kernel.git/drivers/ptp/ptp_clock.c, branch linux-4.4.y

ptp: free ptp device pin descriptors properly

2020-05-20T06:11:41Z

commit 75718584cb3c64e6269109d4d54f888ac5a5fd15 upstream. There is a bug in ptp_clock_unregister(), where ptp_cleanup_pin_groups() first frees ptp->pin_{,dev_}attr, but then posix_clock_unregister() needs them to destroy a related sysfs device. These functions can not be just swapped, as posix_clock_unregister() frees ptp which is needed in the ptp_cleanup_pin_groups(). Fix this by calling ptp_cleanup_pin_groups() in ptp_clock_release(), right before ptp is freed. This makes this patch fix an UAF bug in a patch which fixes an UAF bug. Reported-by: Antti Laakso Fixes: a33121e5487b ("ptp: fix the race between the release of ptp_clock and cdev") Link: https://lore.kernel.org/netdev/3d2bd09735dbdaf003585ca376b7c1e5b69a19bd.camel@intel.com/ Signed-off-by: Vladis Dronov Acked-by: Richard Cochran Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

ptp: fix the race between the release of ptp_clock and cdev

2020-05-20T06:11:41Z

commit a33121e5487b424339636b25c35d3a180eaa5f5e upstream. In a case when a ptp chardev (like /dev/ptp0) is open but an underlying device is removed, closing this file leads to a race. This reproduces easily in a kvm virtual machine: ts# cat openptp0.c int main() { ... fp = fopen("/dev/ptp0", "r"); ... sleep(10); } ts# uname -r 5.5.0-rc3-46cf053e ts# cat /proc/cmdline ... slub_debug=FZP ts# modprobe ptp_kvm ts# ./openptp0 & [1] 670 opened /dev/ptp0, sleeping 10s... ts# rmmod ptp_kvm ts# ls /dev/ptp* ls: cannot access '/dev/ptp*': No such file or directory ts# ...woken up [ 48.010809] general protection fault: 0000 [#1] SMP [ 48.012502] CPU: 6 PID: 658 Comm: openptp0 Not tainted 5.5.0-rc3-46cf053e #25 [ 48.014624] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ... [ 48.016270] RIP: 0010:module_put.part.0+0x7/0x80 [ 48.017939] RSP: 0018:ffffb3850073be00 EFLAGS: 00010202 [ 48.018339] RAX: 000000006b6b6b6b RBX: 6b6b6b6b6b6b6b6b RCX: ffff89a476c00ad0 [ 48.018936] RDX: fffff65a08d3ea08 RSI: 0000000000000247 RDI: 6b6b6b6b6b6b6b6b [ 48.019470] ... ^^^ a slub poison [ 48.023854] Call Trace: [ 48.024050] __fput+0x21f/0x240 [ 48.024288] task_work_run+0x79/0x90 [ 48.024555] do_exit+0x2af/0xab0 [ 48.024799] ? vfs_write+0x16a/0x190 [ 48.025082] do_group_exit+0x35/0x90 [ 48.025387] __x64_sys_exit_group+0xf/0x10 [ 48.025737] do_syscall_64+0x3d/0x130 [ 48.026056] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.026479] RIP: 0033:0x7f53b12082f6 [ 48.026792] ... [ 48.030945] Modules linked in: ptp i6300esb watchdog [last unloaded: ptp_kvm] [ 48.045001] Fixing recursive fault but reboot is needed! This happens in: static void __fput(struct file *file) { ... if (file->f_op->release) file->f_op->release(inode, file); <<< cdev is kfree'd here if (unlikely(S_ISCHR(inode->i_mode) && inode->i_cdev != NULL && !(mode & FMODE_PATH))) { cdev_put(inode->i_cdev); <<< cdev fields are accessed here Namely: __fput() posix_clock_release() kref_put(&clk->kref, delete_clock) <<< the last reference delete_clock() delete_ptp_clock() kfree(ptp) <<< cdev is embedded in ptp cdev_put module_put(p->owner) <<< *p is kfree'd, bang! Here cdev is embedded in posix_clock which is embedded in ptp_clock. The race happens because ptp_clock's lifetime is controlled by two refcounts: kref and cdev.kobj in posix_clock. This is wrong. Make ptp_clock's sysfs device a parent of cdev with cdev_device_add() created especially for such cases. This way the parent device with its ptp_clock is not released until all references to the cdev are released. This adds a requirement that an initialized but not exposed struct device should be provided to posix_clock_register() by a caller instead of a simple dev_t. This approach was adopted from the commit 72139dfa2464 ("watchdog: Fix the race between the release of watchdog_core_data and cdev"). See details of the implementation in the commit 233ed09d7fda ("chardev: add helper function to register char devs with a struct device"). Link: https://lore.kernel.org/linux-fsdevel/20191125125342.6189-1-vdronov@redhat.com/T/#u Analyzed-by: Stephen Johnston Analyzed-by: Vern Lovejoy Signed-off-by: Vladis Dronov Acked-by: Richard Cochran Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

