Revision 633593a808980f82d251d0ca89730d8bb8b0220c authored by Eric Dumazet on 10 March 2022, 00:11:45 UTC, committed by Jakub Kicinski on 10 March 2022, 22:46:42 UTC
syzbot reported a kernel infoleak [1] of 4 bytes. After analysis, it turned out r->idiag_expires is not initialized if inet_sctp_diag_fill() calls inet_diag_msg_common_fill() Make sure to clear idiag_timer/idiag_retrans/idiag_expires and let inet_diag_msg_sctpasoc_fill() fill them again if needed. [1] BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline] BUG: KMSAN: kernel-infoleak in copyout lib/iov_iter.c:154 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x6ef/0x25a0 lib/iov_iter.c:668 instrument_copy_to_user include/linux/instrumented.h:121 [inline] copyout lib/iov_iter.c:154 [inline] _copy_to_iter+0x6ef/0x25a0 lib/iov_iter.c:668 copy_to_iter include/linux/uio.h:162 [inline] simple_copy_to_iter+0xf3/0x140 net/core/datagram.c:519 __skb_datagram_iter+0x2d5/0x11b0 net/core/datagram.c:425 skb_copy_datagram_iter+0xdc/0x270 net/core/datagram.c:533 skb_copy_datagram_msg include/linux/skbuff.h:3696 [inline] netlink_recvmsg+0x669/0x1c80 net/netlink/af_netlink.c:1977 sock_recvmsg_nosec net/socket.c:948 [inline] sock_recvmsg net/socket.c:966 [inline] __sys_recvfrom+0x795/0xa10 net/socket.c:2097 __do_sys_recvfrom net/socket.c:2115 [inline] __se_sys_recvfrom net/socket.c:2111 [inline] __x64_sys_recvfrom+0x19d/0x210 net/socket.c:2111 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was created at: slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3247 [inline] __kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4975 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0x545/0xf90 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1158 [inline] netlink_dump+0x3e5/0x16c0 net/netlink/af_netlink.c:2248 __netlink_dump_start+0xcf8/0xe90 net/netlink/af_netlink.c:2373 netlink_dump_start include/linux/netlink.h:254 [inline] inet_diag_handler_cmd+0x2e7/0x400 net/ipv4/inet_diag.c:1341 sock_diag_rcv_msg+0x24a/0x620 netlink_rcv_skb+0x40c/0x7e0 net/netlink/af_netlink.c:2494 sock_diag_rcv+0x63/0x80 net/core/sock_diag.c:277 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x1093/0x1360 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x14d9/0x1720 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] sock_write_iter+0x594/0x690 net/socket.c:1061 do_iter_readv_writev+0xa7f/0xc70 do_iter_write+0x52c/0x1500 fs/read_write.c:851 vfs_writev fs/read_write.c:924 [inline] do_writev+0x645/0xe00 fs/read_write.c:967 __do_sys_writev fs/read_write.c:1040 [inline] __se_sys_writev fs/read_write.c:1037 [inline] __x64_sys_writev+0xe5/0x120 fs/read_write.c:1037 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Bytes 68-71 of 2508 are uninitialized Memory access of size 2508 starts at ffff888114f9b000 Data copied to user address 00007f7fe09ff2e0 CPU: 1 PID: 3478 Comm: syz-executor306 Not tainted 5.17.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Link: https://lore.kernel.org/r/20220310001145.297371-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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config
#!/usr/bin/env bash
# SPDX-License-Identifier: GPL-2.0
# Manipulate options in a .config file from the command line
myname=${0##*/}
# If no prefix forced, use the default CONFIG_
CONFIG_="${CONFIG_-CONFIG_}"
# We use an uncommon delimiter for sed substitutions
SED_DELIM=$(echo -en "\001")
usage() {
cat >&2 <<EOL
Manipulate options in a .config file from the command line.
Usage:
$myname options command ...
commands:
--enable|-e option Enable option
--disable|-d option Disable option
--module|-m option Turn option into a module
--set-str option string
Set option to "string"
--set-val option value
Set option to value
--undefine|-u option Undefine option
--state|-s option Print state of option (n,y,m,undef)
--enable-after|-E beforeopt option
Enable option directly after other option
--disable-after|-D beforeopt option
Disable option directly after other option
--module-after|-M beforeopt option
Turn option into module directly after other option
commands can be repeated multiple times
options:
--file config-file .config file to change (default .config)
--keep-case|-k Keep next symbols' case (dont' upper-case it)
$myname doesn't check the validity of the .config file. This is done at next
make time.
By default, $myname will upper-case the given symbol. Use --keep-case to keep
the case of all following symbols unchanged.
