13 Feb, 2018

1 commit

  • [ Upstream commit 4db428a7c9ab07e08783e0fcdc4ca0f555da0567 ]

    reuseport_add_sock() needs to deal with attaching a socket having
    its own sk_reuseport_cb, after a prior
    setsockopt(SO_ATTACH_REUSEPORT_?BPF)

    Without this fix, not only a WARN_ONCE() was issued, but we were also
    leaking memory.

    Thanks to sysbot and Eric Biggers for providing us nice C repros.

    ------------[ cut here ]------------
    socket already in reuseport group
    WARNING: CPU: 0 PID: 3496 at net/core/sock_reuseport.c:119  
    reuseport_add_sock+0x742/0x9b0 net/core/sock_reuseport.c:117
    Kernel panic - not syncing: panic_on_warn set ...

    CPU: 0 PID: 3496 Comm: syzkaller869503 Not tainted 4.15.0-rc6+ #245
    Hardware name: Google Google Compute Engine/Google Compute Engine,
    BIOS  
    Google 01/01/2011
    Call Trace:
      __dump_stack lib/dump_stack.c:17 [inline]
      dump_stack+0x194/0x257 lib/dump_stack.c:53
      panic+0x1e4/0x41c kernel/panic.c:183
      __warn+0x1dc/0x200 kernel/panic.c:547
      report_bug+0x211/0x2d0 lib/bug.c:184
      fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178
      fixup_bug arch/x86/kernel/traps.c:247 [inline]
      do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296
      do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
      invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:1079

    Fixes: ef456144da8e ("soreuseport: define reuseport groups")
    Signed-off-by: Eric Dumazet
    Reported-by: syzbot+c0ea2226f77a42936bf7@syzkaller.appspotmail.com
    Acked-by: Craig Gallek

    Signed-off-by: David S. Miller
    Signed-off-by: Greg Kroah-Hartman

    Eric Dumazet
     

02 Nov, 2017

1 commit

  • Many source files in the tree are missing licensing information, which
    makes it harder for compliance tools to determine the correct license.

    By default all files without license information are under the default
    license of the kernel, which is GPL version 2.

    Update the files which contain no license information with the 'GPL-2.0'
    SPDX license identifier. The SPDX identifier is a legally binding
    shorthand, which can be used instead of the full boiler plate text.

    This patch is based on work done by Thomas Gleixner and Kate Stewart and
    Philippe Ombredanne.

    How this work was done:

    Patches were generated and checked against linux-4.14-rc6 for a subset of
    the use cases:
    - file had no licensing information it it.
    - file was a */uapi/* one with no licensing information in it,
    - file was a */uapi/* one with existing licensing information,

    Further patches will be generated in subsequent months to fix up cases
    where non-standard license headers were used, and references to license
    had to be inferred by heuristics based on keywords.

    The analysis to determine which SPDX License Identifier to be applied to
    a file was done in a spreadsheet of side by side results from of the
    output of two independent scanners (ScanCode & Windriver) producing SPDX
    tag:value files created by Philippe Ombredanne. Philippe prepared the
    base worksheet, and did an initial spot review of a few 1000 files.

    The 4.13 kernel was the starting point of the analysis with 60,537 files
    assessed. Kate Stewart did a file by file comparison of the scanner
    results in the spreadsheet to determine which SPDX license identifier(s)
    to be applied to the file. She confirmed any determination that was not
    immediately clear with lawyers working with the Linux Foundation.

    Criteria used to select files for SPDX license identifier tagging was:
    - Files considered eligible had to be source code files.
    - Make and config files were included as candidates if they contained >5
    lines of source
    - File already had some variant of a license header in it (even if
    Reviewed-by: Philippe Ombredanne
    Reviewed-by: Thomas Gleixner
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

22 Oct, 2017

1 commit

  • Syzkaller stumbled upon a way to trigger
    WARNING: CPU: 1 PID: 13881 at net/core/sock_reuseport.c:41
    reuseport_alloc+0x306/0x3b0 net/core/sock_reuseport.c:39

    There are two initialization paths for the sock_reuseport structure in a
    socket: Through the udp/tcp bind paths of SO_REUSEPORT sockets or through
    SO_ATTACH_REUSEPORT_[CE]BPF before bind. The existing implementation
    assumedthat the socket lock protected both of these paths when it actually
    only protects the SO_ATTACH_REUSEPORT path. Syzkaller triggered this
    double allocation by running these paths concurrently.

    This patch moves the check for double allocation into the reuseport_alloc
    function which is protected by a global spin lock.

    Fixes: e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection")
    Fixes: c125e80b8868 ("soreuseport: fast reuseport TCP socket selection")
    Signed-off-by: Craig Gallek
    Signed-off-by: David S. Miller

    Craig Gallek
     

04 Apr, 2017

1 commit

  • Number of sockets is limited by 16-bit, so 64-bit allocation will never
    happen.

    16-bit ops are the worst code density-wise on x86_64 because of
    additional prefix (66).

    Space savings:

    add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-3 (-3)
    function old new delta
    reuseport_add_sock 539 536 -3

    Signed-off-by: Alexey Dobriyan
    Signed-off-by: David S. Miller

    Alexey Dobriyan
     

19 Oct, 2016

1 commit


20 Jan, 2016

1 commit

  • Marc Dionne discovered a NULL pointer dereference when setting
    SO_REUSEPORT on a socket after it is bound.
    This patch removes the assumption that at least one socket in the
    reuseport group is bound with the SO_REUSEPORT option before other
    bind calls occur.

    Fixes: e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection")
    Reported-by: Marc Dionne
    Signed-off-by: Craig Gallek
    Tested-by: Marc Dionne
    Signed-off-by: David S. Miller

    Craig Gallek
     

06 Jan, 2016

1 commit


05 Jan, 2016

2 commits

  • Expose socket options for setting a classic or extended BPF program
    for use when selecting sockets in an SO_REUSEPORT group. These options
    can be used on the first socket to belong to a group before bind or
    on any socket in the group after bind.

    This change includes refactoring of the existing sk_filter code to
    allow reuse of the existing BPF filter validation checks.

    Signed-off-by: Craig Gallek
    Acked-by: Alexei Starovoitov
    Signed-off-by: David S. Miller

    Craig Gallek
     
  • struct sock_reuseport is an optional shared structure referenced by each
    socket belonging to a reuseport group. When a socket is bound to an
    address/port not yet in use and the reuseport flag has been set, the
    structure will be allocated and attached to the newly bound socket.
    When subsequent calls to bind are made for the same address/port, the
    shared structure will be updated to include the new socket and the
    newly bound socket will reference the group structure.

    Usually, when an incoming packet was destined for a reuseport group,
    all sockets in the same group needed to be considered before a
    dispatching decision was made. With this structure, an appropriate
    socket can be found after looking up just one socket in the group.

    This shared structure will also allow for more complicated decisions to
    be made when selecting a socket (eg a BPF filter).

    This work is based off a similar implementation written by
    Ying Cai for implementing policy-based reuseport
    selection.

    Signed-off-by: Craig Gallek
    Acked-by: Eric Dumazet
    Signed-off-by: David S. Miller

    Craig Gallek