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  1. Jan 26, 2019
  2. Jan 25, 2019
  3. Jan 24, 2019
  4. Jan 13, 2019
  5. Jan 12, 2019
    • Taehee Yoo's avatar
      net: bpfilter: disallow to remove bpfilter module while being used · 71a85084
      Taehee Yoo authored
      
      The bpfilter.ko module can be removed while functions of the bpfilter.ko
      are executing. so panic can occurred. in order to protect that, locks can
      be used. a bpfilter_lock protects routines in the
      __bpfilter_process_sockopt() but it's not enough because __exit routine
      can be executed concurrently.
      
      Now, the bpfilter_umh can not run in parallel.
      So, the module do not removed while it's being used and it do not
      double-create UMH process.
      The members of the umh_info and the bpfilter_umh_ops are protected by
      the bpfilter_umh_ops.lock.
      
      test commands:
         while :
         do
      	iptables -I FORWARD -m string --string ap --algo kmp &
      	modprobe -rv bpfilter &
         done
      
      splat looks like:
      [  298.623435] BUG: unable to handle kernel paging request at fffffbfff807440b
      [  298.628512] #PF error: [normal kernel read fault]
      [  298.633018] PGD 124327067 P4D 124327067 PUD 11c1a3067 PMD 119eb2067 PTE 0
      [  298.638859] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
      [  298.638859] CPU: 0 PID: 2997 Comm: iptables Not tainted 4.20.0+ #154
      [  298.638859] RIP: 0010:__mutex_lock+0x6b9/0x16a0
      [  298.638859] Code: c0 00 00 e8 89 82 ff ff 80 bd 8f fc ff ff 00 0f 85 d9 05 00 00 48 8b 85 80 fc ff ff 48 bf 00 00 00 00 00 fc ff df 48 c1 e8 03 <80> 3c 38 00 0f 85 1d 0e 00 00 48 8b 85 c8 fc ff ff 49 39 47 58 c6
      [  298.638859] RSP: 0018:ffff88810e7777a0 EFLAGS: 00010202
      [  298.638859] RAX: 1ffffffff807440b RBX: ffff888111bd4d80 RCX: 0000000000000000
      [  298.638859] RDX: 1ffff110235ff806 RSI: ffff888111bd5538 RDI: dffffc0000000000
      [  298.638859] RBP: ffff88810e777b30 R08: 0000000080000002 R09: 0000000000000000
      [  298.638859] R10: 0000000000000000 R11: 0000000000000000 R12: fffffbfff168a42c
      [  298.638859] R13: ffff888111bd4d80 R14: ffff8881040e9a05 R15: ffffffffc03a2000
      [  298.638859] FS:  00007f39e3758700(0000) GS:ffff88811ae00000(0000) knlGS:0000000000000000
      [  298.638859] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [  298.638859] CR2: fffffbfff807440b CR3: 000000011243e000 CR4: 00000000001006f0
      [  298.638859] Call Trace:
      [  298.638859]  ? mutex_lock_io_nested+0x1560/0x1560
      [  298.638859]  ? kasan_kmalloc+0xa0/0xd0
      [  298.638859]  ? kmem_cache_alloc+0x1c2/0x260
      [  298.638859]  ? __alloc_file+0x92/0x3c0
      [  298.638859]  ? alloc_empty_file+0x43/0x120
      [  298.638859]  ? alloc_file_pseudo+0x220/0x330
      [  298.638859]  ? sock_alloc_file+0x39/0x160
      [  298.638859]  ? __sys_socket+0x113/0x1d0
      [  298.638859]  ? __x64_sys_socket+0x6f/0xb0
      [  298.638859]  ? do_syscall_64+0x138/0x560
      [  298.638859]  ? entry_SYSCALL_64_after_hwframe+0x49/0xbe
      [  298.638859]  ? __alloc_file+0x92/0x3c0
      [  298.638859]  ? init_object+0x6b/0x80
      [  298.638859]  ? cyc2ns_read_end+0x10/0x10
      [  298.638859]  ? cyc2ns_read_end+0x10/0x10
      [  298.638859]  ? hlock_class+0x140/0x140
      [  298.638859]  ? sched_clock_local+0xd4/0x140
      [  298.638859]  ? sched_clock_local+0xd4/0x140
      [  298.638859]  ? check_flags.part.37+0x440/0x440
      [  298.638859]  ? __lock_acquire+0x4f90/0x4f90
      [  298.638859]  ? set_rq_offline.part.89+0x140/0x140
      [ ... ]
      
