(s): this software is licensed under the terms of the gnu general public license version 2 as published by the free software foundation and may be copied distributed and modified under those terms this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 285 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25binder: check for overflow when alloc for security contextTodd Kjos1-1/+11
When allocating space in the target buffer for the security context, make sure the extra_buffers_size doesn't overflow. This can only happen if the given size is invalid, but an overflow can turn it into a valid size. Fail the transaction if an overflow is detected. Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-21binder: fix BUG_ON found by selinux-testsuiteTodd Kjos1-1/+2
The selinux-testsuite found an issue resulting in a BUG_ON() where a conditional relied on a size_t going negative when checking the validity of a buffer offset. Fixes: 7a67a39320df ("binder: add function to copy binder object from buffer") Reported-by: Paul Moore <paul@paul-moore.com> Tested-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-15binder: fix handling of misaligned binder objectTodd Kjos1-1/+1
Fixes crash found by syzbot: kernel BUG at drivers/android/binder_alloc.c:LINE! (2) Reported-and-tested-by: syzbot+55de1eb4975dec156d8f@syzkaller.appspotmail.com Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12binder: use userspace pointer as base of buffer spaceTodd Kjos1-51/+67
Now that alloc->buffer points to the userspace vm_area rename buffer->data to buffer->user_data and rename local pointers that hold user addresses. Also use the "__user" tag to annotate all user pointers so sparse can flag cases where user pointer vaues are copied to kernel pointers. Refactor code to use offsets instead of user pointers. Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12binder: remove user_buffer_offsetTodd Kjos1-32/+7
Remove user_buffer_offset since there is no kernel buffer pointer anymore. Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12binder: avoid kernel vm_area for buffer fixupsTodd Kjos1-49/+97
Refactor the functions to validate and fixup struct binder_buffer pointer objects to avoid using vm_area pointers. Instead copy to/from kernel space using binder_alloc_copy_to_buffer() and binder_alloc_copy_from_buffer(). The following functions were refactored: refactor binder_validate_ptr() binder_validate_fixup() binder_fixup_parent() Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12binder: add function to copy binder object from bufferTodd Kjos1-17/+58
When creating or tearing down a transaction, the binder driver examines objects in the buffer and takes appropriate action. To do this without needing to dereference pointers into the buffer, the local copies of the objects are needed. This patch introduces a function to validate and copy binder objects from the buffer to a local structure. Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12binder: add functions to copy to/from binder buffersTodd Kjos1-44/+75
Avoid vm_area when copying to or from binder buffers. Instead, new copy functions are added that copy from kernel space to binder buffer space. These use kmap_atomic() and kunmap_atomic() to create temporary mappings and then memcpy() is used to copy within that page. Also, kmap_atomic() / kunmap_atomic() use the appropriate cache flushing to support VIVT cache architectures. Allow binder to build if CPU_CACHE_VIVT is defined. Several uses of the new functions are added here. More to follow in subsequent patches. Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12binder: create userspace-to-binder-buffer copy functionTodd Kjos1-7/+22
The binder driver uses a vm_area to map the per-process binder buffer space. For 32-bit android devices, this is now taking too much vmalloc space. This patch removes the use of vm_area when copying the transaction data from the sender to the buffer space. Instead of using copy_from_user() for multi-page copies, it now uses binder_alloc_copy_user_to_buffer() which uses kmap() and kunmap() to map each page, and uses copy_from_user() for copying to that page. Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-11Merge 5.0-rc6 into char-misc-nextGreg Kroah-Hartman1-15/+22
We need the char-misc fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-01binderfs: remove separate device_initcall()Christian Brauner1-1/+6
binderfs should not have a separate device_initcall(). When a kernel is compiled with CONFIG_ANDROID_BINDERFS register the filesystem alongside CONFIG_ANDROID_IPC. This use-case is especially sensible when users specify CONFIG_ANDROID_IPC=y, CONFIG_ANDROID_BINDERFS=y and ANDROID_BINDER_DEVICES="". When CONFIG_ANDROID_BINDERFS=n then this always succeeds so there's no regression potential for legacy workloads. Signed-off-by: Christian Brauner <christian@brauner.io> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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