ptp: Fix pass zero to ERR_PTR() in ptp_clock_register

2020-05-20T06:11:40Z

commit aea0a897af9e44c258e8ab9296fad417f1bc063a upstream. Fix smatch warning: drivers/ptp/ptp_clock.c:298 ptp_clock_register() warn: passing zero to 'ERR_PTR' 'err' should be set while device_create_with_groups and pps_register_source fails Fixes: 85a66e550195 ("ptp: create "pins" together with the rest of attributes") Signed-off-by: YueHaibing Acked-by: Richard Cochran Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

ptp: create "pins" together with the rest of attributes

2020-05-20T06:11:40Z

commit 85a66e55019583da1e0f18706b7a8281c9f6de5b upstream. Let's switch to using device_create_with_groups(), which will allow us to create "pins" attribute group together with the rest of ptp device attributes, and before userspace gets notified about ptp device creation. Signed-off-by: Dmitry Torokhov Signed-off-by: David S. Miller [bwh: Backported to 4.9: adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

ptp: do not explicitly set drvdata in ptp_clock_register()

2020-05-20T06:11:39Z

commit 882f312dc0751c973db26478f07f082c584d16aa upstream. We do not need explicitly call dev_set_drvdata(), as it is done for us by device_create(). Acked-by: Richard Cochran Signed-off-by: Dmitry Torokhov Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

time: Change posix clocks ops interfaces to use timespec64

2018-03-24T09:58:40Z

[ Upstream commit d340266e19ddb70dbd608f9deedcfb35fdb9d419 ] struct timespec is not y2038 safe on 32 bit machines. The posix clocks apis use struct timespec directly and through struct itimerspec. Replace the posix clock interfaces to use struct timespec64 and struct itimerspec64 instead. Also fix up their implementations accordingly. Note that the clock_getres() interface has also been changed to use timespec64 even though this particular interface is not affected by the y2038 problem. This helps verification for internal kernel code for y2038 readiness by getting rid of time_t/ timeval/ timespec. Signed-off-by: Deepa Dinamani Cc: arnd@arndb.de Cc: y2038@lists.linaro.org Cc: netdev@vger.kernel.org Cc: Richard Cochran Cc: john.stultz@linaro.org Link: http://lkml.kernel.org/r/1490555058-4603-3-git-send-email-deepa.kernel@gmail.com Signed-off-by: Thomas Gleixner Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ptp: remove 32 bit get/set methods.

2015-03-31T16:01:19Z

All of the PHC drivers have been converted to the new methods. This patch converts the three remaining callers within the core code and removes the older methods for good. As a result, the core PHC code is ready for the year 2038. However, some of the PHC drivers are not quite ready yet. Signed-off-by: Richard Cochran Signed-off-by: David S. Miller

ptp: use the 64 bit get/set time methods for the posix clock.

2015-03-31T16:01:16Z

This patch changes the posix clock code to prefer the new methods whenever they are implemented by the PHC drivers. Signed-off-by: Richard Cochran Signed-off-by: David S. Miller

ptp: validate the requested frequency adjustment.

2014-04-28T17:28:43Z

PTP Hardware Clock drivers specify a maximum frequency adjustment that their clocks can accommodate. Normally, user space programs will want to respect the advertised limits. However, no kernel or driver code checks that the dialed frequency offset is within the bounds, and out of range values can lead to surprising results. This patch fixes the issue by rejecting bad values. Signed-off-by: Richard Cochran Signed-off-by: David S. Miller

ptp: introduce programmable pins.

2014-03-21T18:21:13Z

This patch adds a pair of new ioctls to the PTP Hardware Clock device interface. Using the ioctls, user space programs can query each pin to find out its current function and also reprogram a different function if desired. Signed-off-by: Richard Cochran Signed-off-by: David S. Miller