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2016-03-09modules: fix longstanding /proc/kallsyms vs module insertion race.Rusty Russell
commit 8244062ef1e54502ef55f54cced659913f244c3e upstream. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). [ Rebased for 4.4-stable and older, because the following changes aren't in the older trees: - e0224418516b4d8a6c2160574bac18447c354ef0: adds arg to is_core_symbol - 7523e4dc5057e157212b4741abd6256e03404cf1: module_init/module_core/init_size/core_size become init_layout.base/core_layout.base/init_layout.size/core_layout.size. ] Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-09block: get the 1st and last bvec via helpersMing Lei
commit 25e71a99f10e444cd00bb2ebccb11e1c9fb672b1 upstream. This patch applies the two introduced helpers to figure out the 1st and last bvec, and fixes the original way after bio splitting. Reported-by: Sagi Grimberg <sagig@dev.mellanox.co.il> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-09block: check virt boundary in bio_will_gap()Ming Lei
commit e0af29171aa8912e1ca95023b75ef336cd70d661 upstream. In the following patch, the way for figuring out the last bvec will be changed with a bit cost introduced, so return immediately if the queue doesn't have virt boundary limit. Actually most of devices have not this limit. Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-09tracing: Do not have 'comm' filter override event 'comm' fieldSteven Rostedt (Red Hat)
commit e57cbaf0eb006eaa207395f3bfd7ce52c1b5539c upstream. Commit 9f61668073a8d "tracing: Allow triggers to filter for CPU ids and process names" added a 'comm' filter that will filter events based on the current tasks struct 'comm'. But this now hides the ability to filter events that have a 'comm' field too. For example, sched_migrate_task trace event. That has a 'comm' field of the task to be migrated. echo 'comm == "bash"' > events/sched_migrate_task/filter will now filter all sched_migrate_task events for tasks named "bash" that migrates other tasks (in interrupt context), instead of seeing when "bash" itself gets migrated. This fix requires a couple of changes. 1) Change the look up order for filter predicates to look at the events fields before looking at the generic filters. 2) Instead of basing the filter function off of the "comm" name, have the generic "comm" filter have its own filter_type (FILTER_COMM). Test against the type instead of the name to assign the filter function. 3) Add a new "COMM" filter that works just like "comm" but will filter based on the current task, even if the trace event contains a "comm" field. Do the same for "cpu" field, adding a FILTER_CPU and a filter "CPU". Fixes: 9f61668073a8d "tracing: Allow triggers to filter for CPU ids and process names" Reported-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-09writeback: flush inode cgroup wb switches instead of pinning super_blockTejun Heo
commit a1a0e23e49037c23ea84bc8cc146a03584d13577 upstream. If cgroup writeback is in use, inodes can be scheduled for asynchronous wb switching. Before 5ff8eaac1636 ("writeback: keep superblock pinned during cgroup writeback association switches"), this could race with umount leading to super_block being destroyed while inodes are pinned for wb switching. 5ff8eaac1636 fixed it by bumping s_active while wb switches are in flight; however, this allowed in-flight wb switches to make umounts asynchronous when the userland expected synchronosity - e.g. fsck immediately following umount may fail because the device is still busy. This patch removes the problematic super_block pinning and instead makes generic_shutdown_super() flush in-flight wb switches. wb switches are now executed on a dedicated isw_wq so that they can be flushed and isw_nr_in_flight keeps track of the number of in-flight wb switches so that flushing can be avoided in most cases. v2: Move cgroup_writeback_umount() further below and add MS_ACTIVE check in inode_switch_wbs() as Jan an Al suggested. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Tahsin Erdogan <tahsin@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@ZenIV.linux.org.uk> Link: http://lkml.kernel.org/g/CAAeU0aNCq7LGODvVGRU-oU_o-6enii5ey0p1c26D1ZzYwkDc5A@mail.gmail.com Fixes: 5ff8eaac1636 ("writeback: keep superblock pinned during cgroup writeback association switches") Reviewed-by: Jan Kara <jack@suse.cz> Tested-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-09block: bio: introduce helpers to get the 1st and last bvecMing Lei
commit 7bcd79ac50d9d83350a835bdb91c04ac9e098412 upstream. The bio passed to bio_will_gap() may be fast cloned from upper layer(dm, md, bcache, fs, ...), or from bio splitting in block core. Unfortunately bio_will_gap() just figures out the last bvec via 'bi_io_vec[prev->bi_vcnt - 1]' directly, and this way is obviously wrong. This patch introduces two helpers for getting the first and last bvec of one bio for fixing the issue. Reported-by: Sagi Grimberg <sagig@dev.mellanox.co.il> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-09libata: Align ata_device's id on a cachelineHarvey Hunt
commit 4ee34ea3a12396f35b26d90a094c75db95080baa upstream. The id buffer in ata_device is a DMA target, but it isn't explicitly cacheline aligned. Due to this, adjacent fields can be overwritten with stale data from memory on non coherent architectures. As a result, the kernel is sometimes unable to communicate with an ATA device. Fix this by ensuring that the id buffer is cacheline aligned. This issue is similar to that fixed by Commit 84bda12af31f ("libata: align ap->sector_buf"). Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-09libata: fix HDIO_GET_32BIT ioctlArnd Bergmann
