linux.git/kernel, branch v5.9-rc2

Merge tag 'core-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-08-23T18:05:47+00:00

Pull entry fix from Thomas Gleixner:
 "A single bug fix for the common entry code.

  The transcription of the x86 version messed up the reload of the
  syscall number from pt_regs after ptrace and seccomp which breaks
  syscall number rewriting"

* tag 'core-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  core/entry: Respect syscall number rewrites

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-08-23T17:52:33+00:00

Pull networking fixes from David Miller:
 "Nothing earth shattering here, lots of small fixes (f.e. missing RCU
  protection, bad ref counting, missing memset(), etc.) all over the
  place:

   1) Use get_file_rcu() in task_file iterator, from Yonghong Song.

   2) There are two ways to set remote source MAC addresses in macvlan
      driver, but only one of which validates things properly. Fix this.
      From Alvin Šipraga.

   3) Missing of_node_put() in gianfar probing, from Sumera
      Priyadarsini.

   4) Preserve device wanted feature bits across multiple netlink
      ethtool requests, from Maxim Mikityanskiy.

   5) Fix rcu_sched stall in task and task_file bpf iterators, from
      Yonghong Song.

   6) Avoid reset after device destroy in ena driver, from Shay
      Agroskin.

   7) Missing memset() in netlink policy export reallocation path, from
      Johannes Berg.

   8) Fix info leak in __smc_diag_dump(), from Peilin Ye.

   9) Decapsulate ECN properly for ipv6 in ipv4 tunnels, from Mark
      Tomlinson.

  10) Fix number of data stream negotiation in SCTP, from David Laight.

  11) Fix double free in connection tracker action module, from Alaa
      Hleihel.

  12) Don't allow empty NHA_GROUP attributes, from Nikolay Aleksandrov"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (46 commits)
  net: nexthop: don't allow empty NHA_GROUP
  bpf: Fix two typos in uapi/linux/bpf.h
  net: dsa: b53: check for timeout
  tipc: call rcu_read_lock() in tipc_aead_encrypt_done()
  net/sched: act_ct: Fix skb double-free in tcf_ct_handle_fragments() error flow
  net: sctp: Fix negotiation of the number of data streams.
  dt-bindings: net: renesas, ether: Improve schema validation
  gre6: Fix reception with IP6_TNL_F_RCV_DSCP_COPY
  hv_netvsc: Fix the queue_mapping in netvsc_vf_xmit()
  hv_netvsc: Remove "unlikely" from netvsc_select_queue
  bpf: selftests: global_funcs: Check err_str before strstr
  bpf: xdp: Fix XDP mode when no mode flags specified
  selftests/bpf: Remove test_align leftovers
  tools/resolve_btfids: Fix sections with wrong alignment
  net/smc: Prevent kernel-infoleak in __smc_diag_dump()
  sfc: fix build warnings on 32-bit
  net: phy: mscc: Fix a couple of spelling mistakes "spcified" -> "specified"
  libbpf: Fix map index used in error message
  net: gemini: Fix missing free_netdev() in error path of gemini_ethernet_port_probe()
  net: atlantic: Use readx_poll_timeout() for large timeout
  ...

Merge branch 'akpm' (patches from Andrew)

2020-08-21T21:44:48+00:00

Merge misc fixes from Andrew Morton:
 "11 patches.

  Subsystems affected by this: misc, mm/hugetlb, mm/vmalloc, mm/misc,
  romfs, relay, uprobes, squashfs, mm/cma, mm/pagealloc"

* emailed patches from Andrew Morton :
  mm, page_alloc: fix core hung in free_pcppages_bulk()
  mm: include CMA pages in lowmem_reserve at boot
  squashfs: avoid bio_alloc() failure with 1Mbyte blocks
  uprobes: __replace_page() avoid BUG in munlock_vma_page()
  kernel/relay.c: fix memleak on destroy relay channel
  romfs: fix uninitialized memory leak in romfs_dev_read()
  mm/rodata_test.c: fix missing function declaration
  mm/vunmap: add cond_resched() in vunmap_pmd_range
  khugepaged: adjust VM_BUG_ON_MM() in __khugepaged_enter()
  hugetlb_cgroup: convert comma to semicolon
  mailmap: add Andi Kleen

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

2020-08-21T19:54:50+00:00

Alexei Starovoitov says:

====================
pull-request: bpf 2020-08-21

The following pull-request contains BPF updates for your *net* tree.

We've added 11 non-merge commits during the last 5 day(s) which contain
a total of 12 files changed, 78 insertions(+), 24 deletions(-).

The main changes are:

1) three fixes in BPF task iterator logic, from Yonghong.

2) fix for compressed dwarf sections in vmlinux, from Jiri.

