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2019-04-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller21-43/+171
Two easy cases of overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-23Merge tag 'nfsd-5.1-1' of git://linux-nfs.org/~bfields/linuxLinus Torvalds5-7/+42
Pull nfsd bugfixes from Bruce Fields: "Fix miscellaneous nfsd bugs, in NFSv4.1 callbacks, NFSv4.1 lock-notification callbacks, NFSv3 readdir encoding, and the cache/upcall code" * tag 'nfsd-5.1-1' of git://linux-nfs.org/~bfields/linux: nfsd: wake blocked file lock waiters before sending callback nfsd: wake waiters blocked on file_lock before deleting it nfsd: Don't release the callback slot unless it was actually held nfsd/nfsd3_proc_readdir: fix buffer count and page pointers sunrpc: don't mark uninitialised items as VALID.
2019-04-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller1-4/+21
Alexei Starovoitov says: ==================== pull-request: bpf-next 2019-04-22 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) allow stack/queue helpers from more bpf program types, from Alban. 2) allow parallel verification of root bpf programs, from Alexei. 3) introduce bpf sysctl hook for trusted root cases, from Andrey. 4) recognize var/datasec in btf deduplication, from Andrii. 5) cpumap performance optimizations, from Jesper. 6) verifier prep for alu32 optimization, from Jiong. 7) libbpf xsk cleanup, from Magnus. 8) other various fixes and cleanups. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-22nfsd: wake blocked file lock waiters before sending callbackJeff Layton1-0/+9
When a blocked NFS lock is "awoken" we send a callback to the server and then wake any hosts waiting on it. If a client attempts to get a lock and then drops off the net, we could end up waiting for a long time until we end up waking locks blocked on that request. So, wake any other waiting lock requests before sending the callback. Do this by calling locks_delete_block in a new "prepare" phase for CB_NOTIFY_LOCK callbacks. URL: https://bugzilla.kernel.org/show_bug.cgi?id=203363 Fixes: 16306a61d3b7 ("fs/locks: always delete_block after waiting.") Reported-by: Slawomir Pryczek <slawek1211@gmail.com> Cc: Neil Brown <neilb@suse.com> Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-04-22nfsd: wake waiters blocked on file_lock before deleting itJeff Layton1-2/+1
After a blocked nfsd file_lock request is deleted, knfsd will send a callback to the client and then free the request. Commit 16306a61d3b7 ("fs/locks: always delete_block after waiting.") changed it such that locks_delete_block is always called on a request after it is awoken, but that patch missed fixing up blocked nfsd request handling. Call locks_delete_block on the block to wake up any locks still blocked on the nfsd lock request before freeing it. Some of its callers already do this however, so just remove those calls. URL: https://bugzilla.kernel.org/show_bug.cgi?id=203363 Fixes: 16306a61d3b7 ("fs/locks: always delete_block after waiting.") Reported-by: Slawomir Pryczek <slawek1211@gmail.com> Cc: Neil Brown <neilb@suse.com> Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-04-20Merge tag 'for-linus-20190420' of git://git.kernel.dk/linux-blockLinus Torvalds1-11/+30
Pull block fixes from Jens Axboe: "A set of small fixes that should go into this series. This contains: - Removal of unused queue member (Hou) - Overflow bvec fix (Ming) - Various little io_uring tweaks (me) - kthread parking - Only call cpu_possible() for verified CPU - Drop unused 'file' argument to io_file_put() - io_uring_enter vs io_uring_register deadlock fix - CQ overflow fix - BFQ internal depth update fix (me)" * tag 'for-linus-20190420' of git://git.kernel.dk/linux-block: block: make sure that bvec length can't be overflow block: kill all_q_node in request_queue io_uring: fix CQ overflow condition io_uring: fix possible deadlock between io_uring_{enter,register} io_uring: drop io_file_put() 'file' argument bfq: update internal depth state when queue depth changes io_uring: only test SQPOLL cpu after we've verified it io_uring: park SQPOLL thread if it's percpu
2019-04-19coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumpingAndrea Arcangeli2-0/+27
The core dumping code has always run without holding the mmap_sem for writing, despite that is the only way to ensure that the entire vma layout will not change from under it. Only using some signal serialization on the processes belonging to the mm is not nearly enough. This was pointed out earlier. For example in Hugh's post from Jul 2017: https://lkml.kernel.org/r/alpine.LSU.2.11.1707191716030.2055@eggly.anvils "Not strictly relevant here, but a related note: I was very surprised to discover, only quite recently, how handle_mm_fault() may be called without down_read(mmap_sem) - when core dumping. That seems a misguided optimization to me, which would also be nice to correct" In particular because the growsdown and growsup can move the vm_start/vm_end the various loops the core dump does around the vma will not be consistent if page faults can happen concurrently. Pretty much all users calling mmget_not_zero()/get_task_mm() and then taking the mmap_sem had the potential to introduce unexpected side effects in the core dumping code. Adding mmap_sem for writing around the ->core_dump invocation is a viable long term fix, but it requires removing all copy user and page faults and to replace them with get_dump_page() for all binary formats which is not suitable as a short term fix. For the time being this solution manually covers the places that can confuse the core dump either by altering the vma layout or the vma flags while it runs. Once ->core_dump runs under mmap_sem for writing the function mmget_still_valid() can be dropped. Allowing mmap_sem protected sections to run in parallel with the coredump provides some minor parallelism advantage to the swapoff code (which seems to be safe enough by never mangling any vma field and can keep doing swapins in parallel to the