UBSAN: undefined-behaviour in xprt_reset_majortimeo

Status: upstream: reported C repro on 2020/09/20 21:06
Reported-by: syzbot+ca2e0e545f9a1ba6a74c@syzkaller.appspotmail.com
First crash: 2163d, last: 2132d
Fix bisection: failed (error log, bisect log)
  

Sample crash report:
audit: type=1400 audit(1601851949.391:8): avc:  denied  { execmem } for  pid=6500 comm="syz-executor001" 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/sunrpc/xprt.c:568:22
shift exponent 536871552 is too large for 64-bit type 'long unsigned int'
CPU: 1 PID: 6500 Comm: syz-executor001 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
 xprt_reset_majortimeo+0x2f8/0x3b0 net/sunrpc/xprt.c:568
 xprt_request_init net/sunrpc/xprt.c:1290 [inline]
 xprt_do_reserve+0x438/0x530 net/sunrpc/xprt.c:1300
 xprt_reserve+0x129/0x1f0 net/sunrpc/xprt.c:1322
 __rpc_execute+0x1f7/0xb80 net/sunrpc/sched.c:783
 rpc_execute+0x242/0x370 net/sunrpc/sched.c:851
 rpc_run_task+0x4e3/0x6a0 net/sunrpc/clnt.c:1064
 rpc_call_sync+0xb8/0x190 net/sunrpc/clnt.c:1093
 rpc_ping+0xb5/0x110 net/sunrpc/clnt.c:2527
 rpc_create_xprt+0x313/0x3c0 net/sunrpc/clnt.c:479
 rpc_create+0x31e/0x540 net/sunrpc/clnt.c:587
 nfs_create_rpc_client+0x36f/0x440 fs/nfs/client.c:529
 nfs_init_client fs/nfs/client.c:640 [inline]
 nfs_init_client+0x6d/0x100 fs/nfs/client.c:627
 nfs_get_client+0xf9f/0x13e0 fs/nfs/client.c:431
 nfs_init_server+0x249/0xe10 fs/nfs/client.c:676
 nfs_create_server+0x7a/0x4f0 fs/nfs/client.c:960
 nfs3_create_server+0x1a/0x1b0 fs/nfs/nfs3client.c:51
 nfs_try_mount+0x172/0x940 fs/nfs/super.c:1884
 nfs_fs_mount+0x171f/0x2e8e fs/nfs/super.c:2701
 mount_fs+0xa3/0x318 fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2469 [inline]
 do_mount+0x51c/0x2f10 fs/namespace.c:2799
 ksys_mount+0xcf/0x130 fs/namespace.c:3015
 __do_sys_mount fs/namespace.c:3029 [inline]
 __se_sys_mount fs/namespace.c:3026 [inline]
 __x64_sys_mount+0xba/0x150 fs/namespace.c:3026
 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4403d9
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:00007fff715b1ad8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00000000004403d9
RDX: 0000000020000200 RSI: 00000000200001c0 RDI: 0000000000000000
RBP: 00000000006ca018 R08: 0000000020000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401be0
R13: 0000000000401c70 R14: 0000000000000000 R15: 0000000000000000
================================================================================

Crashes (287):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/10/04 22:54 linux-4.19.y b09c34517e1a 5ef9c291 .config console log report syz C ci2-linux-4-19
2020/09/20 21:22 linux-4.19.y 015e94d0e37b 9564d2e9 .config console log report syz C ci2-linux-4-19
2020/10/21 21:06 linux-4.19.y ad326970d25c 99c64d5c .config console log report info ci2-linux-4-19
2020/10/21 19:04 linux-4.19.y ad326970d25c 99c64d5c .config console log report info ci2-linux-4-19
2020/10/21 17:37 linux-4.19.y ad326970d25c 99c64d5c .config console log report info ci2-linux-4-19
2020/10/21 00:59 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/20 23:32 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/20 21:57 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/20 19:25 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/20 18:05 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/20 16:51 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/20 15:32 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/20 13:20 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/20 08:01 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/19 19:13 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/19 16:47 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/19 07:20 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/19 03:48 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/18 16:02 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/18 09:27 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/18 03:41 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/18 02:31 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/17 19:17 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/17 15:46 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/17 07:30 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/17 06:13 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/17 04:58 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/17 04:06 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/17 00:03 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 21:46 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 18:07 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 11:00 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 04:56 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 03:41 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/15 19:33 linux-4.19.y a1b977b49b66 63869021 .config console log report info ci2-linux-4-19
2020/10/15 15:31 linux-4.19.y a1b977b49b66 63869021 .config console log report info ci2-linux-4-19
2020/10/15 10:23 linux-4.19.y a1b977b49b66 63869021 .config console log report info ci2-linux-4-19
2020/10/15 03:11 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/15 01:12 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/14 21:05 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/14 18:01 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/14 14:18 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/14 05:07 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/14 02:51 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/14 01:41 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/13 22:07 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/09/20 21:05 linux-4.19.y 015e94d0e37b 9564d2e9 .config console log report info ci2-linux-4-19
* Struck through repros no longer work on HEAD.