3) fix xdp attach regression, from Andrii.
====================

Signed-off-by: David S. Miller

uprobes: __replace_page() avoid BUG in munlock_vma_page()

2020-08-21T16:52:53+00:00

syzbot crashed on the VM_BUG_ON_PAGE(PageTail) in munlock_vma_page(), when
called from uprobes __replace_page().  Which of many ways to fix it?
Settled on not calling when PageCompound (since Head and Tail are equals
in this context, PageCompound the usual check in uprobes.c, and the prior
use of FOLL_SPLIT_PMD will have cleared PageMlocked already).

Fixes: 5a52c9df62b4 ("uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT")
Reported-by: syzbot 
Signed-off-by: Hugh Dickins 
Signed-off-by: Andrew Morton 
Reviewed-by: Srikar Dronamraju 
Acked-by: Song Liu 
Acked-by: Oleg Nesterov 
Cc: "Kirill A. Shutemov" 
Cc: 	[5.4+]
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2008161338360.20413@eggly.anvils
Signed-off-by: Linus Torvalds

kernel/relay.c: fix memleak on destroy relay channel

2020-08-21T16:52:53+00:00

kmemleak report memory leak as follows:

  unreferenced object 0x607ee4e5f948 (size 8):
  comm "syz-executor.1", pid 2098, jiffies 4295031601 (age 288.468s)
  hex dump (first 8 bytes):
  00 00 00 00 00 00 00 00 ........
  backtrace:
     relay_open kernel/relay.c:583 [inline]
     relay_open+0xb6/0x970 kernel/relay.c:563
     do_blk_trace_setup+0x4a8/0xb20 kernel/trace/blktrace.c:557
     __blk_trace_setup+0xb6/0x150 kernel/trace/blktrace.c:597
     blk_trace_ioctl+0x146/0x280 kernel/trace/blktrace.c:738
     blkdev_ioctl+0xb2/0x6a0 block/ioctl.c:613
     block_ioctl+0xe5/0x120 fs/block_dev.c:1871
     vfs_ioctl fs/ioctl.c:48 [inline]
     __do_sys_ioctl fs/ioctl.c:753 [inline]
     __se_sys_ioctl fs/ioctl.c:739 [inline]
     __x64_sys_ioctl+0x170/0x1ce fs/ioctl.c:739
     do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
     entry_SYSCALL_64_after_hwframe+0x44/0xa9

'chan->buf' is malloced in relay_open() by alloc_percpu() but not free
while destroy the relay channel.  Fix it by adding free_percpu() before
return from relay_destroy_channel().

Fixes: 017c59c042d0 ("relay: Use per CPU constructs for the relay channel buffer pointers")
Reported-by: Hulk Robot 
Signed-off-by: Wei Yongjun 
Signed-off-by: Andrew Morton 
Reviewed-by: Chris Wilson 
Cc: Al Viro 
Cc: Michael Ellerman 
Cc: David Rientjes 
Cc: Michel Lespinasse 
Cc: Daniel Axtens 
Cc: Thomas Gleixner 
Cc: Akash Goel 
Cc: 
Link: http://lkml.kernel.org/r/20200817122826.48518-1-weiyongjun1@huawei.com
Signed-off-by: Linus Torvalds

core/entry: Respect syscall number rewrites

2020-08-21T14:17:29+00:00

The transcript of the x86 entry code to the generic version failed to
reload the syscall number from ptregs after ptrace and seccomp have run,
which both can modify the syscall number in ptregs. It returns the original
syscall number instead which is obviously not the right thing to do.

Reload the syscall number to fix that.

Fixes: 142781e108b1 ("entry: Provide generic syscall entry functionality")
Reported-by: Kyle Huey  
Signed-off-by: Thomas Gleixner 
Tested-by: Kyle Huey  
Tested-by: Kees Cook 
Acked-by: Kees Cook 
Link: https://lore.kernel.org/r/87blj6ifo8.fsf@nanos.tec.linutronix.de

Merge tag 'dma-mapping-5.9-1' of git://git.infradead.org/users/hch/dma-mapping

2020-08-20T17:48:17+00:00

Pull dma-mapping fixes from Christoph Hellwig:
 "Fix more fallout from the dma-pool changes (Nicolas Saenz Julienne,
  me)"

* tag 'dma-mapping-5.9-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-pool: Only allocate from CMA when in same memory zone
  dma-pool: fix coherent pool allocations for IOMMU mappings

bpf: Avoid visit same object multiple times

2020-08-19T00:36:23+00:00

Currently when traversing all tasks, the next tid
is always increased by one. This may result in
visiting the same task multiple times in a
pid namespace.

This patch fixed the issue by seting the next
tid as pid_nr_ns(pid, ns) + 1, similar to
funciton next_tgid().