core dumping) and to some other corner case. In order to facilitate the backporting I added "Fixes: 86039bd3b4e6" however the side effect of this same race condition in /proc/pid/mem should be reproducible since before 2.6.12-rc2 so I couldn't add any other "Fixes:" because there's no hash beyond the git genesis commit. Because find_extend_vma() is the only location outside of the process context that could modify the "mm" structures under mmap_sem for reading, by adding the mmget_still_valid() check to it, all other cases that take the mmap_sem for reading don't need the new check after mmget_not_zero()/get_task_mm(). The expand_stack() in page fault context also doesn't need the new check, because all tasks under core dumping are frozen. Link: http://lkml.kernel.org/r/20190325224949.11068-1-aarcange@redhat.com Fixes: 86039bd3b4e6 ("userfaultfd: add new syscall to provide memory externalization") Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Jann Horn <jannh@google.com> Suggested-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Xu <peterx@redhat.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Jann Horn <jannh@google.com> Acked-by: Jason Gunthorpe <jgg@mellanox.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-18Merge tag 'afs-fixes-20190413' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fsLinus Torvalds7-11/+10
Pull AFS fixes from David Howells: - Stop using the deprecated get_seconds(). - Don't make tracepoint strings const as the section they go in isn't read-only. - Differentiate failure due to unmarshalling from other failure cases. We shouldn't abort with RXGEN_CC/SS_UNMARSHAL if it's not due to unmarshalling. - Add a missing unlock_page(). - Fix the interaction between receiving a notification from a server that it has invalidated all outstanding callback promises and a client call that we're in the middle of making that will get a new promise. * tag 'afs-fixes-20190413' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: afs: Fix in-progess ops to ignore server-level callback invalidation afs: Unlock pages for __pagevec_release() afs: Differentiate abort due to unmarshalling from other errors afs: Avoid section confusion in CM_NAME afs: avoid deprecated get_seconds()
2019-04-17Merge tag '5.1-rc5-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds6-14/+62
Pull smb3 fixes from Steve French: "Five small SMB3 fixes, all also for stable - an important fix for an oplock (lease) bug, a handle leak, and three bugs spotted by KASAN" * tag '5.1-rc5-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: CIFS: keep FileInfo handle live during oplock break cifs: fix handle leak in smb2_query_symlink() cifs: Fix lease buffer length error cifs: Fix use-after-free in SMB2_read cifs: Fix use-after-free in SMB2_write
2019-04-17io_uring: fix CQ overflow conditionJens Axboe1-1/+1
This is a leftover from when the rings initially were not free flowing, and hence a test for tail + 1 == head would indicate full. Since we now let them wrap instead of mask them with the size, we need to check if they drift more than the ring size from each other. This fixes a case where we'd overwrite CQ ring entries, if the user failed to reap completions. Both cases would ultimately result in lost completions as the application violated the depth it asked for. The only difference is that before this fix we'd return invalid entries for the overflowed completions, instead of properly flagging it in the cq_ring->overflow variable. Reported-by: Stefan Bühler <source@stbuehler.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds1-7/+17
Pull networking fixes from David Miller: 1) Handle init flow failures properly in iwlwifi driver, from Shahar S Matityahu. 2) mac80211 TXQs need to be unscheduled on powersave start, from Felix Fietkau. 3) SKB memory accounting fix in A-MDSU aggregation, from Felix Fietkau. 4) Increase RCU lock hold time in mlx5 FPGA code, from Saeed Mahameed. 5) Avoid checksum complete with XDP in mlx5, also from Saeed. 6) Fix netdev feature clobbering in ibmvnic driver, from Thomas Falcon. 7) Partial sent TLS record leak fix from Jakub Kicinski. 8) Reject zero size iova range in vhost, from Jason Wang. 9) Allow pending work to complete before clcsock release from Karsten Graul. 10) Fix XDP handling max MTU in thunderx, from Matteo Croce. 11) A lot of protocols look at the sa_family field of a sockaddr before validating it's length is large enough, from Tetsuo Handa. 12) Don't write to free'd pointer in qede ptp error path, from Colin Ian King. 13) Have to recompile IP options in ipv4_link_failure because it can be invoked from ARP, from Stephen Suryaputra. 14) Doorbell handling fixes in qed from Denis Bolotin. 15) Revert net-sysfs kobject register leak fix, it causes new problems. From Wang Hai. 16) Spectre v1 fix in ATM code, from Gustavo A. R. Silva. 17) Fix put of BROPT_VLAN_STATS_PER_PORT in bridging code, from Nikolay Aleksandrov. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (111 commits) socket: fix compat SO_RCVTIMEO_NEW/SO_SNDTIMEO_NEW tcp: tcp_grow_window() needs to respect tcp_space() ocelot: Clean up stats update deferred work ocelot: Don't sleep in atomic context (irqs_disabled()) net: bridge: fix netlink export of vlan_stats_per_port option qed: fix spelling mistake "faspath" -> "fastpath" tipc: set sysctl_tipc_rmem and named_timeout right range tipc: fix link established but not in session net: Fix missing meta data in skb with vlan packet net: atm: Fix potential Spectre v1 vulnerabilities net/core: work around section mismatch warning for ptp_classifier net: bridge: fix per-port af_packet sockets bnx2x: fix spelling mistake "dicline" -> "decline" route: Avoid crash from dereferencing NULL rt->from MAINTAINERS: normalize Woojung Huh's email address bonding: fix event handling for stacked bonds Revert "net-sysfs: Fix memory leak in netdev_register_kobject" rtnetlink: fix rtnl_valid_stats_req() nlmsg_len check qed: Fix the DORQ's attentions handling qed: Fix missing DORQ attentions ...
