Revision d21d40605bca7bd5fc23ef03d4c1ca1f48bc2cae authored by Kuniyuki Iwashima on 01 April 2024, 21:10:04 UTC, committed by Jakub Kicinski on 03 April 2024, 02:10:57 UTC
syzkaller reported infinite recursive calls of fib6_dump_done() during
netlink socket destruction. [1]
From the log, syzkaller sent an AF_UNSPEC RTM_GETROUTE message, and then
the response was generated. The following recvmmsg() resumed the dump
for IPv6, but the first call of inet6_dump_fib() failed at kzalloc() due
to the fault injection. [0]
12:01:34 executing program 3:
r0 = socket$nl_route(0x10, 0x3, 0x0)
sendmsg$nl_route(r0, ... snip ...)
recvmmsg(r0, ... snip ...) (fail_nth: 8)
Here, fib6_dump_done() was set to nlk_sk(sk)->cb.done, and the next call
of inet6_dump_fib() set it to nlk_sk(sk)->cb.args[3]. syzkaller stopped
receiving the response halfway through, and finally netlink_sock_destruct()
called nlk_sk(sk)->cb.done().
fib6_dump_done() calls fib6_dump_end() and nlk_sk(sk)->cb.done() if it
is still not NULL. fib6_dump_end() rewrites nlk_sk(sk)->cb.done() by
nlk_sk(sk)->cb.args[3], but it has the same function, not NULL, calling
itself recursively and hitting the stack guard page.
To avoid the issue, let's set the destructor after kzalloc().
[0]:
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 432110 Comm: syz-executor.3 Not tainted 6.8.0-12821-g537c2e91d354-dirty #11
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:117)
should_fail_ex (lib/fault-inject.c:52 lib/fault-inject.c:153)
should_failslab (mm/slub.c:3733)
kmalloc_trace (mm/slub.c:3748 mm/slub.c:3827 mm/slub.c:3992)
inet6_dump_fib (./include/linux/slab.h:628 ./include/linux/slab.h:749 net/ipv6/ip6_fib.c:662)
rtnl_dump_all (net/core/rtnetlink.c:4029)
netlink_dump (net/netlink/af_netlink.c:2269)
netlink_recvmsg (net/netlink/af_netlink.c:1988)
____sys_recvmsg (net/socket.c:1046 net/socket.c:2801)
___sys_recvmsg (net/socket.c:2846)
do_recvmmsg (net/socket.c:2943)
__x64_sys_recvmmsg (net/socket.c:3041 net/socket.c:3034 net/socket.c:3034)
[1]:
BUG: TASK stack guard page was hit at 00000000f2fa9af1 (stack is 00000000b7912430..000000009a436beb)
stack guard page: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 223719 Comm: kworker/1:3 Not tainted 6.8.0-12821-g537c2e91d354-dirty #11
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Workqueue: events netlink_sock_destruct_work
RIP: 0010:fib6_dump_done (net/ipv6/ip6_fib.c:570)
Code: 3c 24 e8 f3 e9 51 fd e9 28 fd ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 41 57 41 56 41 55 41 54 55 48 89 fd <53> 48 8d 5d 60 e8 b6 4d 07 fd 48 89 da 48 b8 00 00 00 00 00 fc ff
RSP: 0018:ffffc9000d980000 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffffffff84405990 RCX: ffffffff844059d3
RDX: ffff8881028e0000 RSI: ffffffff84405ac2 RDI: ffff88810c02f358
RBP: ffff88810c02f358 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000224 R12: 0000000000000000
R13: ffff888007c82c78 R14: ffff888007c82c68 R15: ffff888007c82c68
FS: 0000000000000000(0000) GS:ffff88811b100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc9000d97fff8 CR3: 0000000102309002 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
<#DF>
</#DF>
<TASK>
fib6_dump_done (net/ipv6/ip6_fib.c:572 (discriminator 1))
fib6_dump_done (net/ipv6/ip6_fib.c:572 (discriminator 1))
...
