UBSAN: undefined-behaviour in hash_ipmark_create

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syzbot

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Sep 21, 2020, 2:46:16 AM9/21/20
to syzkaller...@googlegroups.com
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=16b61fb5900000
kernel config: https://syzkaller.appspot.com/x/.config?x=243dd74ad58a8a57
dashboard link: https://syzkaller.appspot.com/bug?extid=2ea4f39569af9b206178
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+2ea4f3...@syzkaller.appspotmail.com

================================================================================
UBSAN: Undefined behaviour in net/netfilter/ipset/ip_set_hash_gen.h:125:6
shift exponent 32 is too large for 32-bit type 'unsigned int'
CPU: 0 PID: 17465 Comm: syz-executor.1 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
htable_bits net/netfilter/ipset/ip_set_hash_gen.h:125 [inline]
hash_ipmark_create.cold+0x19/0x27 net/netfilter/ipset/ip_set_hash_gen.h:1290
ip_set_create+0x70e/0x1380 net/netfilter/ipset/ip_set_core.c:940
nfnetlink_rcv_msg+0xeff/0x1210 net/netfilter/nfnetlink.c:233
netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2455
nfnetlink_rcv+0x1b2/0x41b net/netfilter/nfnetlink.c:565
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
sock_no_sendpage+0xf5/0x140 net/core/sock.c:2668
kernel_sendpage net/socket.c:3378 [inline]
sock_sendpage+0xdf/0x140 net/socket.c:847
pipe_to_sendpage+0x268/0x330 fs/splice.c:452
splice_from_pipe_feed fs/splice.c:503 [inline]
__splice_from_pipe+0x3af/0x820 fs/splice.c:627
splice_from_pipe fs/splice.c:662 [inline]
generic_splice_sendpage+0xd4/0x140 fs/splice.c:833
do_splice_from fs/splice.c:852 [inline]
do_splice fs/splice.c:1154 [inline]
__do_sys_splice fs/splice.c:1428 [inline]
__se_sys_splice+0xf31/0x15f0 fs/splice.c:1408
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:00007fc830214c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 0000000000033a00 RCX: 000000000045d5f9
RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 000000000118cf98 R08: 0000000100000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007fff0a1dfa4f R14: 00007fc8302159c0 R15: 000000000118cf4c
================================================================================


---
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See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot

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Sep 21, 2020, 3:00:24 AM9/21/20
to syzkaller...@googlegroups.com
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=11f909d9900000
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15eee6c5900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=159b1e73900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2ea4f3...@syzkaller.appspotmail.com

audit: type=1400 audit(1600671490.433:8): avc: denied { execmem } for pid=6484 comm="syz-executor344" 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/netfilter/ipset/ip_set_hash_gen.h:125:6
shift exponent 32 is too large for 32-bit type 'unsigned int'
CPU: 1 PID: 6484 Comm: syz-executor344 Not tainted 4.19.146-syzkaller #0
RIP: 0033:0x4404d9
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:00007ffcb6944b48 EFLAGS: 00000246 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004404d9
RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000100000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401ce0
R13: 0000000000401d70 R14: 0000000000000000 R15: 0000000000000000
=======================================================================

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