      Fixes: d2ba09c1 ("net: add skeleton of bpfilter kernel module")
      Signed-off-by: default avatarTaehee Yoo <ap420073@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      71a85084
    • Taehee Yoo's avatar
      net: bpfilter: restart bpfilter_umh when error occurred · 61fbf593
      Taehee Yoo authored
      
      The bpfilter_umh will be stopped via __stop_umh() when the bpfilter
      error occurred.
      The bpfilter_umh() couldn't start again because there is no restart
      routine.
      
      The section of the bpfilter_umh_{start/end} is no longer .init.rodata
      because these area should be reused in the restart routine. hence
      the section name is changed to .bpfilter_umh.
      
      The bpfilter_ops->start() is restart callback. it will be called when
      bpfilter_umh is stopped.
      The stop bit means bpfilter_umh is stopped. this bit is set by both
      start and stop routine.
      
      Before this patch,
      Test commands:
         $ iptables -vnL
         $ kill -9 <pid of bpfilter_umh>
         $ iptables -vnL
         [  480.045136] bpfilter: write fail -32
         $ iptables -vnL
      
      All iptables commands will fail.
      
      After this patch,
      Test commands:
         $ iptables -vnL
         $ kill -9 <pid of bpfilter_umh>
         $ iptables -vnL
         $ iptables -vnL
      
      Now, all iptables commands will work.
      
      Fixes: d2ba09c1 ("net: add skeleton of bpfilter kernel module")
      Signed-off-by: default avatarTaehee Yoo <ap420073@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      61fbf593
    • Taehee Yoo's avatar
      net: bpfilter: use cleanup callback to release umh_info · 5b4cb650
      Taehee Yoo authored
      
      Now, UMH process is killed, do_exit() calls the umh_info->cleanup callback
      to release members of the umh_info.
      This patch makes bpfilter_umh's cleanup routine to use the
      umh_info->cleanup callback.
      
      Signed-off-by: default avatarTaehee Yoo <ap420073@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      5b4cb650
    • Taehee Yoo's avatar
      umh: add exit routine for UMH process · 73ab1cb2
      Taehee Yoo authored
      
      A UMH process which is created by the fork_usermode_blob() such as
      bpfilter needs to release members of the umh_info when process is
      terminated.
      But the do_exit() does not release members of the umh_info. hence module
      which uses UMH needs own code to detect whether UMH process is
      terminated or not.
      But this implementation needs extra code for checking the status of
      UMH process. it eventually makes the code more complex.
      
      The new PF_UMH flag is added and it is used to identify UMH processes.
      The exit_umh() does not release members of the umh_info.
      Hence umh_info->cleanup callback should release both members of the
      umh_info and the private data.
      
      Suggested-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarTaehee Yoo <ap420073@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      73ab1cb2
  6. Jan 10, 2019
  7. Jan 09, 2019
    • WANG Chao's avatar
      x86, modpost: Replace last remnants of RETPOLINE with CONFIG_RETPOLINE · e4f35891
      WANG Chao authored
      
      Commit
      
        4cd24de3 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support")
      
      replaced the RETPOLINE define with CONFIG_RETPOLINE checks. Remove the
      remaining pieces.
      
