Skip to main content

Browse the archive

Revision 447ac906e189535e77dcb1f4bbe3f1bc917d4c12 authored by Patrick Steinhardt on 01 December 2022, 14:45:31 UTC, committed by Junio C Hamano on 05 December 2022, 06:14:16 UTC 
attr: fix out-of-bounds read with unreasonable amount of patterns
 
The `struct attr_stack` tracks the stack of all patterns together with
their attributes. When parsing a gitattributes file that has more than
2^31 such patterns though we may trigger multiple out-of-bounds reads on
64 bit platforms. This is because while the `num_matches` variable is an
unsigned integer, we always use a signed integer to iterate over them.

I have not been able to reproduce this issue due to memory constraints
on my systems. But despite the out-of-bounds reads, the worst thing that
can seemingly happen is to call free(3P) with a garbage pointer when
calling `attr_stack_free()`.

Fix this bug by using unsigned integers to iterate over the array. While
this makes the iteration somewhat awkward when iterating in reverse, it
is at least better than knowingly running into an out-of-bounds read.
While at it, convert the call to `ALLOC_GROW` to use `ALLOC_GROW_BY`
instead.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 34ace8b
Raw File
git-web--browse.sh 
#!/bin/sh
#
# This program launch a web browser on the html page
# describing a git command.
#
# Copyright (c) 2007 Christian Couder
# Copyright (c) 2006 Theodore Y. Ts'o
#
# This file is heavily stolen from git-mergetool.sh, by
# Theodore Y. Ts'o (thanks) that is:
#
# Copyright (c) 2006 Theodore Y. Ts'o
#
# This file is licensed under the GPL v2, or a later version
# at the discretion of Junio C Hamano or any other official
# git maintainer.
#

USAGE='[--browser=browser|--tool=browser] [--config=conf.var] url/file ...'

# This must be capable of running outside of git directory, so
# the vanilla git-sh-setup should not be used.
NONGIT_OK=Yes
. git-sh-setup

valid_custom_tool()
{
	browser_cmd="$(git config "browser.$1.cmd")"
	test -n "$browser_cmd"
}

valid_tool() {
	case "$1" in
	firefox | iceweasel | seamonkey | iceape | \
	chrome | google-chrome | chromium | chromium-browser | \
	konqueror | opera | w3m | elinks | links | lynx | dillo | open | \
	start | cygstart | xdg-open)
		;; # happy
	*)
		valid_custom_tool "$1" || return 1
		;;
	esac
}

init_browser_path() {
	browser_path=$(git config "browser.$1.path")
	if test -z "$browser_path" &&
	   test "$1" = chromium &&
	   type chromium-browser >/dev/null 2>&1
	then
		browser_path=chromium-browser
	fi
	: ${browser_path:="$1"}
}

while test $# != 0
do
	case "$1" in
	-b|--browser*|-t|--tool*)
		case "$#,$1" in
		*,*=*)
			browser=$(expr "z$1" : 'z-[^=]*=\(.*\)')
			;;
		1,*)
			usage ;;
		*)
			browser="$2"
			shift ;;
		esac
		;;
	-c|--config*)
		case "$#,$1" in
		*,*=*)
			conf=$(expr "z$1" : 'z-[^=]*=\(.*\)')
			;;
		1,*)
			usage ;;
		*)
			conf="$2"
			shift ;;
		esac
		;;
	--)
		break
		;;
	-*)
		usage
		;;
	*)
		break
		;;
	esac
	shift
done

test $# = 0 && usage

if test -z "$browser"
then
	for opt in "$conf" "web.browser"
	do
		test -z "$opt" && continue
		browser="$(git config $opt)"
		test -z "$browser" || break
	done
	if test -n "$browser" && ! valid_tool "$browser"; then
		echo >&2 "git config option $opt set to unknown browser: $browser"
		echo >&2 "Resetting to default..."
		unset browser
	fi
fi

if test -z "$browser" ; then
	if test -n "$DISPLAY"; then
		browser_candidates="firefox iceweasel google-chrome chrome chromium chromium-browser konqueror opera seamonkey iceape w3m elinks links lynx dillo xdg-open"
		if test "$KDE_FULL_SESSION" = "true"; then
			browser_candidates="konqueror $browser_candidates"
		fi
	else
		browser_candidates="w3m elinks links lynx"
	fi
	# SECURITYSESSIONID indicates an OS X GUI login session
	if test -n "$SECURITYSESSIONID" || test -n "$TERM_PROGRAM"
	then
		browser_candidates="open $browser_candidates"
	fi
	# /bin/start indicates MinGW
	if test -x /bin/start; then
		browser_candidates="start $browser_candidates"
	fi
	# /usr/bin/cygstart indicates Cygwin
	if test -x /usr/bin/cygstart; then
		browser_candidates="cygstart $browser_candidates"
	fi

	for i in $browser_candidates; do
		init_browser_path $i
		if type "$browser_path" > /dev/null 2>&1; then
			browser=$i
			break
		fi
	done
	test -z "$browser" && die "No known browser available."
else
	valid_tool "$browser" || die "Unknown browser '$browser'."

	init_browser_path "$browser"

	if test -z "$browser_cmd" && ! type "$browser_path" > /dev/null 2>&1; then
		die "The browser $browser is not available as '$browser_path'."
	fi
fi

case "$browser" in
firefox|iceweasel|seamonkey|iceape)
	# Check version because firefox < 2.0 does not support "-new-tab".
	vers=$(expr "$($browser_path -version)" : '.* \([0-9][0-9]*\)\..*')
	NEWTAB='-new-tab'
	test "$vers" -lt 2 && NEWTAB=''
	"$browser_path" $NEWTAB "$@" &
	;;
google-chrome|chrome|chromium|chromium-browser)
	# No need to specify newTab. It's default in chromium
	"$browser_path" "$@" &
	;;
konqueror)
	case "$(basename "$browser_path")" in
	konqueror)
		# It's simpler to use kfmclient to open a new tab in konqueror.
		browser_path="$(echo "$browser_path" | sed -e 's/konqueror$/kfmclient/')"
		type "$browser_path" > /dev/null 2>&1 || die "No '$browser_path' found."
		"$browser_path" newTab "$@" &
		;;
	kfmclient)
		"$browser_path" newTab "$@" &
		;;
	*)
		"$browser_path" "$@" &
		;;
	esac
	;;
w3m|elinks|links|lynx|open|cygstart|xdg-open)
	"$browser_path" "$@"
	;;
start)
	exec "$browser_path" '"web-browse"' "$@"
	;;
opera|dillo)
	"$browser_path" "$@" &
	;;
*)
	if test -n "$browser_cmd"; then
		( eval "$browser_cmd \"\$@\"" )
	fi
	;;
esac
back to top