commit 287e6611ab1eac76c2c5ebf6e345e04c80ca9c61 upstream. As reported by Soohoon Lee, the HDIO_GET_32BIT ioctl does not work correctly in compat mode with libata. I have investigated the issue further and found multiple problems that all appeared with the same commit that originally introduced HDIO_GET_32BIT handling in libata back in linux-2.6.8 and presumably also linux-2.4, as the code uses "copy_to_user(arg, &val, 1)" to copy a 'long' variable containing either 0 or 1 to user space. The problems with this are: * On big-endian machines, this will always write a zero because it stores the wrong byte into user space. * In compat mode, the upper three bytes of the variable are updated by the compat_hdio_ioctl() function, but they now contain uninitialized stack data. * The hdparm tool calling this ioctl uses a 'static long' variable to store the result. This means at least the upper bytes are initialized to zero, but calling another ioctl like HDIO_GET_MULTCOUNT would fill them with data that remains stale when the low byte is overwritten. Fortunately libata doesn't implement any of the affected ioctl commands, so this would only happen when we query both an IDE and an ATA device in the same command such as "hdparm -N -c /dev/hda /dev/sda" * The libata code for unknown reasons started using ATA_IOC_GET_IO32 and ATA_IOC_SET_IO32 as aliases for HDIO_GET_32BIT and HDIO_SET_32BIT, while the ioctl commands that were added later use the normal HDIO_* names. This is harmless but rather confusing. This addresses all four issues by changing the code to use put_user() on an 'unsigned long' variable in HDIO_GET_32BIT, like the IDE subsystem does, and by clarifying the names of the ioctl commands. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reported-by: Soohoon Lee <Soohoon.Lee@f5.com> Tested-by: Soohoon Lee <Soohoon.Lee@f5.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-09target: Fix WRITE_SAME/DISCARD conversion to linux 512b sectorsMike Christie
commit 8a9ebe717a133ba7bc90b06047f43cc6b8bcb8b3 upstream. In a couple places we are not converting to/from the Linux block layer 512 bytes sectors. 1. The request queue values and what we do are a mismatch of things: max_discard_sectors - This is in linux block layer 512 byte sectors. We are just copying this to max_unmap_lba_count. discard_granularity - This is in bytes. We are converting it to Linux block layer 512 byte sectors. discard_alignment - This is in bytes. We are just copying this over. The problem is that the core LIO code exports these values in spc_emulate_evpd_b0 and we use them to test request arguments in sbc_execute_unmap, but we never convert to the block size we export to the initiator. If we are not using 512 byte sectors then we are exporting the wrong values or are checks are off. And, for the discard_alignment/bytes case we are just plain messed up. 2. blkdev_issue_discard's start and number of sector arguments are supposed to be in linux block layer 512 byte sectors. We are currently passing in the values we get from the initiator which might be based on some other sector size. There is a similar problem in iblock_execute_write_same where the bio functions want values in 512 byte sectors but we are passing in what we got from the initiator. Signed-off-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> [ kamal: backport to 4.4-stable: no unmap_zeroes_data ] Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-09use ->d_seq to get coherency between ->d_inode and ->d_flagsAl Viro
commit a528aca7f359f4b0b1d72ae406097e491a5ba9ea upstream. Games with ordering and barriers are way too brittle. Just bump ->d_seq before and after updating ->d_inode and ->d_flags type bits, so that verifying ->d_seq would guarantee they are coherent. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03nfs: fix nfs_size_to_loff_tChristoph Hellwig
commit 50ab8ec74a153eb30db26529088bc57dd700b24c upstream. See http: //www.infradead.org/rpr.html X-Evolution-Source: 1451162204.2173.11@leira.trondhjem.org Content-Transfer-Encoding: 8bit Mime-Version: 1.0 We support OFFSET_MAX just fine, so don't round down below it. Also switch to using min_t to make the helper more readable. Signed-off-by: Christoph Hellwig <hch@lst.de> Fixes: 433c92379d9c ("NFS: Clean up nfs_size_to_loff_t()") Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03cgroup: make sure a parent css isn't offlined before its childrenTejun Heo
commit aa226ff4a1ce79f229c6b7a4c0a14e17fececd01 upstream. There are three subsystem callbacks in css shutdown path - css_offline(), css_released() and css_free(). Except for css_released(), cgroup core didn't guarantee the order of invocation. css_offline() or css_free() could be called on a parent css before its children. This behavior is unexpected and led to bugs in cpu and memory controller. This patch updates offline path so that a parent css is never offlined before its children. Each css keeps online_cnt which reaches zero iff itself and all its children are offline and offline_css() is invoked only after online_cnt reaches zero. This fixes the memory controller bug and allows the fix for cpu controller. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-and-tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Reported-by: Brian Christiansen <brian.o.christiansen@gmail.com> Link: http://lkml.kernel.org/g/5698A023.9070703@de.ibm.com Link: http://lkml.kernel.org/g/CAKB58ikDkzc8REt31WBkD99+hxNzjK4+FBmhkgS+NVrC9vjMSg@mail.gmail.com Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03cpuset: make mm migration asynchronousTejun Heo
