Subject: [syzbot] UBSAN: shift-out-of-bounds in xfrm_selector_match

From: syzbot <[email-masked]>
Date: Thu, 10 Jun 2021 12:19:26 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    13c62f53 net/sched: act_ct: handle DNAT tuple collision
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=16635470300000
kernel config:  https://syzkaller.appspot.com/x/.config?x=770708ea7cfd4916
dashboard link: https://syzkaller.appspot.com/bug?extid=e4c1dd36fc6b98c50859

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: [email-masked]

UBSAN: shift-out-of-bounds in ./include/net/xfrm.h:838:23
shift exponent -64 is negative
CPU: 0 PID: 12625 Comm: syz-executor.1 Not tainted 5.13.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 ubsan_epilogue+0xb/0x5a lib/ubsan.c:148
 __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x181 lib/ubsan.c:327
 addr4_match include/net/xfrm.h:838 [inline]
 __xfrm4_selector_match net/xfrm/xfrm_policy.c:201 [inline]
 xfrm_selector_match.cold+0x35/0x3a net/xfrm/xfrm_policy.c:227
 xfrm_state_look_at+0x16d/0x440 net/xfrm/xfrm_state.c:1022
 xfrm_state_find+0x16c0/0x4d10 net/xfrm/xfrm_state.c:1096
 xfrm_tmpl_resolve_one net/xfrm/xfrm_policy.c:2394 [inline]
 xfrm_tmpl_resolve+0x2f3/0xd40 net/xfrm/xfrm_policy.c:2439
 xfrm_resolve_and_create_bundle+0x123/0x2590 net/xfrm/xfrm_policy.c:2729
 xfrm_lookup_with_ifid+0x227/0x20e0 net/xfrm/xfrm_policy.c:3063
 xfrm_lookup net/xfrm/xfrm_policy.c:3187 [inline]
 xfrm_lookup_route+0x36/0x1e0 net/xfrm/xfrm_policy.c:3198
 ip_route_output_flow+0x114/0x150 net/ipv4/route.c:2733
 udp_sendmsg+0x1a2f/0x2730 net/ipv4/udp.c:1206
 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:821
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 ____sys_sendmsg+0x331/0x810 net/socket.c:2350
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
 __sys_sendmmsg+0x195/0x470 net/socket.c:2490
 __do_sys_sendmmsg net/socket.c:2519 [inline]
 __se_sys_sendmmsg net/socket.c:2516 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2516
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb1023dd188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 000000000800001d RSI: 0000000020007fc0 RDI: 0000000000000003
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffc4542d68f R14: 00007fb1023dd300 R15: 0000000000022000
================================================================================

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