fib6_dump_done (net/ipv6/ip6_fib.c:572 (discriminator 1))
fib6_dump_done (net/ipv6/ip6_fib.c:572 (discriminator 1))
netlink_sock_destruct (net/netlink/af_netlink.c:401)
__sk_destruct (net/core/sock.c:2177 (discriminator 2))
sk_destruct (net/core/sock.c:2224)
__sk_free (net/core/sock.c:2235)
sk_free (net/core/sock.c:2246)
process_one_work (kernel/workqueue.c:3259)
worker_thread (kernel/workqueue.c:3329 kernel/workqueue.c:3416)
kthread (kernel/kthread.c:388)
ret_from_fork (arch/x86/kernel/process.c:153)
ret_from_fork_asm (arch/x86/entry/entry_64.S:256)
Modules linked in:
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240401211003.25274-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
1 parent 5d872c9
objdiff
#!/bin/bash
# SPDX-License-Identifier: GPL-2.0-only
# objdiff - a small script for validating that a commit or series of commits
# didn't change object code.
#
# Copyright 2014, Jason Cooper <jason@lakedaemon.net>
#
# usage example:
#
# $ git checkout COMMIT_A
# $ <your fancy build command here>
# $ ./scripts/objdiff record path/to/*.o
#
# $ git checkout COMMIT_B
# $ <your fancy build command here>
# $ ./scripts/objdiff record path/to/*.o
#
# $ ./scripts/objdiff diff COMMIT_A COMMIT_B
# $
# And to clean up (everything is in .objdiff/*)
# $ ./scripts/objdiff clean all
#
# Note: 'make mrproper' will also remove .objdiff
SRCTREE=$(cd $(git rev-parse --show-toplevel 2>/dev/null); pwd)
if [ -z "$SRCTREE" ]; then
echo >&2 "ERROR: Not a git repository."
exit 1
fi
TMPD=$SRCTREE/.objdiff
usage() {
echo >&2 "Usage: $0 <command> <args>"
echo >&2 " record <list of object files or directories>"
echo >&2 " diff <commitA> <commitB>"
echo >&2 " clean all | <commit>"
exit 1
}
get_output_dir() {
dir=${1%/*}
if [ "$dir" = "$1" ]; then
dir=.
fi
dir=$(cd $dir; pwd)
echo $TMPD/$CMT${dir#$SRCTREE}
}
do_objdump() {
dir=$(get_output_dir $1)
base=${1##*/}
stripped=$dir/${base%.o}.stripped
dis=$dir/${base%.o}.dis
[ ! -d "$dir" ] && mkdir -p $dir
# remove addresses for a cleaner diff
# http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and
$STRIP -g $1 -R __bug_table -R .note -R .comment -o $stripped
$OBJDUMP -D $stripped | sed -e "s/^[[:space:]]\+[0-9a-f]\+//" -e "s:^$stripped:$1:" > $dis
}
dorecord() {
[ $# -eq 0 ] && usage
FILES="$*"
CMT="`git rev-parse --short HEAD`"
STRIP="${CROSS_COMPILE}strip"
OBJDUMP="${CROSS_COMPILE}objdump"
for d in $FILES; do
if [ -d "$d" ]; then
for f in $(find $d -name '*.o')
do
do_objdump $f
done
else
do_objdump $d
fi
done
}
dodiff() {
[ $# -ne 2 ] && [ $# -ne 0 ] && usage
if [ $# -eq 0 ]; then
SRC="`git rev-parse --short HEAD^`"
DST="`git rev-parse --short HEAD`"
else
SRC="`git rev-parse --short $1`"
DST="`git rev-parse --short $2`"
fi
DIFF="`which colordiff`"
if [ ${#DIFF} -eq 0 ] || [ ! -x "$DIFF" ]; then
DIFF="`which diff`"
fi
SRCD="$TMPD/$SRC"
DSTD="$TMPD/$DST"
if [ ! -d "$SRCD" ]; then
echo >&2 "ERROR: $SRCD doesn't exist"
exit 1
fi
if [ ! -d "$DSTD" ]; then
echo >&2 "ERROR: $DSTD doesn't exist"
exit 1
fi
$DIFF -Nurd $SRCD $DSTD
}
doclean() {
[ $# -eq 0 ] && usage
[ $# -gt 1 ] && usage
if [ "x$1" = "xall" ]; then
rm -rf $TMPD/*
else
CMT="`git rev-parse --short $1`"
if [ -d "$TMPD/$CMT" ]; then
rm -rf $TMPD/$CMT
else
echo >&2 "$CMT not found"
fi
fi
}
[ $# -eq 0 ] && usage
case "$1" in
record)
shift
dorecord $*
;;
diff)
shift
dodiff $*
;;
clean)
shift
doclean $*
;;
*)
echo >&2 "Unrecognized command '$1'"
exit 1
;;
esac
Computing file changes ...