commit e93ad19d05648397ef3bcb838d26aec06c245dc0 upstream. If "cpuset.memory_migrate" is set, when a process is moved from one cpuset to another with a different memory node mask, pages in used by the process are migrated to the new set of nodes. This was performed synchronously in the ->attach() callback, which is synchronized against process management. Recently, the synchronization was changed from per-process rwsem to global percpu rwsem for simplicity and optimization. Combined with the synchronous mm migration, this led to deadlocks because mm migration could schedule a work item which may in turn try to create a new worker blocking on the process management lock held from cgroup process migration path. This heavy an operation shouldn't be performed synchronously from that deep inside cgroup migration in the first place. This patch punts the actual migration to an ordered workqueue and updates cgroup process migration and cpuset config update paths to flush the workqueue after all locks are released. This way, the operations still seem synchronous to userland without entangling mm migration with process management synchronization. CPU hotplug can also invoke mm migration but there's no reason for it to wait for mm migrations and thus doesn't synchronize against their completions. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-and-tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03target: Fix remote-port TMR ABORT + se_cmd fabric stopNicholas Bellinger
commit 0f4a943168f31d29a1701908931acaba518b131a upstream. To address the bug where fabric driver level shutdown of se_cmd occurs at the same time when TMR CMD_T_ABORTED is happening resulting in a -1 ->cmd_kref, this patch adds a CMD_T_FABRIC_STOP bit that is used to determine when TMR + driver I_T nexus shutdown is happening concurrently. It changes target_sess_cmd_list_set_waiting() to obtain se_cmd->cmd_kref + set CMD_T_FABRIC_STOP, and drop local reference in target_wait_for_sess_cmds() and invoke extra target_put_sess_cmd() during Task Aborted Status (TAS) when necessary. Also, it adds a new target_wait_free_cmd() wrapper around transport_wait_for_tasks() for the special case within transport_generic_free_cmd() to set CMD_T_FABRIC_STOP, and is now aware of CMD_T_ABORTED + CMD_T_TAS status bits to know when an extra transport_put_cmd() during TAS is required. Note transport_generic_free_cmd() is expected to block on cmd->cmd_wait_comp in order to follow what iscsi-target expects during iscsi_conn context se_cmd shutdown. Cc: Quinn Tran <quinn.tran@qlogic.com> Cc: Himanshu Madhani <himanshu.madhani@qlogic.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Andy Grover <agrover@redhat.com> Cc: Mike Christie <mchristi@redhat.com> Signed-off-by: Nicholas Bellinger <nab@daterainc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03target: Fix LUN_RESET active I/O handling for ACK_KREFNicholas Bellinger
commit febe562c20dfa8f33bee7d419c6b517986a5aa33 upstream. This patch fixes a NULL pointer se_cmd->cmd_kref < 0 refcount bug during TMR LUN_RESET with active se_cmd I/O, that can be triggered during se_cmd descriptor shutdown + release via core_tmr_drain_state_list() code. To address this bug, add common __target_check_io_state() helper for ABORT_TASK + LUN_RESET w/ CMD_T_COMPLETE checking, and set CMD_T_ABORTED + obtain ->cmd_kref for both cases ahead of last target_put_sess_cmd() after TFO->aborted_task() -> transport_cmd_finish_abort() callback has completed. It also introduces SCF_ACK_KREF to determine when transport_cmd_finish_abort() needs to drop the second extra reference, ahead of calling target_put_sess_cmd() for the final kref_put(&se_cmd->cmd_kref). It also updates transport_cmd_check_stop() to avoid holding se_cmd->t_state_lock while dropping se_cmd device state via target_remove_from_state_list(), now that core_tmr_drain_state_list() is holding the se_device lock while checking se_cmd state from within TMR logic. Finally, move transport_put_cmd() release of SGL + TMR + extended CDB memory into target_free_cmd_mem() in order to avoid potential resource leaks in TMR ABORT_TASK + LUN_RESET code-paths. Also update target_release_cmd_kref() accordingly. Reviewed-by: Quinn Tran <quinn.tran@qlogic.com> Cc: Himanshu Madhani <himanshu.madhani@qlogic.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Andy Grover <agrover@redhat.com> Cc: Mike Christie <mchristi@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03libceph: fix ceph_msg_revoke()Ilya Dryomov
commit 67645d7619738e51c668ca69f097cb90b5470422 upstream. There are a number of problems with revoking a "was sending" message: (1) We never make any attempt to revoke data - only kvecs contibute to con->out_skip. However, once the header (envelope) is written to the socket, our peer learns data_len and sets itself to expect at least data_len bytes to follow front or front+middle. If ceph_msg_revoke() is called while the messenger is sending message's data portion, anything we send after that call is counted by the OSD towards the now revoked message's data portion. The effects vary, the most common one is the eventual hang - higher layers get stuck waiting for the reply to the message that was sent out after ceph_msg_revoke() returned and treated by the OSD as a bunch of data bytes. This is what Matt ran into. (2) Flat out zeroing con->out_kvec_bytes worth of bytes to handle kvecs