2019-04-16CIFS: keep FileInfo handle live during oplock breakAurelien Aptel4-10/+53
In the oplock break handler, writing pending changes from pages puts the FileInfo handle. If the refcount reaches zero it closes the handle and waits for any oplock break handler to return, thus causing a deadlock. To prevent this situation: * We add a wait flag to cifsFileInfo_put() to decide whether we should wait for running/pending oplock break handlers * We keep an additionnal reference of the SMB FileInfo handle so that for the rest of the handler putting the handle won't close it. - The ref is bumped everytime we queue the handler via the cifs_queue_oplock_break() helper. - The ref is decremented at the end of the handler This bug was triggered by xfstest 464. Also important fix to address the various reports of oops in smb2_push_mandatory_locks Signed-off-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> CC: Stable <stable@vger.kernel.org>
2019-04-16cifs: fix handle leak in smb2_query_symlink()Ronnie Sahlberg1-0/+2
If we enter smb2_query_symlink() for something that is not a symlink and where the SMB2_open() would succeed we would never end up closing this handle and would thus leak a handle on the server. Fix this by immediately calling SMB2_close() on successfull open. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> CC: Stable <stable@vger.kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-04-16cifs: Fix lease buffer length errorZhangXiaoxu1-1/+4
There is a KASAN slab-out-of-bounds: BUG: KASAN: slab-out-of-bounds in _copy_from_iter_full+0x783/0xaa0 Read of size 80 at addr ffff88810c35e180 by task mount.cifs/539 CPU: 1 PID: 539 Comm: mount.cifs Not tainted 4.19 #10 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0xdd/0x12a print_address_description+0xa7/0x540 kasan_report+0x1ff/0x550 check_memory_region+0x2f1/0x310 memcpy+0x2f/0x80 _copy_from_iter_full+0x783/0xaa0 tcp_sendmsg_locked+0x1840/0x4140 tcp_sendmsg+0x37/0x60 inet_sendmsg+0x18c/0x490 sock_sendmsg+0xae/0x130 smb_send_kvec+0x29c/0x520 __smb_send_rqst+0x3ef/0xc60 smb_send_rqst+0x25a/0x2e0 compound_send_recv+0x9e8/0x2af0 cifs_send_recv+0x24/0x30 SMB2_open+0x35e/0x1620 open_shroot+0x27b/0x490 smb2_open_op_close+0x4e1/0x590 smb2_query_path_info+0x2ac/0x650 cifs_get_inode_info+0x1058/0x28f0 cifs_root_iget+0x3bb/0xf80 cifs_smb3_do_mount+0xe00/0x14c0 cifs_do_mount+0x15/0x20 mount_fs+0x5e/0x290 vfs_kern_mount+0x88/0x460 do_mount+0x398/0x31e0 ksys_mount+0xc6/0x150 __x64_sys_mount+0xea/0x190 do_syscall_64+0x122/0x590 entry_SYSCALL_64_after_hwframe+0x44/0xa9 It can be reproduced by the following step: 1. samba configured with: server max protocol = SMB2_10 2. mount -o vers=default When parse the mount version parameter, the 'ops' and 'vals' was setted to smb30, if negotiate result is smb21, just update the 'ops' to smb21, but the 'vals' is still smb30. When add lease context, the iov_base is allocated with smb21 ops, but the iov_len is initiallited with the smb30. Because the iov_len is longer than iov_base, when send the message, copy array out of bounds. we need to keep the 'ops' and 'vals' consistent. Fixes: 9764c02fcbad ("SMB3: Add support for multidialect negotiate (SMB2.1 and later)") Fixes: d5c7076b772a ("smb3: add smb3.1.1 to default dialect list") Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com> CC: Stable <stable@vger.kernel.org> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-04-16cifs: Fix use-after-free in SMB2_readZhangXiaoxu1-2/+2
There is a KASAN use-after-free: BUG: KASAN: use-after-free in SMB2_read+0x1136/0x1190 Read of size 8 at addr ffff8880b4e45e50 by task ln/1009 Should not release the 'req' because it will use in the trace. Fixes: eccb4422cf97 ("smb3: Add ftrace tracepoints for improved SMB3 debugging") Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com> CC: Stable <stable@vger.kernel.org> 4.18+ Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-04-16cifs: Fix use-after-free in SMB2_writeZhangXiaoxu1-1/+1
There is a KASAN use-after-free: BUG: KASAN: use-after-free in SMB2_write+0x1342/0x1580 Read of size 8 at addr ffff8880b6a8e450 by task ln/4196 Should not release the 'req' because it will use in the trace. Fixes: eccb4422cf97 ("smb3: Add ftrace tracepoints for improved SMB3 debugging") Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com> CC: Stable <stable@vger.kernel.org> 4.18+ Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-04-15Merge tag 'fsdax-fix-5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimmLinus Torvalds1-0/+15
Pull fsdax fix from Dan Williams: "A single filesystem-dax fix. It has been lingering in -next for a long while and there are no other fsdax fixes on the horizon: - Avoid a crash scenario with architectures like powerpc that require 'pgtable_deposit' for the zero page" * tag 'fsdax-fix-5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: fs/dax: Deposit pagetable even when installing zero page
2019-04-15io_uring: fix possible deadlock between io_uring_{enter,register}Jens Axboe1-0/+12
If we have multiple threads, one doing io_uring_enter() while the other is doing io_uring_register(), we can run into a deadlock between the two. io_uring_register() must wait for existing users of the io_uring instance to exit. But it does so while holding the io_uring mutex. Callers of io_uring_enter() may need this mutex to make progress (and eventually exit). If we wait for users to exit in io_uring_register(), we can't do so with the io_uring mutex held without potentially risking a deadlock. Drop the io_uring mutex while waiting for existing callers to exit. This is safe and guaranteed to make forward progress, since we already killed the percpu ref before doing so. Hence later callers of io_uring_enter() will be rejected. Reported-by: syzbot+16dc03452dee970a0c3e@syzkaller.appspotmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-14Merge branch 'page-refs' (page ref overflow)Linus Torvalds3-10/+18
Merge page ref overflow branch. Jann Horn reported that he can overflow the page ref count with sufficient memory (and a filesystem that is intentionally extremely slow). Admittedly it's not exactly easy. To have more than four billion references to a page requires a minimum of 32GB of kernel memory just for the pointers to the pages, much less any metadata to keep track of those pointers. Jann needed a total of 140GB of memory and a specially crafted filesystem that leaves all reads pending (in order to not ever free the page references and just keep adding more). Still, we have a fairly straightforward way to limit the two obvious user-controllable sources of page references: direct-IO like page references gotten through get_user_pages(), and the splice pipe page duplication. So let's just do that. * branch page-refs: fs: prevent page refcount overflow in pipe_buf_get mm: prevent get_user_pages() from overflowing page refcount mm: add 'try_get_page()' helper function mm: make page ref count overflow check tighter and more explicit
