UBSAN: undefined-behaviour in qdisc_get_rtab

Status: upstream: reported C repro on 2020/09/17 01:46
Reported-by: syzbot+410eb2a3eae45d8d0dc0@syzkaller.appspotmail.com
First crash: 2168d, last: 2134d
Fix bisection: failed (error log, bisect log)
  

Sample crash report:
audit: type=1400 audit(1601822820.481:8): avc:  denied  { execmem } for  pid=6490 comm="syz-executor067" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1
================================================================================
UBSAN: Undefined behaviour in net/sched/sch_api.c:375:22
shift exponent 255 is too large for 32-bit type 'int'
CPU: 1 PID: 6490 Comm: syz-executor067 Not tainted 4.19.149-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
 __detect_linklayer net/sched/sch_api.c:375 [inline]
 qdisc_get_rtab.cold+0x1d/0x8e net/sched/sch_api.c:421
 tbf_change+0x99d/0x1230 net/sched/sch_tbf.c:325
 tbf_init+0x91/0xc4 net/sched/sch_tbf.c:433
 qdisc_create+0x534/0x1080 net/sched/sch_api.c:1155
 tc_modify_qdisc+0x4c0/0x195b net/sched/sch_api.c:1571
 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: 0033:0x440fe9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc1d7faa58 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440fe9
RDX: 0000000000000000 RSI: 0000000020000800 RDI: 0000000000000004
RBP: 00000000006cb018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004027f0
R13: 0000000000402880 R14: 0000000000000000 R15: 0000000000000000
================================================================================
================================================================================
UBSAN: Undefined behaviour in net/sched/sch_api.c:376:24
shift exponent 255 is too large for 32-bit type 'int'
CPU: 1 PID: 6490 Comm: syz-executor067 Not tainted 4.19.149-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
 __detect_linklayer net/sched/sch_api.c:376 [inline]
 qdisc_get_rtab.cold+0x7f/0x8e net/sched/sch_api.c:421
 tbf_change+0x99d/0x1230 net/sched/sch_tbf.c:325
 tbf_init+0x91/0xc4 net/sched/sch_tbf.c:433
 qdisc_create+0x534/0x1080 net/sched/sch_api.c:1155
 tc_modify_qdisc+0x4c0/0x195b net/sched/sch_api.c:1571
 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: 0033:0x440fe9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc1d7faa58 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffd

Crashes (754):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/10/04 14:48 linux-4.19.y b09c34517e1a 5ef9c291 .config console log report syz C ci2-linux-4-19
2020/09/20 17:37 linux-4.19.y 015e94d0e37b 9564d2e9 .config console log report syz C ci2-linux-4-19
2020/10/21 21:05 linux-4.19.y ad326970d25c 99c64d5c .config console log report info ci2-linux-4-19
2020/10/21 12:29 linux-4.19.y ad326970d25c 99c64d5c .config console log report info ci2-linux-4-19
2020/10/21 11:23 linux-4.19.y ad326970d25c 99c64d5c .config console log report info ci2-linux-4-19
2020/10/21 07:24 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/21 04:58 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/21 00:05 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/20 22:11 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/19 19:36 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/19 10:31 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/19 09:26 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/19 06:55 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/18 23:17 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/18 15:10 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/17 21:19 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/17 12:24 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/16 18:42 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 13:39 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 11:29 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 09:52 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 09:47 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 08:14 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 06:47 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 05:16 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 04:05 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 00:48 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/15 23:38 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/15 22:05 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/15 20:20 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/15 15:06 linux-4.19.y a1b977b49b66 63869021 .config console log report info ci2-linux-4-19
2020/10/15 09:24 linux-4.19.y a1b977b49b66 63869021 .config console log report info ci2-linux-4-19
2020/10/14 13:57 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/13 21:46 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/13 20:21 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/13 12:05 linux-4.19.y a1b977b49b66 bd69ee0d .config console log report info ci2-linux-4-19
2020/10/13 08:54 linux-4.19.y a1b977b49b66 bd69ee0d .config console log report info ci2-linux-4-19
2020/10/13 04:36 linux-4.19.y a1b977b49b66 d32b0bbf .config console log report info ci2-linux-4-19
2020/10/12 16:51 linux-4.19.y a1b977b49b66 d32b0bbf .config console log report info ci2-linux-4-19
2020/10/12 15:49 linux-4.19.y a1b977b49b66 d32b0bbf .config console log report info ci2-linux-4-19
2020/10/12 11:20 linux-4.19.y a1b977b49b66 4a77ae0b .config console log report info ci2-linux-4-19
2020/10/11 14:49 linux-4.19.y a1b977b49b66 4a77ae0b .config console log report info ci2-linux-4-19
2020/10/11 05:17 linux-4.19.y a1b977b49b66 4a77ae0b .config console log report info ci2-linux-4-19
2020/10/10 21:37 linux-4.19.y a1b977b49b66 4a77ae0b .config console log report info ci2-linux-4-19
2020/10/10 10:17 linux-4.19.y a1b977b49b66 b74c49a6 .config console log report info ci2-linux-4-19
2020/10/10 09:53 linux-4.19.y a1b977b49b66 b74c49a6 .config console log report info ci2-linux-4-19
2020/09/17 01:45 linux-4.19.y a87f96283793 8247808b .config console log report info ci2-linux-4-19
* Struck through repros no longer work on HEAD.