is wrong. If ceph_msg_revoke() is called before the tag is sent out or while the messenger is sending the header, we will get a connection reset, either due to a bad tag (0 is not a valid tag) or a bad header CRC, which kind of defeats the purpose of revoke. Currently the kernel client refuses to work with header CRCs disabled, but that will likely change in the future, making this even worse. (3) con->out_skip is not reset on connection reset, leading to one or more spurious connection resets if we happen to get a real one between con->out_skip is set in ceph_msg_revoke() and before it's cleared in write_partial_skip(). Fixing (1) and (3) is trivial. The idea behind fixing (2) is to never zero the tag or the header, i.e. send out tag+header regardless of when ceph_msg_revoke() is called. That way the header is always correct, no unnecessary resets are induced and revoke stands ready for disabled CRCs. Since ceph_msg_revoke() rips out con->out_msg, introduce a new "message out temp" and copy the header into it before sending. Reported-by: Matt Conner <matt.conner@keepertech.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Tested-by: Matt Conner <matt.conner@keepertech.com> Reviewed-by: Sage Weil <sage@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03Thermal: do thermal zone update after a cooling device registeredChen Yu
commit 4511f7166a2deb5f7a578cf87fd2fe1ae83527e3 upstream. When a new cooling device is registered, we need to update the thermal zone to set the new registered cooling device to a proper state. This fixes a problem that the system is cool, while the fan devices are left running on full speed after boot, if fan device is registered after thermal zone device. Here is the history of why current patch looks like this: https://patchwork.kernel.org/patch/7273041/ Reference:https://bugzilla.kernel.org/show_bug.cgi?id=92431 Tested-by: Manuel Krause <manuelkrause@netscape.net> Tested-by: szegad <szegadlo@poczta.onet.pl> Tested-by: prash <prash.n.rao@gmail.com> Tested-by: amish <ammdispose-arch@yahoo.com> Reviewed-by: Javi Merino <javi.merino@arm.com> Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03Thermal: initialize thermal zone device correctlyZhang Rui
commit bb431ba26c5cd0a17c941ca6c3a195a3a6d5d461 upstream. After thermal zone device registered, as we have not read any temperature before, thus tz->temperature should not be 0, which actually means 0C, and thermal trend is not available. In this case, we need specially handling for the first thermal_zone_device_update(). Both thermal core framework and step_wise governor is enhanced to handle this. And since the step_wise governor is the only one that uses trends, so it's the only thermal governor that needs to be updated. Tested-by: Manuel Krause <manuelkrause@netscape.net> Tested-by: szegad <szegadlo@poczta.onet.pl> Tested-by: prash <prash.n.rao@gmail.com> Tested-by: amish <ammdispose-arch@yahoo.com> Tested-by: Matthias <morpheusxyz123@yahoo.de> Reviewed-by: Javi Merino <javi.merino@arm.com> Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03uapi: update install list after nvme.h renameMike Frysinger
commit a9cf8284b45110a4d98aea180a89c857e53bf850 upstream. Commit 9d99a8dda154 ("nvme: move hardware structures out of the uapi version of nvme.h") renamed nvme.h to nvme_ioctl.h, but the uapi list still refers to nvme.h. People trying to install the headers hit a failure as the header no longer exists. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03make sure that freeing shmem fast symlinks is RCU-delayedAl Viro
commit 3ed47db34f480df7caf44436e3e63e555351ae9a upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03drm: add helper to check for wc memory supportDave Airlie
commit 4b0e4e4af6c6dc8354dcb72182d52c1bc55f12fc upstream. Reviewed-by: Christian König <christian.koenig@amd.com> Reviewed-by: Michel Dänzer <michel.daenzer@amd.com> Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03drm/dp/mst: move GUID storage from mgr, port to only mst branchHersen Wu
commit 5e93b8208d3c419b515fb75e2601931c027e12ab upstream. Previous implementation does not handle case below: boot up one MST branch to DP connector of ASIC. After boot up, hot plug 2nd MST branch to DP output of 1st MST, GUID is not created for 2nd MST branch. When downstream port of 2nd MST branch send upstream request, it fails because 2nd MST branch GUID is not available. New Implementation: only create GUID for MST branch and save it within Branch. Signed-off-by: Hersen Wu <hersenxs.wu@amd.com> Reviewed-by: Harry Wentland <harry.wentland@amd.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03drm: Add drm_fixp_from_fraction and drm_fixp2int_ceilHarry Wentland
commit 64566b5e767f9bc3161055ca1b443a51afb52aad upstream. drm_fixp_from_fraction allows us to create a fixed point directly from a fraction, rather than creating fixed point values and dividing later. This avoids overflow of our 64 bit value for large numbers. drm_fixp2int_ceil allows us to return the ceiling of our fixed point value. [airlied: squash Jordan's fix] 32-bit-build-fix: Jordan Lazare <Jordan.Lazare@amd.com> Signed-off-by: Harry Wentland <harry.wentland@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03drm/dp/mst: always send reply for UP requestMykola Lysenko
commit 1f16ee7fa13649f4e55aa48ad31c3eb0722a62d3 upstream. We should always send reply for UP request in order to make downstream device clean-up resources appropriately. Issue was that reply for UP request was sent only once. Acked-by: Dave Airlie <airlied@gmail.com> Signed-off-by: Mykola Lysenko <Mykola.Lysenko@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03cputime: Prevent 32bit overflow in time[val|spec]_to_cputime()zengtao
