Revision da353fac65fede6b8b4cfe207f0d9408e3121105 authored by Daniel Jordan on 27 October 2021, 21:59:20 UTC, committed by David S. Miller on 28 October 2021, 13:41:20 UTC
sk->sk_err appears to expect a positive value, a convention that ktls
doesn't always follow and that leads to memory corruption in other code.
For instance,

    [kworker]
    tls_encrypt_done(..., err=<negative error from crypto request>)
      tls_err_abort(.., err)
        sk->sk_err = err;

    [task]
    splice_from_pipe_feed
      ...
        tls_sw_do_sendpage
          if (sk->sk_err) {
            ret = -sk->sk_err;  // ret is positive

    splice_from_pipe_feed (continued)
      ret = actor(...)  // ret is still positive and interpreted as bytes
                        // written, resulting in underflow of buf->len and
                        // sd->len, leading to huge buf->offset and bogus
                        // addresses computed in later calls to actor()

Fix all tls_err_abort() callers to pass a negative error code
consistently and centralize the error-prone sign flip there, throwing in
a warning to catch future misuse and uninlining the function so it
really does only warn once.

Cc: stable@vger.kernel.org
Fixes: c46234ebb4d1e ("tls: RX path for ktls")
Reported-by: syzbot+b187b77c8474f9648fae@syzkaller.appspotmail.com
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent a32f07d
Raw File
mkcompile_h
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0

TARGET=$1
ARCH=$2
SMP=$3
PREEMPT=$4
PREEMPT_RT=$5
CC_VERSION="$6"
LD=$7

# Do not expand names
set -f

# Fix the language to get consistent output
LC_ALL=C
export LC_ALL

if [ -z "$KBUILD_BUILD_VERSION" ]; then
	VERSION=$(cat .version 2>/dev/null || echo 1)
else
	VERSION=$KBUILD_BUILD_VERSION
fi

if [ -z "$KBUILD_BUILD_TIMESTAMP" ]; then
	TIMESTAMP=`date`
else
	TIMESTAMP=$KBUILD_BUILD_TIMESTAMP
fi
if test -z "$KBUILD_BUILD_USER"; then
	LINUX_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
else
	LINUX_COMPILE_BY=$KBUILD_BUILD_USER
fi
if test -z "$KBUILD_BUILD_HOST"; then
	LINUX_COMPILE_HOST=`uname -n`
else
	LINUX_COMPILE_HOST=$KBUILD_BUILD_HOST
fi

UTS_VERSION="#$VERSION"
CONFIG_FLAGS=""
if [ -n "$SMP" ] ; then CONFIG_FLAGS="SMP"; fi
if [ -n "$PREEMPT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"; fi
if [ -n "$PREEMPT_RT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT_RT"; fi

# Truncate to maximum length
UTS_LEN=64
UTS_VERSION="$(echo $UTS_VERSION $CONFIG_FLAGS $TIMESTAMP | cut -b -$UTS_LEN)"

# Generate a temporary compile.h

{ echo /\* This file is auto generated, version $VERSION \*/
  if [ -n "$CONFIG_FLAGS" ] ; then echo "/* $CONFIG_FLAGS */"; fi

  echo \#define UTS_MACHINE \"$ARCH\"

  echo \#define UTS_VERSION \"$UTS_VERSION\"

  printf '#define LINUX_COMPILE_BY "%s"\n' "$LINUX_COMPILE_BY"
  echo \#define LINUX_COMPILE_HOST \"$LINUX_COMPILE_HOST\"

  LD_VERSION=$($LD -v | head -n1 | sed 's/(compatible with [^)]*)//' \
		      | sed 's/[[:space:]]*$//')
  printf '#define LINUX_COMPILER "%s"\n' "$CC_VERSION, $LD_VERSION"
} > .tmpcompile

# Only replace the real compile.h if the new one is different,
# in order to preserve the timestamp and avoid unnecessary
# recompilations.
# We don't consider the file changed if only the date/time changed,
# unless KBUILD_BUILD_TIMESTAMP was explicitly set (e.g. for
# reproducible builds with that value referring to a commit timestamp).
# A kernel config change will increase the generation number, thus
# causing compile.h to be updated (including date/time) due to the
# changed comment in the
# first line.

if [ -z "$KBUILD_BUILD_TIMESTAMP" ]; then
   IGNORE_PATTERN="UTS_VERSION"
else
   IGNORE_PATTERN="NOT_A_PATTERN_TO_BE_MATCHED"
fi

if [ -r $TARGET ] && \
      grep -v $IGNORE_PATTERN $TARGET > .tmpver.1 && \
      grep -v $IGNORE_PATTERN .tmpcompile > .tmpver.2 && \
      cmp -s .tmpver.1 .tmpver.2; then
   rm -f .tmpcompile
else
   echo "  UPD     $TARGET"
   mv -f .tmpcompile $TARGET
fi
rm -f .tmpver.1 .tmpver.2
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