[Qemu-commits] [qemu/qemu] b8c351: qemu-bridge-helper: Fix misuse of isspace()

[Peter Maydell]

  Branch: refs/heads/master
  Home:   https://github.com/qemu/qemu
  Commit: b8c3511d086c65fa4bc2ca7a128bb3a56ac95306
      
https://github.com/qemu/qemu/commit/b8c3511d086c65fa4bc2ca7a128bb3a56ac95306
  Author: Markus Armbruster <address@hidden>
  Date:   2019-05-22 (Wed, 22 May 2019)

  Changed paths:
    M qemu-bridge-helper.c

  Log Message:
  -----------
  qemu-bridge-helper: Fix misuse of isspace()

parse_acl_file() passes char values to isspace().  Undefined behavior
when the value is negative.  Not a security issue, because the
characters come from trusted $prefix/etc/qemu/bridge.conf and the
files it includes.

Furthermore, isspace()'s locale-dependence means qemu-bridge-helper
uses the user's locale for parsing $prefix/etc/bridge.conf.  Feels
wrong.

Use g_ascii_isspace() instead.  This fixes the undefined behavior, and
makes parsing of $prefix/etc/bridge.conf locale-independent.

Signed-off-by: Markus Armbruster <address@hidden>
Message-Id: <address@hidden>


  Commit: d18dc3af478664b1d5e0dd3ace1eabb9d160f244
      
https://github.com/qemu/qemu/commit/d18dc3af478664b1d5e0dd3ace1eabb9d160f244
  Author: Markus Armbruster <address@hidden>
  Date:   2019-05-22 (Wed, 22 May 2019)

  Changed paths:
    M tests/vhost-user-bridge.c

  Log Message:
  -----------
  tests/vhost-user-bridge: Fix misuse of isdigit()

vubr_set_host() passes char values to isdigit().  Undefined behavior
when the value is negative.

Fix by using qemu_isdigit() instead.

Signed-off-by: Markus Armbruster <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
Reviewed-by: Thomas Huth <address@hidden>
[Missing #include "qemu-common.h" fixed]


  Commit: 046aba169bc21c08823cfbe8d4f3b4ad116ac676
      
https://github.com/qemu/qemu/commit/046aba169bc21c08823cfbe8d4f3b4ad116ac676
  Author: Markus Armbruster <address@hidden>
  Date:   2019-05-22 (Wed, 22 May 2019)

  Changed paths:
    M gdbstub.c

  Log Message:
  -----------
  gdbstub: Reject invalid RLE repeat counts

"Debugging with GDB / Appendix E GDB Remote Serial Protocol /
Overview" specifies "The printable characters '#' and '$' or with a
numeric value greater than 126 must not be used."  gdb_read_byte()
only rejects values < 32.  This is wrong.  Impact depends on the caller:

* gdb_handlesig() passes a char.  Incorrectly accepts '#', '$' and
  '\127'.

* gdb_chr_receive() passes an uint8_t.  Additionally accepts
  characters with the most-significant bit set.

Correct the validity check to match the specification.

Signed-off-by: Markus Armbruster <address@hidden>
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
Message-Id: <address@hidden>


  Commit: 33c846efa22d62ea6489371789fc9fbd11b3cd3c
      
https://github.com/qemu/qemu/commit/33c846efa22d62ea6489371789fc9fbd11b3cd3c
  Author: Markus Armbruster <address@hidden>
  Date:   2019-05-22 (Wed, 22 May 2019)

  Changed paths:
    M gdbstub.c

  Log Message:
  -----------
  gdbstub: Fix misuse of isxdigit()

gdb_read_byte() passes its @ch argument to isxdigit().  Undefined
behavior when the value is negative.  Two callers:

* gdb_chr_receive() passes an uint8_t value.  Safe.

* gdb_handlesig() a char value.  Unsafe.  Not a security issue,
  because the characters come from the gdb client, which is trusted.

The obvious fix would be casting @ch to unsigned char.  But note that
gdb_read_byte() already casts @ch to uint8_t in many places.  Uses of
@ch without such a cast:

(1) Compare to a character constant with == or !=

(2) s->linesum += ch

(3) Store ch or ch ^ 0x20 into s->line_buf[]

(4) Check for invalid RLE count:
    ch < ' ' || ch == '#' || ch == '$' || ch > 126

(5) Pass to isxdigit()

(6) Pass to fromhex()

Change the parameter type from int to uint8_t, and drop the now
redundant casts.  Affects the above uses as follows:

(1) No change: the character constants are all non-negative.

(2) Effectively no change: we only ever use s->linesum & 0xff, and
    s->linesum is int.

(3) No change: s->line_buf[] is char[].

(4) No change.

(5) Avoid undefined behavior.

(6) No change: only reached when isxdigit(ch)

Signed-off-by: Markus Armbruster <address@hidden>
Message-Id: <address@hidden>


  Commit: db3d11ee3f0cb851124830172f0a93c3d77a450a
      
https://github.com/qemu/qemu/commit/db3d11ee3f0cb851124830172f0a93c3d77a450a
  Author: Markus Armbruster <address@hidden>
  Date:   2019-05-22 (Wed, 22 May 2019)

  Changed paths:
    M util/cutils.c

  Log Message:
  -----------
  cutils: Simplify how parse_uint() checks for whitespace

Use qemu_isspace() so we don't have to cast to unsigned char.

Signed-off-by: Markus Armbruster <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>


  Commit: 94b63b6007cb03dc77ab0833259c1e0d5e6b6fc1
      
https://github.com/qemu/qemu/commit/94b63b6007cb03dc77ab0833259c1e0d5e6b6fc1
  Author: Peter Maydell <address@hidden>
  Date:   2019-05-23 (Thu, 23 May 2019)

  Changed paths:
    M gdbstub.c
    M qemu-bridge-helper.c
    M tests/vhost-user-bridge.c
    M util/cutils.c

  Log Message:
  -----------
  Merge remote-tracking branch 'remotes/armbru/tags/pull-misc-2019-05-22' into 
staging

Miscellaneous patches for 2019-05-22

# gpg: Signature made Wed 22 May 2019 14:41:08 BST
# gpg:                using RSA key 3870B400EB918653
# gpg: Good signature from "Markus Armbruster <address@hidden>" [full]
# gpg:                 aka "Markus Armbruster <address@hidden>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-misc-2019-05-22:
  cutils: Simplify how parse_uint() checks for whitespace
  gdbstub: Fix misuse of isxdigit()
  gdbstub: Reject invalid RLE repeat counts
  tests/vhost-user-bridge: Fix misuse of isdigit()
  qemu-bridge-helper: Fix misuse of isspace()

Signed-off-by: Peter Maydell <address@hidden>


Compare: https://github.com/qemu/qemu/compare/297a082700d2...94b63b6007cb