2019-04-14fs: prevent page refcount overflow in pipe_buf_getMatthew Wilcox3-10/+18
Change pipe_buf_get() to return a bool indicating whether it succeeded in raising the refcount of the page (if the thing in the pipe is a page). This removes another mechanism for overflowing the page refcount. All callers converted to handle a failure. Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Matthew Wilcox <willy@infradead.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-13io_uring: drop io_file_put() 'file' argumentJens Axboe1-6/+4
Since the fget/fput handling was reworked in commit 09bb839434bd, we never call io_file_put() with state == NULL (and hence file != NULL) anymore. Remove that case. Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-13io_uring: only test SQPOLL cpu after we've verified itJens Axboe1-4/+8
We currently call cpu_possible() even if we don't use the CPU. Move the test under the SQ_AFF branch, which is the only place where we'll use the value. Do the cpu_possible() test AFTER we've limited it to a max of NR_CPUS. This avoids triggering the following warning: WARNING: CPU: 1 PID: 7600 at include/linux/cpumask.h:121 cpu_max_bits_warn if CONFIG_DEBUG_PER_CPU_MAPS is enabled. While in there, also move the SQ thread idle period assignment inside SETUP_SQPOLL, as we don't use it otherwise either. Reported-by: syzbot+cd714a07c6de2bc34293@syzkaller.appspotmail.com Fixes: 6c271ce2f1d5 ("io_uring: add submission polling") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-13io_uring: park SQPOLL thread if it's percpuJens Axboe1-0/+5
kthread expects this, or we can throw a warning on exit: WARNING: CPU: 0 PID: 7822 at kernel/kthread.c:399 __kthread_bind_mask+0x3b/0xc0 kernel/kthread.c:399 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 7822 Comm: syz-executor030 Not tainted 5.1.0-rc4-next-20190412 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 panic+0x2cb/0x72b kernel/panic.c:214 __warn.cold+0x20/0x46 kernel/panic.c:576 report_bug+0x263/0x2b0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:179 [inline] fixup_bug arch/x86/kernel/traps.c:174 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973 RIP: 0010:__kthread_bind_mask+0x3b/0xc0 kernel/kthread.c:399 Code: 48 89 fb e8 f7 ab 24 00 4c 89 e6 48 89 df e8 ac e1 02 00 31 ff 49 89 c4 48 89 c6 e8 7f ad 24 00 4d 85 e4 75 15 e8 d5 ab 24 00 <0f> 0b e8 ce ab 24 00 5b 41 5c 41 5d 41 5e 5d c3 e8 c0 ab 24 00 4c RSP: 0018:ffff8880a89bfbb8 EFLAGS: 00010293 RAX: ffff88808ca7a280 RBX: ffff8880a98e4380 RCX: ffffffff814bdd11 RDX: 0000000000000000 RSI: ffffffff814bdd1b RDI: 0000000000000007 RBP: ffff8880a89bfbd8 R08: ffff88808ca7a280 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff87691148 R14: ffff8880a98e43a0 R15: ffffffff81c91e10 __kthread_bind kernel/kthread.c:412 [inline] kthread_unpark+0x123/0x160 kernel/kthread.c:480 kthread_stop+0xfa/0x6c0 kernel/kthread.c:556 io_sq_thread_stop fs/io_uring.c:2057 [inline] io_sq_thread_stop fs/io_uring.c:2052 [inline] io_finish_async+0xab/0x180 fs/io_uring.c:2064 io_ring_ctx_free fs/io_uring.c:2534 [inline] io_ring_ctx_wait_and_kill+0x133/0x510 fs/io_uring.c:2591 io_uring_release+0x42/0x50 fs/io_uring.c:2599 __fput+0x2e5/0x8d0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x90a/0x2fa0 kernel/exit.c:876 do_group_exit+0x135/0x370 kernel/exit.c:980 __do_sys_exit_group kernel/exit.c:991 [inline] __se_sys_exit_group kernel/exit.c:989 [inline] __x64_sys_exit_group+0x44/0x50 kernel/exit.c:989 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Reported-by: syzbot+6d4a92619eb0ad08602b@syzkaller.appspotmail.com Fixes: 6c271ce2f1d5 ("io_uring: add submission polling") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-13Merge tag 'for-linus-20190412' of git://git.kernel.dk/linux-blockLinus Torvalds2-4/+8
Pull block fixes from Jens Axboe: "Set of fixes that should go into this round. This pull is larger than I'd like at this time, but there's really no specific reason for that. Some are fixes for issues that went into this merge window, others are not. Anyway, this contains: - Hardware queue limiting for virtio-blk/scsi (Dongli) - Multi-page bvec fixes for lightnvm pblk - Multi-bio dio error fix (Jason) - Remove the cache hint from the io_uring tool side, since we didn't move forward with that (me) - Make io_uring SETUP_SQPOLL root restricted (me) - Fix leak of page in error handling for pc requests (Jérôme) - Fix BFQ regression introduced in this merge window (Paolo) - Fix break logic for bio segment iteration (Ming) - Fix NVMe cancel request error handling (Ming) - NVMe pull request with two fixes (Christoph): - fix the initial CSN for nvme-fc (James) - handle log page offsets properly in the target (Keith)" * tag 'for-linus-20190412' of git://git.kernel.dk/linux-block: block: fix the return errno for direct IO nvmet: fix discover log page when offsets are used nvme-fc: correct csn initialization and increments on error block: do not leak memory in bio_copy_user_iov() lightnvm: pblk: fix crash in pblk_end_partial_read due to multipage bvecs nvme: cancel request synchronously blk-mq: introduce blk_mq_complete_request_sync() scsi: virtio_scsi: limit number of hw queues by nr_cpu_ids virtio-blk: limit number of hw queues by nr_cpu_ids block, bfq: fix use after free in bfq_bfqq_expire io_uring: restrict IORING_SETUP_SQPOLL to root tools/io_uring: remove IOCQE_FLAG_CACHEHIT block: don't use for-inside-for in bio_for_each_segment_all
2019-04-13Merge tag 'nfs-for-5.1-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds4-7/+7
Pull NFS client bugfixes from Trond Myklebust: "Highlights include: Stable fix: - Fix a deadlock in close() due to incorrect draining of RDMA queues Bugfixes: - Revert "SUNRPC: Micro-optimise when the task is known not to be sleeping" as it is causing stack overflows - Fix a regression where NFSv4 getacl and fs_locations stopped working - Forbid setting AF_INET6 to "struct sockaddr_in"->sin_family. - Fix xfstests failures due to incorrect copy_file_range() return values" * tag 'nfs-for-5.1-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: Revert "SUNRPC: Micro-optimise when the task is known not to be sleeping" NFSv4.1 fix incorrect return value in copy_file_range xprtrdma: Fix helper that drains the transport NFS: Fix handling of reply page vector NFS: Forbid setting AF_INET6 to "struct sockaddr_in"->sin_family.
