UBSAN: undefined-behaviour in tcindex_set_parms

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 015e94d0 Linux 4.19.146
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1269d23d900000
kernel config: https://syzkaller.appspot.com/x/.config?x=243dd74ad58a8a57
dashboard link: https://syzkaller.appspot.com/bug?extid=bb2884ea19df6e413901
compiler: gcc (GCC) 10.1.0-syz 20200507

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bb2884...@syzkaller.appspotmail.com

================================================================================
UBSAN: Undefined behaviour in net/sched/cls_tcindex.c:238:29
shift exponent 44 is too large for 32-bit type 'int'
CPU: 1 PID: 22288 Comm: syz-executor.2 Not tainted 4.19.146-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x22c/0x33e lib/dump_stack.c:118
ubsan_epilogue+0xe/0x3a lib/ubsan.c:161
__ubsan_handle_shift_out_of_bounds.cold+0x1c4/0x250 lib/ubsan.c:422
valid_perfect_hash net/sched/cls_tcindex.c:238 [inline]
tcindex_set_parms.cold+0x170/0x22f net/sched/cls_tcindex.c:398
tcindex_change+0x220/0x2f3 net/sched/cls_tcindex.c:518
tc_new_tfilter+0xb38/0x1570 net/sched/cls_api.c:1320
rtnetlink_rcv_msg+0x498/0xc10 net/core/rtnetlink.c:4778
netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2455
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x717/0xcc0 net/netlink/af_netlink.c:1909
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xc7/0x130 net/socket.c:632
___sys_sendmsg+0x7bb/0x8f0 net/socket.c:2115
__sys_sendmsg net/socket.c:2153 [inline]
__do_sys_sendmsg net/socket.c:2162 [inline]
__se_sys_sendmsg net/socket.c:2160 [inline]
__x64_sys_sendmsg+0x132/0x220 net/socket.c:2160
do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45d5f9
Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5bc9bd9c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002cf40 RCX: 000000000045d5f9
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003
RBP: 000000000118d020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007ffdb95508af R14: 00007f5bc9bda9c0 R15: 000000000118cfec
================================================================================
audit: type=1804 audit(1600751187.061:230): pid=22300 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir350630241/syzkaller.5wbvZE/375/bus" dev="sda1" ino=16929 res=1
netlink: 44371 bytes leftover after parsing attributes in process `syz-executor.3'.
netlink: 44199 bytes leftover after parsing attributes in process `syz-executor.3'.
audit: type=1804 audit(1600751188.321:231): pid=22339 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir350630241/syzkaller.5wbvZE/376/bus" dev="sda1" ino=17025 res=1
netlink: 40 bytes leftover after parsing attributes in process `syz-executor.4'.
ptrace attach of "/root/syz-executor.4"[22370] was attempted by "/root/syz-executor.4"[22371]
netlink: 44183 bytes leftover after parsing attributes in process `syz-executor.3'.
audit: type=1804 audit(1600751189.471:232): pid=22382 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir350630241/syzkaller.5wbvZE/377/bus" dev="sda1" ino=17041 res=1
xt_CT: netfilter: NOTRACK target is deprecated, use CT instead or upgrade iptables
audit: type=1804 audit(1600751190.841:233): pid=22422 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir350630241/syzkaller.5wbvZE/378/bus" dev="sda1" ino=17041 res=1
md: md0 stopped.
kvm [22454]: vcpu0, guest rIP: 0xcc ignored wrmsr: 0x11e data 0xbe702111
audit: type=1804 audit(1600751192.631:234): pid=22475 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir350630241/syzkaller.5wbvZE/379/bus" dev="sda1" ino=17025 res=1
kvm [22454]: vcpu0, guest rIP: 0xcc ignored wrmsr: 0x11e data 0xbe702111
audit: type=1804 audit(1600751193.611:235): pid=22519 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir350630241/syzkaller.5wbvZE/380/bus" dev="sda1" ino=17089 res=1
audit: type=1804 audit(1600751194.561:236): pid=22548 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir350630241/syzkaller.5wbvZE/381/bus" dev="sda1" ino=17093 res=1
audit: type=1804 audit(1600751195.521:237): pid=22580 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir350630241/syzkaller.5wbvZE/382/bus" dev="sda1" ino=17362 res=1
audit: type=1804 audit(1600751196.771:238): pid=22617 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir350630241/syzkaller.5wbvZE/383/bus" dev="sda1" ino=16376 res=1