Signed-off-by: Yonghong Song 
Signed-off-by: Alexei Starovoitov 
Cc: Rik van Riel 
Link: https://lore.kernel.org/bpf/20200818222310.2181500-1-yhs@fb.com

bpf: Fix a rcu_sched stall issue with bpf task/task_file iterator

2020-08-19T00:36:23+00:00

In our production system, we observed rcu stalls when
'bpftool prog` is running.
  rcu: INFO: rcu_sched self-detected stall on CPU
  rcu: \x097-....: (20999 ticks this GP) idle=302/1/0x4000000000000000 softirq=1508852/1508852 fqs=4913
  \x09(t=21031 jiffies g=2534773 q=179750)
  NMI backtrace for cpu 7
  CPU: 7 PID: 184195 Comm: bpftool Kdump: loaded Tainted: G        W         5.8.0-00004-g68bfc7f8c1b4 #6
  Hardware name: Quanta Twin Lakes MP/Twin Lakes Passive MP, BIOS F09_3A17 05/03/2019
  Call Trace:
  
  dump_stack+0x57/0x70
  nmi_cpu_backtrace.cold+0x14/0x53
  ? lapic_can_unplug_cpu.cold+0x39/0x39
  nmi_trigger_cpumask_backtrace+0xb7/0xc7
  rcu_dump_cpu_stacks+0xa2/0xd0
  rcu_sched_clock_irq.cold+0x1ff/0x3d9
  ? tick_nohz_handler+0x100/0x100
  update_process_times+0x5b/0x90
  tick_sched_timer+0x5e/0xf0
  __hrtimer_run_queues+0x12a/0x2a0
  hrtimer_interrupt+0x10e/0x280
  __sysvec_apic_timer_interrupt+0x51/0xe0
  asm_call_on_stack+0xf/0x20
  
  sysvec_apic_timer_interrupt+0x6f/0x80
  asm_sysvec_apic_timer_interrupt+0x12/0x20
  RIP: 0010:task_file_seq_get_next+0x71/0x220
  Code: 00 00 8b 53 1c 49 8b 7d 00 89 d6 48 8b 47 20 44 8b 18 41 39 d3 76 75 48 8b 4f 20 8b 01 39 d0 76 61 41 89 d1 49 39 c1 48 19 c0 <48> 8b 49 08 21 d0 48 8d 04 c1 4c 8b 08 4d 85 c9 74 46 49 8b 41 38
  RSP: 0018:ffffc90006223e10 EFLAGS: 00000297
  RAX: ffffffffffffffff RBX: ffff888f0d172388 RCX: ffff888c8c07c1c0
  RDX: 00000000000f017b RSI: 00000000000f017b RDI: ffff888c254702c0
  RBP: ffffc90006223e68 R08: ffff888be2a1c140 R09: 00000000000f017b
  R10: 0000000000000002 R11: 0000000000100000 R12: ffff888f23c24118
  R13: ffffc90006223e60 R14: ffffffff828509a0 R15: 00000000ffffffff
  task_file_seq_next+0x52/0xa0
  bpf_seq_read+0xb9/0x320
  vfs_read+0x9d/0x180
  ksys_read+0x5f/0xe0
  do_syscall_64+0x38/0x60
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7f8815f4f76e
  Code: c0 e9 f6 fe ff ff 55 48 8d 3d 76 70 0a 00 48 89 e5 e8 36 06 02 00 66 0f 1f 44 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00 f0 ff ff 77 52 c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5
  RSP: 002b:00007fff8f9df578 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
  RAX: ffffffffffffffda RBX: 000000000170b9c0 RCX: 00007f8815f4f76e
  RDX: 0000000000001000 RSI: 00007fff8f9df5b0 RDI: 0000000000000007
  RBP: 00007fff8f9e05f0 R08: 0000000000000049 R09: 0000000000000010
  R10: 00007f881601fa40 R11: 0000000000000246 R12: 00007fff8f9e05a8
  R13: 00007fff8f9e05a8 R14: 0000000001917f90 R15: 000000000000e22e

Note that `bpftool prog` actually calls a task_file bpf iterator
program to establish an association between prog/map/link/btf anon
files and processes.

In the case where the above rcu stall occured, we had a process
having 1587 tasks and each task having roughly 81305 files.
This implied 129 million bpf prog invocations. Unfortunwtely none of
these files are prog/map/link/btf files so bpf iterator/prog needs
to traverse all these files and not able to return to user space
since there are no seq_file buffer overflow.

This patch fixed the issue in bpf_seq_read() to limit the number
of visited objects. If the maximum number of visited objects is
reached, no more objects will be visited in the current syscall.
If there is nothing written in the seq_file buffer, -EAGAIN will
return to the user so user can try again.

The maximum number of visited objects is set at 1 million.
In our Intel Xeon D-2191 2.3GHZ 18-core server, bpf_seq_read()
visiting 1 million files takes around 0.18 seconds.

We did not use cond_resched() since for some iterators, e.g.,
netlink iterator, where rcu read_lock critical section spans between
consecutive seq_ops->next(), which makes impossible to do cond_resched()
in the key while loop of function bpf_seq_read().

Signed-off-by: Yonghong Song 
Signed-off-by: Alexei Starovoitov 
Cc: Paul E. McKenney 
Link: https://lore.kernel.org/bpf/20200818222309.2181348-1-yhs@fb.com