2019-04-13afs: Fix in-progess ops to ignore server-level callback invalidationDavid Howells3-6/+2
The in-kernel afs filesystem client counts the number of server-level callback invalidation events (CB.InitCallBackState* RPC operations) that it receives from the server. This is stored in cb_s_break in various structures, including afs_server and afs_vnode. If an inode is examined by afs_validate(), say, the afs_server copy is compared, along with other break counters, to those in afs_vnode, and if one or more of the counters do not match, it is considered that the server's callback promise is broken. At points where this happens, AFS_VNODE_CB_PROMISED is cleared to indicate that the status must be refetched from the server. afs_validate() issues an FS.FetchStatus operation to get updated metadata - and based on the updated data_version may invalidate the pagecache too. However, the break counters are also used to determine whether to note a new callback in the vnode (which would set the AFS_VNODE_CB_PROMISED flag) and whether to cache the permit data included in the YFSFetchStatus record by the server. The problem comes when the server sends us a CB.InitCallBackState op. The first such instance doesn't cause cb_s_break to be incremented, but rather causes AFS_SERVER_FL_NEW to be cleared - but thereafter, say some hours after last use and all the volumes have been automatically unmounted and the server has forgotten about the client[*], this *will* likely cause an increment. [*] There are other circumstances too, such as the server restarting or needing to make space in its callback table. Note that the server won't send us a CB.InitCallBackState op until we talk to it again. So what happens is: (1) A mount for a new volume is attempted, a inode is created for the root vnode and vnode->cb_s_break and AFS_VNODE_CB_PROMISED aren't set immediately, as we don't have a nominated server to talk to yet - and we may iterate through a few to find one. (2) Before the operation happens, afs_fetch_status(), say, notes in the cursor (fc.cb_break) the break counter sum from the vnode, volume and server counters, but the server->cb_s_break is currently 0. (3) We send FS.FetchStatus to the server. The server sends us back CB.InitCallBackState. We increment server->cb_s_break. (4) Our FS.FetchStatus completes. The reply includes a callback record. (5) xdr_decode_AFSCallBack()/xdr_decode_YFSCallBack() check to see whether the callback promise was broken by checking the break counter sum from step (2) against the current sum. This fails because of step (3), so we don't set the callback record and, importantly, don't set AFS_VNODE_CB_PROMISED on the vnode. This does not preclude the syscall from progressing, and we don't loop here rechecking the status, but rather assume it's good enough for one round only and will need to be rechecked next time. (6) afs_validate() it triggered on the vnode, probably called from d_revalidate() checking the parent directory. (7) afs_validate() notes that AFS_VNODE_CB_PROMISED isn't set, so doesn't update vnode->cb_s_break and assumes the vnode to be invalid. (8) afs_validate() needs to calls afs_fetch_status(). Go back to step (2) and repeat, every time the vnode is validated. This primarily affects volume root dir vnodes. Everything subsequent to those inherit an already incremented cb_s_break upon mounting. The issue is that we assume that the callback record and the cached permit information in a reply from the server can't be trusted after getting a server break - but this is wrong since the server makes sure things are done in the right order, holding up our ops if necessary[*]. [*] There is an extremely unlikely scenario where a reply from before the CB.InitCallBackState could get its delivery deferred till after - at which point we think we have a promise when we don't. This, however, requires unlucky mass packet loss to one call. AFS_SERVER_FL_NEW tries to paper over the cracks for the initial mount from a server we've never contacted before, but this should be unnecessary. It's also further insulated from the problem on an initial mount by querying the server first with FS.GetCapabilities, which triggers the CB.InitCallBackState. Fix this by (1) Remove AFS_SERVER_FL_NEW. (2) In afs_calc_vnode_cb_break(), don't include cb_s_break in the calculation. (3) In afs_cb_is_broken(), don't include cb_s_break in the check. Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-13afs: Unlock pages for __pagevec_release()Marc Dionne1-0/+1
__pagevec_release() complains loudly if any page in the vector is still locked. The pages need to be locked for generic_error_remove_page(), but that function doesn't actually unlock them. Unlock the pages afterwards. Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Jonathan Billings <jsbillin@umich.edu>
2019-04-13afs: Differentiate abort due to unmarshalling from other errorsDavid Howells1-1/+5
Differentiate an abort due to an unmarshalling error from an abort due to other errors, such as ENETUNREACH. It doesn't make sense to set abort code RXGEN_*_UNMARSHAL in such a case, so use RX_USER_ABORT instead. Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-13afs: Avoid section confusion in CM_NAMEAndi Kleen1-1/+1
__tracepoint_str cannot be const because the tracepoint_str section is not read-only. Remove the stray const. Cc: dhowells@redhat.com Cc: viro@zeniv.linux.org.uk Signed-off-by: Andi Kleen <ak@linux.intel.com>
2019-04-13afs: avoid deprecated get_seconds()Arnd Bergmann1-3/+1
get_seconds() has a limited range on 32-bit architectures and is deprecated because of that. While AFS uses the same limits for its inode timestamps on the wire protocol, let's just use the simpler current_time() as we do for other file systems. This will still zero out the 'tv_nsec' field of the timestamps internally. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-12afs: Check for rxrpc call completion in wait loopMarc Dionne1-6/+16
Check the state of the rxrpc call backing an afs call in each iteration of the call wait loop in case the rxrpc call has already been terminated at the rxrpc layer. Interrupt the wait loop and mark the afs call as complete if the rxrpc layer call is complete. There were cases where rxrpc errors were not passed up to afs, which could result in this loop waiting forever for an afs call to transition to AFS_CALL_COMPLETE while the rx call was already complete. Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-12rxrpc: Make rxrpc_kernel_check_life() indicate if call completedMarc Dionne1-2/+2
Make rxrpc_kernel_check_life() pass back the life counter through the argument list and return true if the call has not yet completed. Suggested-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-12bpf: Add file_pos field to bpf_sysctl ctxAndrey Ignatov1-1/+1
Add file_pos field to bpf_sysctl context to read and write sysctl file position at which sysctl is being accessed (read or written). The field can be used to e.g. override whole sysctl value on write to sysctl even when sys_write is called by user space with file_pos > 0. Or BPF program may reject such accesses. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12bpf: Introduce bpf_sysctl_{get,set}_new_value helpersAndrey Ignatov1-5/+17