       [ bp: Massage commit message. ]
      
      Fixes: 4cd24de3 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support")
      Signed-off-by: default avatarWANG Chao <chao.wang@ucloud.cn>
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Reviewed-by: default avatarZhenzhong Duan <zhenzhong.duan@oracle.com>
      Reviewed-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: David Woodhouse <dwmw@amazon.co.uk>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Jessica Yu <jeyu@kernel.org>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
      Cc: Michal Marek <michal.lkml@markovi.net>
      Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: linux-kbuild@vger.kernel.org
      Cc: srinivas.eeda@oracle.com
      Cc: stable <stable@vger.kernel.org>
      Cc: x86-ml <x86@kernel.org>
      Link: https://lkml.kernel.org/r/20181210163725.95977-1-chao.wang@ucloud.cn
      e4f35891
    • Borislav Petkov's avatar
      x86/cache: Rename config option to CONFIG_X86_RESCTRL · 90802938
      Borislav Petkov authored
      
      CONFIG_RESCTRL is too generic. The final goal is to have a generic
      option called like this which is selected by the arch-specific ones
      CONFIG_X86_RESCTRL and CONFIG_ARM64_RESCTRL. The generic one will
      cover the resctrl filesystem and other generic and shared bits of
      functionality.
      
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Suggested-by: default avatarIngo Molnar <mingo@kernel.org>
      Requested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Cc: Babu Moger <babu.moger@amd.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: James Morse <james.morse@arm.com>
      Cc: Reinette Chatre <reinette.chatre@intel.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: x86@kernel.org
      Link: http://lkml.kernel.org/r/20190108171401.GC12235@zn.tnic
      90802938
    • Mel Gorman's avatar
      mm, page_alloc: do not wake kswapd with zone lock held · 73444bc4
      Mel Gorman authored
      syzbot reported the following regression in the latest merge window and
      it was confirmed by Qian Cai that a similar bug was visible from a
      different context.
      
        ======================================================
        WARNING: possible circular locking dependency detected
        4.20.0+ #297 Not tainted
        ------------------------------------------------------
        syz-executor0/8529 is trying to acquire lock:
        000000005e7fb829 (&pgdat->kswapd_wait){....}, at:
        __wake_up_common_lock+0x19e/0x330 kernel/sched/wait.c:120
      
        but task is already holding lock:
        000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: spin_lock
        include/linux/spinlock.h:329 [inline]
        000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: rmqueue_bulk
        mm/page_alloc.c:2548 [inline]
        000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: __rmqueue_pcplist
        mm/page_alloc.c:3021 [inline]
        000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: rmqueue_pcplist
        mm/page_alloc.c:3050 [inline]
        000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: rmqueue
        mm/page_alloc.c:3072 [inline]
        000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at:
        get_page_from_freelist+0x1bae/0x52a0 mm/page_alloc.c:3491
      
      It appears to be a false positive in that the only way the lock ordering
      should be inverted is if kswapd is waking itself and the wakeup
      allocates debugging objects which should already be allocated if it's
      kswapd doing the waking.  Nevertheless, the possibility exists and so
      it's best to avoid the problem.
      
      This patch flags a zone as needing a kswapd using the, surprisingly,
      unused zone flag field.  The flag is read without the lock held to do
      the wakeup.  It's possible that the flag setting context is not the same
      as the flag clearing context or for small races to occur.  However, each
      race possibility is harmless and there is no visible degredation in
      fragmentation treatment.
      
      While zone->flag could have continued to be unused, there is potential
      for moving some existing fields into the flags field instead.
      Particularly read-mostly ones like zone->initialized and
      zone->contiguous.
      