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 015e94d0 Linux 4.19.146
git tree: linux-4.19.y

console output: https://syzkaller.appspot.com/x/log.txt?x=11dc25d9900000

kernel config: https://syzkaller.appspot.com/x/.config?x=243dd74ad58a8a57
dashboard link: https://syzkaller.appspot.com/bug?extid=bb2884ea19df6e413901
compiler: gcc (GCC) 10.1.0-syz 20200507

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10b73cc3900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15ae929b900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bb2884...@syzkaller.appspotmail.com

audit: type=1400 audit(1600752379.624:8): avc: denied { execmem } for pid=6489 comm="syz-executor817" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.

================================================================================
UBSAN: Undefined behaviour in net/sched/cls_tcindex.c:238:29
shift exponent 44 is too large for 32-bit type 'int'

CPU: 0 PID: 6491 Comm: syz-executor817 Not tainted 4.19.146-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x22c/0x33e lib/dump_stack.c:118
ubsan_epilogue+0xe/0x3a lib/ubsan.c:161
__ubsan_handle_shift_out_of_bounds.cold+0x1c4/0x250 lib/ubsan.c:422
valid_perfect_hash net/sched/cls_tcindex.c:238 [inline]
tcindex_set_parms.cold+0x170/0x22f net/sched/cls_tcindex.c:398
tcindex_change+0x220/0x2f3 net/sched/cls_tcindex.c:518
tc_new_tfilter+0xb38/0x1570 net/sched/cls_api.c:1320
rtnetlink_rcv_msg+0x498/0xc10 net/core/rtnetlink.c:4778
netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2455
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x717/0xcc0 net/netlink/af_netlink.c:1909
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xc7/0x130 net/socket.c:632
___sys_sendmsg+0x7bb/0x8f0 net/socket.c:2115
__sys_sendmsg net/socket.c:2153 [inline]
__do_sys_sendmsg net/socket.c:2162 [inline]
__se_sys_sendmsg net/socket.c:2160 [inline]
__x64_sys_sendmsg+0x132/0x220 net/socket.c:2160
do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

RIP: 0033:0x441629
Code: e8 fc ab 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 1b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdf6c12348 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441629

RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003

RBP: 000000000000a1c1 R08: 00000000004002c8 R09: 00000000004002c8
R10: 0000000020000080 R11: 0000000000000246 R12: 00000000004023d0
R13: 0000000000402460 R14: 0000000000000000 R15: 0000000000000000
================================================================================
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
nla_parse: 830 callbacks suppressed
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor817'.
------------[ cut here ]------------
ODEBUG: free active (active state 0) object type: work_struct hint: tcindex_destroy_rexts_work+0x0/0x20 include/net/pkt_cls.h:301
WARNING: CPU: 1 PID: 46 at lib/debugobjects.c:325 debug_print_object+0x194/0x2b0 lib/debugobjects.c:325

[syzbot]

syzbot suspects this issue was fixed by commit:

commit 22c1b22672f3c56289ea91cf5eaffa61db3e4b2e
Author: Eric Dumazet <edum...@google.com>
Date: Thu Jan 14 18:52:29 2021 +0000

net_sched: avoid shift-out-of-bounds in tcindex_set_parms()

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12a4bca8d00000
start commit: a1b977b4 Linux 4.19.150
git tree: linux-4.19.y
kernel config: https://syzkaller.appspot.com/x/.config?x=c14008c8da1ca4d4
dashboard link: https://syzkaller.appspot.com/bug?extid=bb2884ea19df6e413901
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=107e7bd0500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14c1a7e7900000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: net_sched: avoid shift-out-of-bounds in tcindex_set_parms()

For information about bisection process see: https://goo.gl/tpsmEJ#bisection