commit 0f26922fe5dc5724b1adbbd54b21bad03590b4f3 upstream. The datatype __kernel_time_t is u32 on 32bit platform, so its subject to overflows in the timeval/timespec to cputime conversion. Currently the following functions are affected: 1. setitimer() 2. timer_create/timer_settime() 3. sys_clock_nanosleep This can happen on MIPS32 and ARM32 with "Full dynticks CPU time accounting" enabled, which is required for CONFIG_NO_HZ_FULL. Enforce u64 conversion to prevent the overflow. Fixes: 31c1fc818715 ("ARM: Kconfig: allow full nohz CPU accounting") Signed-off-by: zengtao <prime.zeng@huawei.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/1454384314-154784-1-git-send-email-prime.zeng@huawei.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03Drivers: hv: vmbus: Fix a Host signaling bugK. Y. Srinivasan
commit 8599846d73997cdbccf63f23394d871cfad1e5e6 upstream. Currently we have two policies for deciding when to signal the host: One based on the ring buffer state and the other based on what the VMBUS client driver wants to do. Consider the case when the client wants to explicitly control when to signal the host. In this case, if the client were to defer signaling, we will not be able to signal the host subsequently when the client does want to signal since the ring buffer state will prevent the signaling. Implement logic to have only one signaling policy in force for a given channel. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Tested-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03efi: Make efivarfs entries immutable by defaultPeter Jones
commit ed8b0de5a33d2a2557dce7f9429dca8cb5bc5879 upstream. "rm -rf" is bricking some peoples' laptops because of variables being used to store non-reinitializable firmware driver data that's required to POST the hardware. These are 100% bugs, and they need to be fixed, but in the mean time it shouldn't be easy to *accidentally* brick machines. We have to have delete working, and picking which variables do and don't work for deletion is quite intractable, so instead make everything immutable by default (except for a whitelist), and make tools that aren't quite so broad-spectrum unset the immutable flag. Signed-off-by: Peter Jones <pjones@redhat.com> Tested-by: Lee, Chun-Yi <jlee@suse.com> Acked-by: Matthew Garrett <mjg59@coreos.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03efi: Make our variable validation list include the guidPeter Jones
commit 8282f5d9c17fe15a9e658c06e3f343efae1a2a2f upstream. All the variables in this list so far are defined to be in the global namespace in the UEFI spec, so this just further ensures we're validating the variables we think we are. Including the guid for entries will become more important in future patches when we decide whether or not to allow deletion of variables based on presence in this list. Signed-off-by: Peter Jones <pjones@redhat.com> Tested-by: Lee, Chun-Yi <jlee@suse.com> Acked-by: Matthew Garrett <mjg59@coreos.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03lib/ucs2_string: Add ucs2 -> utf8 helper functionsPeter Jones
commit 73500267c930baadadb0d02284909731baf151f7 upstream. This adds ucs2_utf8size(), which tells us how big our ucs2 string is in bytes, and ucs2_as_utf8, which translates from ucs2 to utf8.. Signed-off-by: Peter Jones <pjones@redhat.com> Tested-by: Lee, Chun-Yi <jlee@suse.com> Acked-by: Matthew Garrett <mjg59@coreos.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03tcp/dccp: fix another race at listener dismantleEric Dumazet
[ Upstream commit 7716682cc58e305e22207d5bb315f26af6b1e243 ] Ilya reported following lockdep splat: kernel: ========================= kernel: [ BUG: held lock freed! ] kernel: 4.5.0-rc1-ceph-00026-g5e0a311 #1 Not tainted kernel: ------------------------- kernel: swapper/5/0 is freeing memory ffff880035c9d200-ffff880035c9dbff, with a lock still held there! kernel: (&(&queue->rskq_lock)->rlock){+.-...}, at: [<ffffffff816f6a88>] inet_csk_reqsk_queue_add+0x28/0xa0 kernel: 4 locks held by swapper/5/0: kernel: #0: (rcu_read_lock){......}, at: [<ffffffff8169ef6b>] netif_receive_skb_internal+0x4b/0x1f0 kernel: #1: (rcu_read_lock){......}, at: [<ffffffff816e977f>] ip_local_deliver_finish+0x3f/0x380 kernel: #2: (slock-AF_INET){+.-...}, at: [<ffffffff81685ffb>] sk_clone_lock+0x19b/0x440 kernel: #3: (&(&queue->rskq_lock)->rlock){+.-...}, at: [<ffffffff816f6a88>] inet_csk_reqsk_queue_add+0x28/0xa0 To properly fix this issue, inet_csk_reqsk_queue_add() needs to return to its callers if the child as been queued into accept queue. We also need to make sure listener is still there before calling sk->sk_data_ready(), by holding a reference on it, since the reference carried by the child can disappear as soon as the child is put on accept queue. Reported-by: Ilya Dryomov <idryomov@gmail.com> Fixes: ebb516af60e1 ("tcp/dccp: fix race at listener dismantle phase") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03route: check and remove route cache when we get routeXin Long
[ Upstream commit deed49df7390d5239024199e249190328f1651e7 ] Since the gc of ipv4 route was removed, the route cached would has no chance to be removed, and even it has been timeout, it still could be used, cause no code to check it's expires. Fix this issue by checking and removing route cache when we get route. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03net:Add sysctl_max_skb_fragsHans Westgaard Ry