Add helpers to work with new value being written to sysctl by user space. bpf_sysctl_get_new_value() copies value being written to sysctl into provided buffer. bpf_sysctl_set_new_value() overrides new value being written by user space with a one from provided buffer. Buffer should contain string representation of the value, similar to what can be seen in /proc/sys/. Both helpers can be used only on sysctl write. File position matters and can be managed by an interface that will be introduced separately. E.g. if user space calls sys_write to a file in /proc/sys/ at file position = X, where X > 0, then the value set by bpf_sysctl_set_new_value() will be written starting from X. If program wants to override whole value with specified buffer, file position has to be set to zero. Documentation for the new helpers is provided in bpf.h UAPI. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12bpf: Sysctl hookAndrey Ignatov1-0/+5
Containerized applications may run as root and it may create problems for whole host. Specifically such applications may change a sysctl and affect applications in other containers. Furthermore in existing infrastructure it may not be possible to just completely disable writing to sysctl, instead such a process should be gradual with ability to log what sysctl are being changed by a container, investigate, limit the set of writable sysctl to currently used ones (so that new ones can not be changed) and eventually reduce this set to zero. The patch introduces new program type BPF_PROG_TYPE_CGROUP_SYSCTL and attach type BPF_CGROUP_SYSCTL to solve these problems on cgroup basis. New program type has access to following minimal context: struct bpf_sysctl { __u32 write; }; Where @write indicates whether sysctl is being read (= 0) or written (= 1). Helpers to access sysctl name and value will be introduced separately. BPF_CGROUP_SYSCTL attach point is added to sysctl code right before passing control to ctl_table->proc_handler so that BPF program can either allow or deny access to sysctl. Suggested-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-11block: fix the return errno for direct IOJason Yan1-4/+4
If the last bio returned is not dio->bio, the status of the bio will not assigned to dio->bio if it is error. This will cause the whole IO status wrong. ksoftirqd/21-117 [021] ..s. 4017.966090: 8,0 C N 4883648 [0] <idle>-0 [018] ..s. 4017.970888: 8,0 C WS 4924800 + 1024 [0] <idle>-0 [018] ..s. 4017.970909: 8,0 D WS 4935424 + 1024 [<idle>] <idle>-0 [018] ..s. 4017.970924: 8,0 D WS 4936448 + 321 [<idle>] ksoftirqd/21-117 [021] ..s. 4017.995033: 8,0 C R 4883648 + 336 [65475] ksoftirqd/21-117 [021] d.s. 4018.001988: myprobe1: (blkdev_bio_end_io+0x0/0x168) bi_status=7 ksoftirqd/21-117 [021] d.s. 4018.001992: myprobe: (aio_complete_rw+0x0/0x148) x0=0xffff802f2595ad80 res=0x12a000 res2=0x0 We always have to assign bio->bi_status to dio->bio.bi_status because we will only check dio->bio.bi_status when we return the whole IO to the upper layer. Fixes: 542ff7bf18c6 ("block: new direct I/O implementation") Cc: stable@vger.kernel.org Cc: Christoph Hellwig <hch@lst.de> Cc: Jens Axboe <axboe@kernel.dk> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-11Merge tag 'for-5.1-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linuxLinus Torvalds2-4/+14
Pull btrfs fixes from David Sterba: - fix parsing of compression algorithm when set as a inode property, this could end up with eg. 'zst' or 'zli' in the value - don't allow trim on a filesystem with unreplayed log, this could cause data loss if there are pending updates to the block groups that would not be subject to trim after replay * tag 'for-5.1-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: prop: fix vanished compression property after failed set btrfs: prop: fix zstd compression parameter validation Btrfs: do not allow trimming when a fs is mounted with the nologreplay option
2019-04-11NFSv4.1 fix incorrect return value in copy_file_rangeOlga Kornievskaia2-4/+3
According to the NFSv4.2 spec if the input and output file is the same file, operation should fail with EINVAL. However, linux copy_file_range() system call has no such restrictions. Therefore, in such case let's return EOPNOTSUPP and allow VFS to fallback to doing do_splice_direct(). Also when copy_file_range is called on an NFSv4.0 or 4.1 mount (ie., a server that doesn't support COPY functionality), we also need to return EOPNOTSUPP and fallback to a regular copy. Fixes xfstest generic/075, generic/091, generic/112, generic/263 for all NFSv4.x versions. Signed-off-by: Olga Kornievskaia <kolga@netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-04-11NFS: Fix handling of reply page vectorChuck Lever1-2/+2
NFSv4 GETACL and FS_LOCATIONS requests stopped working in v5.1-rc. These two need the extra padding to be added directly to the reply length. Reported-by: Olga Kornievskaia <aglo@umich.edu> Fixes: 02ef04e432ba ("NFS: Account for XDR pad of buf->pages") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Olga Kornievskaia <aglo@umich.edu> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-04-11NFS: Forbid setting AF_INET6 to "struct sockaddr_in"->sin_family.Tetsuo Handa1-1/+2
syzbot is reporting uninitialized value at rpc_sockaddr2uaddr() [1]. This is because syzbot is setting AF_INET6 to "struct sockaddr_in"->sin_family (which is embedded into user-visible "struct nfs_mount_data" structure) despite nfs23_validate_mount_data() cannot pass sizeof(struct sockaddr_in6) bytes of AF_INET6 address to rpc_sockaddr2uaddr(). Since "struct nfs_mount_data" structure is user-visible, we can't change "struct nfs_mount_data" to use "struct sockaddr_storage". Therefore, assuming that everybody is using AF_INET family when passing address via "struct nfs_mount_data"->addr, reject if its sin_family is not AF_INET. [1] https://syzkaller.appspot.com/bug?id=599993614e7cbbf66bc2656a919ab2a95fb5d75c Reported-by: syzbot <syzbot+047a11c361b872896a4f@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-04-09Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-2/+2
Pull misc fixes from Al Viro: "A few regression fixes from this cycle" * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: aio: use kmem_cache_free() instead of kfree() iov_iter: Fix build error without CONFIG_CRYPTO aio: Fix an error code in __io_submit_one()
2019-04-08io_uring: restrict IORING_SETUP_SQPOLL to rootJens Axboe1-0/+4
This options spawns a kernel side thread that will poll for submissions (and completions, if IORING_SETUP_IOPOLL is set). As this allows a user to potentially use more cycles outside of the normal hierarchy, restrict the use of this feature to root. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-08nfsd: Don't release the callback slot unless it was actually heldTrond Myklebust2-1/+8