$myname uses 'CONFIG_' as the default symbol prefix. Set the environment
variable CONFIG_ to the prefix to use. Eg.: CONFIG_="FOO_" $myname ...
EOL
exit 1
}
checkarg() {
ARG="$1"
if [ "$ARG" = "" ] ; then
usage
fi
case "$ARG" in
${CONFIG_}*)
ARG="${ARG/${CONFIG_}/}"
;;
esac
if [ "$MUNGE_CASE" = "yes" ] ; then
ARG="`echo $ARG | tr a-z A-Z`"
fi
}
txt_append() {
local anchor="$1"
local insert="$2"
local infile="$3"
local tmpfile="$infile.swp"
# sed append cmd: 'a\' + newline + text + newline
cmd="$(printf "a\\%b$insert" "\n")"
sed -e "/$anchor/$cmd" "$infile" >"$tmpfile"
# replace original file with the edited one
mv "$tmpfile" "$infile"
}
txt_subst() {
local before="$1"
local after="$2"
local infile="$3"
local tmpfile="$infile.swp"
sed -e "s$SED_DELIM$before$SED_DELIM$after$SED_DELIM" "$infile" >"$tmpfile"
# replace original file with the edited one
mv "$tmpfile" "$infile"
}
txt_delete() {
local text="$1"
local infile="$2"
local tmpfile="$infile.swp"
sed -e "/$text/d" "$infile" >"$tmpfile"
# replace original file with the edited one
mv "$tmpfile" "$infile"
}
set_var() {
local name=$1 new=$2 before=$3
name_re="^($name=|# $name is not set)"
before_re="^($before=|# $before is not set)"
if test -n "$before" && grep -Eq "$before_re" "$FN"; then
txt_append "^$before=" "$new" "$FN"
txt_append "^# $before is not set" "$new" "$FN"
elif grep -Eq "$name_re" "$FN"; then
txt_subst "^$name=.*" "$new" "$FN"
txt_subst "^# $name is not set" "$new" "$FN"
else
echo "$new" >>"$FN"
fi
}
undef_var() {
local name=$1
txt_delete "^$name=" "$FN"
txt_delete "^# $name is not set" "$FN"
}
if [ "$1" = "--file" ]; then
FN="$2"
if [ "$FN" = "" ] ; then
usage
fi
shift 2
else
FN=.config
fi
if [ "$1" = "" ] ; then
usage
fi
MUNGE_CASE=yes
while [ "$1" != "" ] ; do
CMD="$1"
shift
case "$CMD" in
--keep-case|-k)
MUNGE_CASE=no
continue
;;
--refresh)
;;
--*-after|-E|-D|-M)
checkarg "$1"
A=$ARG
checkarg "$2"
B=$ARG
shift 2
;;
-*)
checkarg "$1"
shift
;;
esac
case "$CMD" in
--enable|-e)
set_var "${CONFIG_}$ARG" "${CONFIG_}$ARG=y"
;;
--disable|-d)
set_var "${CONFIG_}$ARG" "# ${CONFIG_}$ARG is not set"
;;
--module|-m)
set_var "${CONFIG_}$ARG" "${CONFIG_}$ARG=m"
;;
--set-str)
# sed swallows one level of escaping, so we need double-escaping
set_var "${CONFIG_}$ARG" "${CONFIG_}$ARG=\"${1//\"/\\\\\"}\""
shift
;;
--set-val)
set_var "${CONFIG_}$ARG" "${CONFIG_}$ARG=$1"
shift
;;
--undefine|-u)
undef_var "${CONFIG_}$ARG"
;;
--state|-s)
if grep -q "# ${CONFIG_}$ARG is not set" $FN ; then
echo n
else
V="$(grep "^${CONFIG_}$ARG=" $FN)"
if [ $? != 0 ] ; then
echo undef
else
V="${V/#${CONFIG_}$ARG=/}"
V="${V/#\"/}"
V="${V/%\"/}"
V="${V//\\\"/\"}"
echo "${V}"
fi
fi
;;
--enable-after|-E)
set_var "${CONFIG_}$B" "${CONFIG_}$B=y" "${CONFIG_}$A"
;;
--disable-after|-D)
set_var "${CONFIG_}$B" "# ${CONFIG_}$B is not set" "${CONFIG_}$A"
;;
--module-after|-M)
set_var "${CONFIG_}$B" "${CONFIG_}$B=m" "${CONFIG_}$A"
;;
# undocumented because it ignores --file (fixme)
--refresh)
yes "" | make oldconfig
;;
*)
echo "bad command: $CMD" >&2
usage
;;
esac
done
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