[ Upstream commit 5f74f82ea34c0da80ea0b49192bb5ea06e063593 ] Devices may have limits on the number of fragments in an skb they support. Current codebase uses a constant as maximum for number of fragments one skb can hold and use. When enabling scatter/gather and running traffic with many small messages the codebase uses the maximum number of fragments and may thereby violate the max for certain devices. The patch introduces a global variable as max number of fragments. Signed-off-by: Hans Westgaard Ry <hans.westgaard.ry@oracle.com> Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03tcp: do not drop syn_recv on all icmp reportsEric Dumazet
[ Upstream commit 9cf7490360bf2c46a16b7525f899e4970c5fc144 ] Petr Novopashenniy reported that ICMP redirects on SYN_RECV sockets were leading to RST. This is of course incorrect. A specific list of ICMP messages should be able to drop a SYN_RECV. For instance, a REDIRECT on SYN_RECV shall be ignored, as we do not hold a dst per SYN_RECV pseudo request. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111751 Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table") Reported-by: Petr Novopashenniy <pety@rusnet.ru> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03unix: correctly track in-flight fds in sending process user_structHannes Frederic Sowa
[ Upstream commit 415e3d3e90ce9e18727e8843ae343eda5a58fad6 ] The commit referenced in the Fixes tag incorrectly accounted the number of in-flight fds over a unix domain socket to the original opener of the file-descriptor. This allows another process to arbitrary deplete the original file-openers resource limit for the maximum of open files. Instead the sending processes and its struct cred should be credited. To do so, we add a reference counted struct user_struct pointer to the scm_fp_list and use it to account for the number of inflight unix fds. Fixes: 712f4aad406bb1 ("unix: properly account for FDs passed over unix sockets") Reported-by: David Herrmann <dh.herrmann@gmail.com> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03ipv6: enforce flowi6_oif usage in ip6_dst_lookup_tail()Paolo Abeni
[ Upstream commit 6f21c96a78b835259546d8f3fb4edff0f651d478 ] The current implementation of ip6_dst_lookup_tail basically ignore the egress ifindex match: if the saddr is set, ip6_route_output() purposefully ignores flowi6_oif, due to the commit d46a9d678e4c ("net: ipv6: Dont add RT6_LOOKUP_F_IFACE flag if saddr set"), if the saddr is 'any' the first route lookup in ip6_dst_lookup_tail fails, but upon failure a second lookup will be performed with saddr set, thus ignoring the ifindex constraint. This commit adds an output route lookup function variant, which allows the caller to specify lookup flags, and modify ip6_dst_lookup_tail() to enforce the ifindex match on the second lookup via said helper. ip6_route_output() becames now a static inline function build on top of ip6_route_output_flags(); as a side effect, out-of-tree modules need now a GPL license to access the output route lookup functionality. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03gro: Make GRO aware of lightweight tunnels.Jesse Gross
[ Upstream commit ce87fc6ce3f9f4488546187e3757cf666d9d4a2a ] GRO is currently not aware of tunnel metadata generated by lightweight tunnels and stored in the dst. This leads to two possible problems: * Incorrectly merging two frames that have different metadata. * Leaking of allocated metadata from merged frames. This avoids those problems by comparing the tunnel information before merging, similar to how we handle other metadata (such as vlan tags), and releasing any state when we are done. Reported-by: John <john.phillips5@hpe.com> Fixes: 2e15ea39 ("ip_gre: Add support to collect tunnel metadata.") Signed-off-by: Jesse Gross <jesse@kernel.org> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25radix-tree: fix oops after radix_tree_iter_retryKonstantin Khlebnikov
commit 732042821cfa106b3c20b9780e4c60fee9d68900 upstream. Helper radix_tree_iter_retry() resets next_index to the current index. In following radix_tree_next_slot current chunk size becomes zero. This isn't checked and it tries to dereference null pointer in slot. Tagged iterator is fine because retry happens only at slot 0 where tag bitmask in iter->tags is filled with single bit. Fixes: 46437f9a554f ("radix-tree: fix race in gang lookup") Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ohad Ben-Cohen <ohad@wizery.com> Cc: Jeremiah Mahler <jmmahler@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25radix-tree: fix race in gang lookupMatthew Wilcox
commit 46437f9a554fbe3e110580ca08ab703b59f2f95a upstream. If the indirect_ptr bit is set on a slot, that indicates we need to redo the lookup. Introduce a new function radix_tree_iter_retry() which forces the loop to retry the lookup by setting 'slot' to NULL and turning the iterator back to point at the problematic entry. This is a pretty rare problem to hit at the moment; the lookup has to race with a grow of the radix tree from a height of 0. The consequences of hitting this race are that gang lookup could return a pointer to a radix_tree_node instead of a pointer to whatever the user had inserted in the tree. Fixes: cebbd29e1c2f ("radix-tree: rewrite gang lookup using iterator") Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ohad Ben-Cohen <ohad@wizery.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25iommu/vt-d: Clear PPR bit to ensure we get more page request interruptsDavid Woodhouse
