When handling shmem page fault the THP with corrupted subpage could be
PMD mapped if certain conditions are satisfied.  But kernel is supposed
to send SIGBUS when trying to map hwpoisoned page.

There are two paths which may do PMD map: fault around and regular
fault.

Before commit f9ce0be71d1f ("mm: Cleanup faultaround and finish_fault()
codepaths") the thing was even worse in fault around path.  The THP
could be PMD mapped as long as the VMA fits regardless what subpage is
accessed and corrupted.  After this commit as long as head page is not
corrupted the THP could be PMD mapped.

In the regular fault path the THP could be PMD mapped as long as the
corrupted page is not accessed and the VMA fits.

This loophole could be fixed by iterating every subpage to check if any
of them is hwpoisoned or not, but it is somewhat costly in page fault
path.

So introduce a new page flag called HasHWPoisoned on the first tail
page.  It indicates the THP has hwpoisoned subpage(s).  It is set if any
subpage of THP is found hwpoisoned by memory failure and after the
refcount is bumped successfully, then cleared when the THP is freed or
split.

The soft offline path doesn't need this since soft offline handler just
marks a subpage hwpoisoned when the subpage is migrated successfully.
But shmem THP didn't get split then migrated at all.

Link: https://lkml.kernel.org/r/20211020210755.23964-3-shy828301@gmail.com
Fixes: 800d8c63b2e9 ("shmem: add huge pages support")
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Daniel Borkmann says:

====================
pull-request: bpf 2021-10-26

We've added 12 non-merge commits during the last 7 day(s) which contain
a total of 23 files changed, 118 insertions(+), 98 deletions(-).

The main changes are:

1) Fix potential race window in BPF tail call compatibility check, from Toke Høiland-Jørgensen.

2) Fix memory leak in cgroup fs due to missing cgroup_bpf_offline(), from Quanyang Wang.

3) Fix file descriptor reference counting in generic_map_update_batch(), from Xu Kuohai.

4) Fix bpf_jit_limit knob to the max supported limit by the arch's JIT, from Lorenz Bauer.

5) Fix BPF sockmap ->poll callbacks for UDP and AF_UNIX sockets, from Cong Wang and Yucong Sun.

6) Fix BPF sockmap concurrency issue in TCP on non-blocking sendmsg calls, from Liu Jian.

7) Fix build failure of INODE_STORAGE and TASK_STORAGE maps on !CONFIG_NET, from Tejun Heo.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Fix potential race in tail call compatibility check
  bpf: Move BPF_MAP_TYPE for INODE_STORAGE and TASK_STORAGE outside of CONFIG_NET
  selftests/bpf: Use recv_timeout() instead of retries
  net: Implement ->sock_is_readable() for UDP and AF_UNIX
  skmsg: Extract and reuse sk_msg_is_readable()
  net: Rename ->stream_memory_read to ->sock_is_readable
  tcp_bpf: Fix one concurrency problem in the tcp_bpf_send_verdict function
  cgroup: Fix memory leak caused by missing cgroup_bpf_offline
  bpf: Fix error usage of map_fd and fdget() in generic_map_update_batch()
  bpf: Prevent increasing bpf_jit_limit above max
  bpf: Define bpf_jit_alloc_exec_limit for arm64 JIT
  bpf: Define bpf_jit_alloc_exec_limit for riscv JIT
====================

Link: https://lore.kernel.org/r/20211026201920.11296-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Lorenzo noticed that the code testing for program type compatibility of
tail call maps is potentially racy in that two threads could encounter a
map with an unset type simultaneously and both return true even though they
are inserting incompatible programs.

The race window is quite small, but artificially enlarging it by adding a
usleep_range() inside the check in bpf_prog_array_compatible() makes it
trivial to trigger from userspace with a program that does, essentially:

        map_fd = bpf_create_map(BPF_MAP_TYPE_PROG_ARRAY, 4, 4, 2, 0);
        pid = fork();
        if (pid) {
                key = 0;
                value = xdp_fd;
        } else {
                key = 1;
                value = tc_fd;
        }
        err = bpf_map_update_elem(map_fd, &key, &value, 0);

While the race window is small, it has potentially serious ramifications in
that triggering it would allow a BPF program to tail call to a program of a
different type. So let's get rid of it by protecting the update with a
spinlock. The commit in the Fixes tag is the last commit that touches the
code in question.

v2:
- Use a spinlock instead of an atomic variable and cmpxchg() (Alexei)
v3:
- Put lock and the members it protects into an embedded 'owner' struct (Daniel)

Fixes: 3324b584b6f6 ("ebpf: misc core cleanup")
Reported-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211026110019.363464-1-toke@redhat.com

bpf_types.h has BPF_MAP_TYPE_INODE_STORAGE and BPF_MAP_TYPE_TASK_STORAGE
declared inside #ifdef CONFIG_NET although they are built regardless of
CONFIG_NET. So, when CONFIG_BPF_SYSCALL && !CONFIG_NET, they are built
without the declarations leading to spurious build failures and not
registered to bpf_map_types making them unavailable.

Fix it by moving the BPF_MAP_TYPE for the two map types outside of
CONFIG_NET.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: a10787e6d58c ("bpf: Enable task local storage for tracing programs")
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/YXG1cuuSJDqHQfRY@slm.duckdns.org

tcp_bpf_sock_is_readable() is pretty much generic,
we can extract it and reuse it for non-TCP sockets.