      Link: http://lkml.kernel.org/r/20190103225712.GJ31517@techsingularity.net
      
      
      Fixes: 1c30844d ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
      Reported-by: default avatar <syzbot+93d94a001cfbce9e60e1@syzkaller.appspotmail.com>
      Signed-off-by: default avatarMel Gorman <mgorman@techsingularity.net>
      Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
      Tested-by: default avatarQian Cai <cai@lca.pw>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Michal Hocko <mhocko@suse.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      73444bc4
  8. Jan 08, 2019
  9. Jan 07, 2019
  10. Jan 06, 2019
    • Eric Biggers's avatar
      fscrypt: add Adiantum support · 8094c3ce
      Eric Biggers authored
      Add support for the Adiantum encryption mode to fscrypt.  Adiantum is a
      tweakable, length-preserving encryption mode with security provably
      reducible to that of XChaCha12 and AES-256, subject to a security bound.
      It's also a true wide-block mode, unlike XTS.  See the paper
      "Adiantum: length-preserving encryption for entry-level processors"
      (https://eprint.iacr.org/2018/720.pdf
      
      ) for more details.  Also see
      commit 059c2a4d ("crypto: adiantum - add Adiantum support").
      
      On sufficiently long messages, Adiantum's bottlenecks are XChaCha12 and
      the NH hash function.  These algorithms are fast even on processors
      without dedicated crypto instructions.  Adiantum makes it feasible to
      enable storage encryption on low-end mobile devices that lack AES
      instructions; currently such devices are unencrypted.  On ARM Cortex-A7,
      on 4096-byte messages Adiantum encryption is about 4 times faster than
      AES-256-XTS encryption; decryption is about 5 times faster.
      
      In fscrypt, Adiantum is suitable for encrypting both file contents and
      names.  With filenames, it fixes a known weakness: when two filenames in
      a directory share a common prefix of >= 16 bytes, with CTS-CBC their
      encrypted filenames share a common prefix too, leaking information.
      Adiantum does not have this problem.
      
      Since Adiantum also accepts long tweaks (IVs), it's also safe to use the
      master key directly for Adiantum encryption rather than deriving
      per-file keys, provided that the per-file nonce is included in the IVs
      and the master key isn't used for any other encryption mode.  This
      configuration saves memory and improves performance.  A new fscrypt
      policy flag is added to allow users to opt-in to this configuration.
      
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      8094c3ce
    • Daniel Borkmann's avatar
      bpf: fix sanitation of alu op with pointer / scalar type from different paths · d3bd7413
      Daniel Borkmann authored
      
      While 979d63d5 ("bpf: prevent out of bounds speculation on pointer
      arithmetic") took care of rejecting alu op on pointer when e.g. pointer
      came from two different map values with different map properties such as
      value size, Jann reported that a case was not covered yet when a given
      alu op is used in both "ptr_reg += reg" and "numeric_reg += reg" from
      different branches where we would incorrectly try to sanitize based
      on the pointer's limit. Catch this corner case and reject the program
      instead.
      
      Fixes: 979d63d5 ("bpf: prevent out of bounds speculation on pointer arithmetic")
      Reported-by: default avatarJann Horn <jannh@google.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      d3bd7413
    • Masahiro Yamada's avatar
      arch: remove stale comments "UAPI Header export list" · d4ce5458
      Masahiro Yamada authored
      
      These comments are leftovers of commit fcc8487d ("uapi: export all
      headers under uapi directories").
      
      Prior to that commit, exported headers must be explicitly added to
      header-y. Now, all headers under the uapi/ directories are exported.
      
      Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
      d4ce5458
    • Masahiro Yamada's avatar
      jump_label: move 'asm goto' support test to Kconfig · e9666d10
      Masahiro Yamada authored
      
      Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".
      
      The jump label is controlled by HAVE_JUMP_LABEL, which is defined
      like this:
      
        #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
        # define HAVE_JUMP_LABEL
        #endif
      
      We can improve this by testing 'asm goto' support in Kconfig, then
      make JUMP_LABEL depend on CC_HAS_ASM_GOTO.
      
      Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
      match to the real kernel capability.
      
      Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
      Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
      Tested-by: default avatarSedat Dilek <sedat.dilek@gmail.com>
      e9666d10
  11. Jan 04, 2019
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