commit 46924008273ed03bd11dbb32136e3da4cfe056e1 upstream. According to the VT-d specification we need to clear the PPR bit in the Page Request Status register when handling page requests, or the hardware won't generate any more interrupts. This wasn't actually necessary on SKL/KBL (which may well be the subject of a hardware erratum, although it's harmless enough). But other implementations do appear to get it right, and we only ever get one interrupt unless we clear the PPR bit. Reported-by: CQ Tang <cq.tang@intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25mm: replace vma_lock_anon_vma with anon_vma_lock_read/writeKonstantin Khlebnikov
commit 12352d3cae2cebe18805a91fab34b534d7444231 upstream. Sequence vma_lock_anon_vma() - vma_unlock_anon_vma() isn't safe if anon_vma appeared between lock and unlock. We have to check anon_vma first or call anon_vma_prepare() to be sure that it's here. There are only few users of these legacy helpers. Let's get rid of them. This patch fixes anon_vma lock imbalance in validate_mm(). Write lock isn't required here, read lock is enough. And reorders expand_downwards/expand_upwards: security_mmap_addr() and wrapping-around check don't have to be under anon vma lock. Link: https://lkml.kernel.org/r/CACT4Y+Y908EjM2z=706dv4rV6dWtxTLK9nFg9_7DhRMLppBo2g@mail.gmail.com Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25tracepoints: Do not trace when cpu is offlineSteven Rostedt (Red Hat)
commit f37755490fe9bf76f6ba1d8c6591745d3574a6a6 upstream. The tracepoint infrastructure uses RCU sched protection to enable and disable tracepoints safely. There are some instances where tracepoints are used in infrastructure code (like kfree()) that get called after a CPU is going offline, and perhaps when it is coming back online but hasn't been registered yet. This can probuce the following warning: [ INFO: suspicious RCU usage. ] 4.4.0-00006-g0fe53e8-dirty #34 Tainted: G S ------------------------------- include/trace/events/kmem.h:141 suspicious rcu_dereference_check() usage! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 1, debug_locks = 1 no locks held by swapper/8/0. stack backtrace: CPU: 8 PID: 0 Comm: swapper/8 Tainted: G S 4.4.0-00006-g0fe53e8-dirty #34 Call Trace: [c0000005b76c78d0] [c0000000008b9540] .dump_stack+0x98/0xd4 (unreliable) [c0000005b76c7950] [c00000000010c898] .lockdep_rcu_suspicious+0x108/0x170 [c0000005b76c79e0] [c00000000029adc0] .kfree+0x390/0x440 [c0000005b76c7a80] [c000000000055f74] .destroy_context+0x44/0x100 [c0000005b76c7b00] [c0000000000934a0] .__mmdrop+0x60/0x150 [c0000005b76c7b90] [c0000000000e3ff0] .idle_task_exit+0x130/0x140 [c0000005b76c7c20] [c000000000075804] .pseries_mach_cpu_die+0x64/0x310 [c0000005b76c7cd0] [c000000000043e7c] .cpu_die+0x3c/0x60 [c0000005b76c7d40] [c0000000000188d8] .arch_cpu_idle_dead+0x28/0x40 [c0000005b76c7db0] [c000000000101e6c] .cpu_startup_entry+0x50c/0x560 [c0000005b76c7ed0] [c000000000043bd8] .start_secondary+0x328/0x360 [c0000005b76c7f90] [c000000000008a6c] start_secondary_prolog+0x10/0x14 This warning is not a false positive either. RCU is not protecting code that is being executed while the CPU is offline. Instead of playing "whack-a-mole(TM)" and adding conditional statements to the tracepoints we find that are used in this instance, simply add a cpu_online() test to the tracepoint code where the tracepoint will be ignored if the CPU is offline. Use of raw_smp_processor_id() is fine, as there should never be a case where the tracepoint code goes from running on a CPU that is online and suddenly gets migrated to a CPU that is offline. Link: http://lkml.kernel.org/r/1455387773-4245-1-git-send-email-kda@linux-powerpc.org Reported-by: Denis Kirjanov <kda@linux-powerpc.org> Fixes: 97e1c18e8d17b ("tracing: Kernel Tracepoints") Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25tracing: Fix freak link error caused by branch tracerArnd Bergmann
commit b33c8ff4431a343561e2319f17c14286f2aa52e2 upstream. In my randconfig tests, I came across a bug that involves several components: * gcc-4.9 through at least 5.3 * CONFIG_GCOV_PROFILE_ALL enabling -fprofile-arcs for all files * CONFIG_PROFILE_ALL_BRANCHES overriding every if() * The optimized implementation of do_div() that tries to replace a library call with an division by multiplication * code in drivers/media/dvb-frontends/zl10353.c doing u32 adc_clock = 450560; /* 45.056 MHz */ if (state->config.adc_clock) adc_clock = state->config.adc_clock; do_div(value, adc_clock); In this case, gcc fails to determine whether the divisor in do_div() is __builtin_constant_p(). In particular, it concludes that __builtin_constant_p(adc_clock) is false, while __builtin_constant_p(!!adc_clock) is true. That in turn throws off the logic in do_div() that also uses __builtin_constant_p(), and instead of picking either the constant- optimized division, and the code in ilog2() that uses __builtin_constant_p() to figure out whether it knows the answer at compile time. The result is a link error from failing to find multiple symbols that should never have been called based on the __builtin_constant_p(): dvb-frontends/zl10353.c:138: undefined reference to `____ilog2_NaN' dvb-frontends/zl10353.c:138: undefined reference to `__aeabi_uldivmod' ERROR: "____ilog2_NaN" [drivers/media/dvb-frontends/zl10353.ko] undefined! ERROR: "__aeabi_uldivmod" [drivers/media/dvb-frontends/zl10353.ko] undefined! This patch avoids the problem by changing __trace_if() to check whether the condition is known at compile-time to be nonzero, rather than checking whether it is actually a constant. I see this one link error in roughly one out of 1600 randconfig builds on ARM, and the patch fixes all known instances. Link: http://lkml.kernel.org/r/1455312410-1058841-1-git-send-email-arnd@arndb.de Acked-by: Nicolas Pitre <nico@linaro.org> Fixes: ab3c9c686e22 ("branch tracer, intel-iommu: fix build with CONFIG_BRANCH_TRACER=y") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25ptrace: use fsuid, fsgid, effective creds for fs access checksJann Horn