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211008203306.37525-3-xiyou.wangcong@gmail.com

Restrict bpf_jit_limit to the maximum supported by the arch's JIT.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211014142554.53120-4-lmb@cloudflare.com

Pull ucounts fixes from Eric Biederman:
 "There has been one very hard to track down bug in the ucount code that
  we have been tracking since roughly v5.14 was released. Alex managed
  to find a reliable reproducer a few days ago and then I was able to
  instrument the code and figure out what the issue was.

  It turns out the sigqueue_alloc single atomic operation optimization
  did not play nicely with ucounts multiple level rlimits. It turned out
  that either sigqueue_alloc or sigqueue_free could be operating on
  multiple levels and trigger the conditions for the optimization on
  more than one level at the same time.

  To deal with that situation I have introduced inc_rlimit_get_ucounts
  and dec_rlimit_put_ucounts that just focuses on the optimization and
  the rlimit and ucount changes.

  While looking into the big bug I found I couple of other little issues
  so I am including those fixes here as well.

  When I have time I would very much like to dig into process ownership
  of the shared signal queue and see if we could pick a single owner for
  the entire queue so that all of the rlimits can count to that owner.
  That should entirely remove the need to call get_ucounts and
  put_ucounts in sigqueue_alloc and sigqueue_free. It is difficult
  because Linux unlike POSIX supports setuid that works on a single
  thread"

* 'ucount-fixes-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  ucounts: Move get_ucounts from cred_alloc_blank to key_change_session_keyring
  ucounts: Proper error handling in set_cred_ucounts
  ucounts: Pair inc_rlimit_ucounts with dec_rlimit_ucoutns in commit_creds
  ucounts: Fix signal ucount refcounting

Pull networking fixes from Jakub Kicinski:
 "Including fixes from netfilter, and can.

  We'll have one more fix for a socket accounting regression, it's still
  getting polished. Otherwise things look fine.

  Current release - regressions:

   - revert "vrf: reset skb conntrack connection on VRF rcv", there are
     valid uses for previous behavior

   - can: m_can: fix iomap_read_fifo() and iomap_write_fifo()

  Current release - new code bugs:

   - mlx5: e-switch, return correct error code on group creation failure

  Previous releases - regressions:

   - sctp: fix transport encap_port update in sctp_vtag_verify

   - stmmac: fix E2E delay mechanism (in PTP timestamping)

  Previous releases - always broken:

   - netfilter: ip6t_rt: fix out-of-bounds read of ipv6_rt_hdr

   - netfilter: xt_IDLETIMER: fix out-of-bound read caused by lack of
     init

   - netfilter: ipvs: make global sysctl read-only in non-init netns

   - tcp: md5: fix selection between vrf and non-vrf keys

   - ipv6: count rx stats on the orig netdev when forwarding

   - bridge: mcast: use multicast_membership_interval for IGMPv3

   - can:
      - j1939: fix UAF for rx_kref of j1939_priv abort sessions on
        receiving bad messages

      - isotp: fix TX buffer concurrent access in isotp_sendmsg() fix
        return error on FC timeout on TX path

   - ice: fix re-init of RDMA Tx queues and crash if RDMA was not inited

   - hns3: schedule the polling again when allocation fails, prevent
     stalls

   - drivers: add missing of_node_put() when aborting
     for_each_available_child_of_node()

   - ptp: fix possible memory leak and UAF in ptp_clock_register()

   - e1000e: fix packet loss in burst mode on Tiger Lake and later

   - mlx5e: ipsec: fix more checksum offload issues"

* tag 'net-5.15-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (75 commits)
  usbnet: sanity check for maxpacket
  net: enetc: make sure all traffic classes can send large frames
  net: enetc: fix ethtool counter name for PM0_TERR
  ptp: free 'vclock_index' in ptp_clock_release()
  sfc: Don't use netif_info before net_device setup
  sfc: Export fibre-specific supported link modes
  net/mlx5e: IPsec: Fix work queue entry ethernet segment checksum flags
  net/mlx5e: IPsec: Fix a misuse of the software parser's fields
  net/mlx5e: Fix vlan data lost during suspend flow
  net/mlx5: E-switch, Return correct error code on group creation failure
  net/mlx5: Lag, change multipath and bonding to be mutually exclusive
  ice: Add missing E810 device ids
  igc: Update I226_K device ID
  e1000e: Fix packet loss on Tiger Lake and later
  e1000e: Separate TGP board type from SPT
  ptp: Fix possible memory leak in ptp_clock_register()
  net: stmmac: Fix E2E delay mechanism
  nfc: st95hf: Make spi remove() callback return zero
  net: hns3: disable sriov before unload hclge layer
  net: hns3: fix vf reset workqueue cannot exit
  ...

Both multipath and bonding events are changing the HW LAG state
independently.
Handling one of the features events while the other is already
enabled can cause unwanted behavior, for example handling
bonding event while multipath enabled will disable the lag and
cause multipath to stop working.

Fix it by ignoring bonding event while in multipath and ignoring FIB
events while in bonding mode.

Fixes: 544fe7c2e654 ("net/mlx5e: Activate HW multipath and handle port affinity based on FIB events")
Signed-off-by: Maor Dickman <maord@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Pull tracing fix from Steven Rostedt:
 "Recursion fix for tracing.

  While cleaning up some of the tracing recursion protection logic, I
  discovered a scenario that the current design would miss, and would
  allow an infinite recursion. Removing an optimization trick that
  opened the hole fixes the issue and cleans up the code as well"

* tag 'trace-v5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Have all levels of checks prevent recursion