If there are multiple callbacks queued, waiting for the callback slot when the callback gets shut down, then they all currently end up acting as if they hold the slot, and call nfsd4_cb_sequence_done() resulting in interesting side-effects. In addition, the 'retry_nowait' path in nfsd4_cb_sequence_done() causes a loop back to nfsd4_cb_prepare() without first freeing the slot, which causes a deadlock when nfsd41_cb_get_slot() gets called a second time. This patch therefore adds a boolean to track whether or not the callback did pick up the slot, so that it can do the right thing in these 2 cases. Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-04-07Merge tag 'for-linus-20190407' of git://git.kernel.dk/linux-blockLinus Torvalds1-0/+1
Pull block fixes from Jens Axboe: - Fixups for the pf/pcd queue handling (YueHaibing) - Revert of the three direct issue changes as they have been proven to cause an issue with dm-mpath (Bart) - Plug rq_count reset fix (Dongli) - io_uring double free in fileset registration error handling (me) - Make null_blk handle bad numa node passed in (John) - BFQ ifdef fix (Konstantin) - Flush queue leak fix (Shenghui) - Plug trace fix (Yufen) * tag 'for-linus-20190407' of git://git.kernel.dk/linux-block: xsysace: Fix error handling in ace_setup null_blk: prevent crash from bad home_node value block: Revert v5.0 blk_mq_request_issue_directly() changes paride/pcd: Fix potential NULL pointer dereference and mem leak blk-mq: do not reset plug->rq_count before the list is sorted paride/pf: Fix potential NULL pointer dereference io_uring: fix double free in case of fileset regitration failure blk-mq: add trace block plug and unplug for multiple queues block: use blk_free_flush_queue() to free hctx->fq in blk_mq_init_hctx block/bfq: fix ifdef for CONFIG_BFQ_GROUP_IOSCHED=y
2019-04-06fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlockKirill Smelkov2-2/+21
Commit 9c225f2655e3 ("vfs: atomic f_pos accesses as per POSIX") added locking for file.f_pos access and in particular made concurrent read and write not possible - now both those functions take f_pos lock for the whole run, and so if e.g. a read is blocked waiting for data, write will deadlock waiting for that read to complete. This caused regression for stream-like files where previously read and write could run simultaneously, but after that patch could not do so anymore. See e.g. commit 581d21a2d02a ("xenbus: fix deadlock on writes to /proc/xen/xenbus") which fixes such regression for particular case of /proc/xen/xenbus. The patch that added f_pos lock in 2014 did so to guarantee POSIX thread safety for read/write/lseek and added the locking to file descriptors of all regular files. In 2014 that thread-safety problem was not new as it was already discussed earlier in 2006. However even though 2006'th version of Linus's patch was adding f_pos locking "only for files that are marked seekable with FMODE_LSEEK (thus avoiding the stream-like objects like pipes and sockets)", the 2014 version - the one that actually made it into the tree as 9c225f2655e3 - is doing so irregardless of whether a file is seekable or not. See https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/ https://lwn.net/Articles/180387 https://lwn.net/Articles/180396 for historic context. The reason that it did so is, probably, that there are many files that are marked non-seekable, but e.g. their read implementation actually depends on knowing current position to correctly handle the read. Some examples: kernel/power/user.c snapshot_read fs/debugfs/file.c u32_array_read fs/fuse/control.c fuse_conn_waiting_read + ... drivers/hwmon/asus_atk0110.c atk_debugfs_ggrp_read arch/s390/hypfs/inode.c hypfs_read_iter ... Despite that, many nonseekable_open users implement read and write with pure stream semantics - they don't depend on passed ppos at all. And for those cases where read could wait for something inside, it creates a situation similar to xenbus - the write could be never made to go until read is done, and read is waiting for some, potentially external, event, for potentially unbounded time -> deadlock. Besides xenbus, there are 14 such places in the kernel that I've found with semantic patch (see below): drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write() drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write() drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write() drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write() net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write() drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write() drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write() drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write() net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write() drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write() drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write() drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write() drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write() drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write() In addition to the cases above another regression caused by f_pos locking is that now FUSE filesystems that implement open with FOPEN_NONSEEKABLE flag, can no longer implement bidirectional stream-like files - for the same reason as above e.g. read can deadlock write locking on file.f_pos in the kernel. FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990f715 ("fuse: implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and write routines not depending on current position at all, and with both read and write being potentially blocking operations: See https://github.com/libfuse/osspd https://lwn.net/Articles/308445 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1479-L1510 Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as "somewhat pipe-like files ..." with read handler not using offset. However that test implements only read without write and cannot exercise the deadlock scenario: https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131 https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163 https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216 I've actually hit the read vs write deadlock for real while implementing my FUSE filesystem where there is /head/watch file, for which open creates separate bidirectional socket-like stream in between filesystem and its user with both read and write being later performed simultaneously. And there it is semantically not easy to split the stream into two separate read-only and write-only channels: https://lab.nexedi.com/kirr/wendelin.core/blob/f13aa600/wcfs/wcfs.go#L88-169 Let's fix this regression. The plan is: 1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS - doing so would break many in-kernel nonseekable_open users which actually use ppos in read/write handlers. 2. Add stream_open() to kernel to open stream-like non-seekable file descriptors. Read and write on such file descriptors would never use nor change ppos. And with that property on stream-like files read and write will be running without taking f_pos lock - i.e. read and write could be running simultaneously. 