commit caaee6234d05a58c5b4d05e7bf766131b810a657 upstream. By checking the effective credentials instead of the real UID / permitted capabilities, ensure that the calling process actually intended to use its credentials. To ensure that all ptrace checks use the correct caller credentials (e.g. in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS flag), use two new flags and require one of them to be set. The problem was that when a privileged task had temporarily dropped its privileges, e.g. by calling setreuid(0, user_uid), with the intent to perform following syscalls with the credentials of a user, it still passed ptrace access checks that the user would not be able to pass. While an attacker should not be able to convince the privileged task to perform a ptrace() syscall, this is a problem because the ptrace access check is reused for things in procfs. In particular, the following somewhat interesting procfs entries only rely on ptrace access checks: /proc/$pid/stat - uses the check for determining whether pointers should be visible, useful for bypassing ASLR /proc/$pid/maps - also useful for bypassing ASLR /proc/$pid/cwd - useful for gaining access to restricted directories that contain files with lax permissions, e.g. in this scenario: lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar drwx------ root root /root drwxr-xr-x root root /root/foobar -rw-r--r-- root root /root/foobar/secret Therefore, on a system where a root-owned mode 6755 binary changes its effective credentials as described and then dumps a user-specified file, this could be used by an attacker to reveal the memory layout of root's processes or reveal the contents of files he is not allowed to access (through /proc/$pid/cwd). [akpm@linux-foundation.org: fix warning] Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25pty: make sure super_block is still valid in final /dev/tty closeHerton R. Krzesinski
commit 1f55c718c290616889c04946864a13ef30f64929 upstream. Considering current pty code and multiple devpts instances, it's possible to umount a devpts file system while a program still has /dev/tty opened pointing to a previosuly closed pty pair in that instance. In the case all ptmx and pts/N files are closed, umount can be done. If the program closes /dev/tty after umount is done, devpts_kill_index will use now an invalid super_block, which was already destroyed in the umount operation after running ->kill_sb. This is another "use after free" type of issue, but now related to the allocated super_block instance. To avoid the problem (warning at ida_remove and potential crashes) for this specific case, I added two functions in devpts which grabs additional references to the super_block, which pty code now uses so it makes sure the super block structure is still valid until pty shutdown is done. I also moved the additional inode references to the same functions, which also covered similar case with inode being freed before /dev/tty final close/shutdown. Signed-off-by: Herton R. Krzesinski <herton@redhat.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-17crypto: af_alg - Allow af_af_alg_release_parent to be called on nokey pathHerbert Xu
commit 6a935170a980024dd29199e9dbb5c4da4767a1b9 upstream. This patch allows af_alg_release_parent to be called even for nokey sockets. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-17crypto: skcipher - Add crypto_skcipher_has_setkeyHerbert Xu
commit a1383cd86a062fc798899ab20f0ec2116cce39cb upstream. This patch adds a way for skcipher users to determine whether a key is required by a transform. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-17crypto: hash - Add crypto_ahash_has_setkeyHerbert Xu
commit a5596d6332787fd383b3b5427b41f94254430827 upstream. This patch adds a way for ahash users to determine whether a key is required by a crypto_ahash transform. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-17crypto: af_alg - Add nokey compatibility pathHerbert Xu
commit 37766586c965d63758ad542325a96d5384f4a8c9 upstream. This patch adds a compatibility path to support old applications that do acept(2) before setkey. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-17crypto: af_alg - Disallow bind/setkey/... after accept(2)Herbert Xu
commit c840ac6af3f8713a71b4d2363419145760bd6044 upstream. Each af_alg parent socket obtained by socket(2) corresponds to a tfm object once bind(2) has succeeded. An accept(2) call on that parent socket creates a context which then uses the tfm object. Therefore as long as any child sockets created by accept(2) exist the parent socket must not be modified or freed. This patch guarantees this by using locks and a reference count on the parent socket. Any attempt to modify the parent socket will fail with EBUSY. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-17tty: Wait interruptibly for tty lock on reopenPeter Hurley
commit 0bfd464d3fdd5bb322f9cace4cc47f1796545cf7 upstream. Allow a signal to interrupt the wait for a tty reopen; eg., if the tty has starting final close and is waiting for the device to drain. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>