3. With semantic patch search and convert to stream_open all in-kernel nonseekable_open users for which read and write actually do not depend on ppos and where there is no other methods in file_operations which assume @offset access. 4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via steam_open if that bit is present in filesystem open reply. It was tempting to change fs/fuse/ open handler to use stream_open instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE, and in particular GVFS which actually uses offset in its read and write handlers https://codesearch.debian.net/search?q=-%3Enonseekable+%3D https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481 so if we would do such a change it will break a real user. 5. Add stream_open and FOPEN_STREAM handling to stable kernels starting from v3.14+ (the kernel where 9c225f2655 first appeared). This will allow to patch OSSPD and other FUSE filesystems that provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE in their open handler and this way avoid the deadlock on all kernel versions. This should work because fs/fuse/ ignores unknown open flags returned from a filesystem and so passing FOPEN_STREAM to a kernel that is not aware of this flag cannot hurt. In turn the kernel that is not aware of FOPEN_STREAM will be < v3.14 where just FOPEN_NONSEEKABLE is sufficient to implement streams without read vs write deadlock. This patch adds stream_open, converts /proc/xen/xenbus to it and adds semantic patch to automatically locate in-kernel places that are either required to be converted due to read vs write deadlock, or that are just safe to be converted because read and write do not use ppos and there are no other funky methods in file_operations. Regarding semantic patch I've verified each generated change manually - that it is correct to convert - and each other nonseekable_open instance left - that it is either not correct to convert there, or that it is not converted due to current stream_open.cocci limitations. The script also does not convert files that should be valid to convert, but that currently have .llseek = noop_llseek or generic_file_llseek for unknown reason despite file being opened with nonseekable_open (e.g. drivers/input/mousedev.c) Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yongzhi Pan <panyongzhi@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Tejun Heo <tj@kernel.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Nikolaus Rath <Nikolaus@rath.org> Cc: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Kirill Smelkov <kirr@nexedi.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-05Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-6/+14
Merge misc fixes from Andrew Morton: "14 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: kernel/sysctl.c: fix out-of-bounds access when setting file-max mm/util.c: fix strndup_user() comment sh: fix multiple function definition build errors MAINTAINERS: add maintainer and replacing reviewer ARM/NUVOTON NPCM MAINTAINERS: fix bad pattern in ARM/NUVOTON NPCM mm: writeback: use exact memcg dirty counts psi: clarify the units used in pressure files mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd() hugetlbfs: fix memory leak for resv_map mm: fix vm_fault_t cast in VM_FAULT_GET_HINDEX() lib/lzo: fix bugs for very short or empty input include/linux/bitrev.h: fix constant bitrev kmemleak: powerpc: skip scanning holes in the .bss section lib/string.c: implement a basic bcmp
2019-04-05hugetlbfs: fix memory leak for resv_mapMike Kravetz1-6/+14
When mknod is used to create a block special file in hugetlbfs, it will allocate an inode and kmalloc a 'struct resv_map' via resv_map_alloc(). inode->i_mapping->private_data will point the newly allocated resv_map. However, when the device special file is opened bd_acquire() will set inode->i_mapping to bd_inode->i_mapping. Thus the pointer to the allocated resv_map is lost and the structure is leaked. Programs to reproduce: mount -t hugetlbfs nodev hugetlbfs mknod hugetlbfs/dev b 0 0 exec 30<> hugetlbfs/dev umount hugetlbfs/ resv_map structures are only needed for inodes which can have associated page allocations. To fix the leak, only allocate resv_map for those inodes which could possibly be associated with page allocations. Link: http://lkml.kernel.org/r/20190401213101.16476-1-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reported-by: Yufen Yu <yuyufen@huawei.com> Suggested-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-05nfsd/nfsd3_proc_readdir: fix buffer count and page pointersMurphy Zhou2-4/+24
After this commit f875a79 nfsd: allow nfsv3 readdir request to be larger. nfsv3 readdir request size can be larger than PAGE_SIZE. So if the directory been read is large enough, we can use multiple pages in rq_respages. Update buffer count and page pointers like we do in readdirplus to make this happen. Now listing a directory within 3000 files will panic because we are counting in a wrong way and would write on random page. Fixes: f875a79 "nfsd: allow nfsv3 readdir request to be larger" Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-04-05Merge tag 'trace-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-traceLinus Torvalds1-8/+9
Pull syscall-get-arguments cleanup and fixes from Steven Rostedt: "Andy Lutomirski approached me to tell me that the syscall_get_arguments() implementation in x86 was horrible and gcc certainly gets it wrong. He said that since the tracepoints only pass in 0 and 6 for i and n repectively, it should be optimized for that case. Inspecting the kernel, I discovered that all users pass in 0 for i and only one file passing in something other than 6 for the number of arguments. That code happens to be my own code used for the special syscall tracing. That can easily be converted to just using 0 and 6 as well, and only copying what is needed. Which is probably the faster path anyway for that case. Along the way, a couple of real fixes came from this as the syscall_get_arguments() function was incorrect for csky and riscv. x86 has been optimized to for the new interface that removes the variable number of arguments, but the other architectures could still use some loving and take more advantage of the simpler interface" * tag 'trace-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: syscalls: Remove start and number from syscall_set_arguments() args syscalls: Remove start and number from syscall_get_arguments() args csky: Fix syscall_get_arguments() and syscall_set_arguments() riscv: Fix syscall_get_arguments() and syscall_set_arguments() tracing/syscalls: Pass in hardcoded 6 into syscall_get_arguments() ptrace: Remove maxargs from task_current_syscall()
2019-04-04aio: use kmem_cache_free() instead of kfree()Wei Yongjun1-1/+1
memory allocated by kmem_cache_alloc() should be freed using kmem_cache_free(), not kfree(). Fixes: fa0ca2aee3be ("deal with get_reqs_available() in aio_get_req() itself") Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>