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WARNING: suspicious RCU usage in rhltable_lookup

Status: upstream: reported C repro on 2025/01/29 10:23
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+3b9b5f6a4cc6433864e0@syzkaller.appspotmail.com
First crash: 47d, last: 1h11m
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/03/16 linux-5.15.y (ToT) 0c935c049b5c C [report] WARNING: suspicious RCU usage in rhltable_lookup
2025/03/16 upstream (ToT) d1275e99d1c4 C Didn't crash

Sample crash report:
=============================
WARNING: suspicious RCU usage
5.15.178-syzkaller #0 Not tainted
-----------------------------
include/linux/rhashtable.h:594 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor907/4164:
 #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: ip_mroute_setsockopt+0x15e/0x1540 net/ipv4/ipmr.c:1362

stack backtrace:
CPU: 0 PID: 4164 Comm: syz-executor907 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 __rhashtable_lookup include/linux/rhashtable.h:594 [inline]
 rhltable_lookup+0x7e5/0x7f0 include/linux/rhashtable.h:688
 mr_mfc_find_any_parent+0xb4/0x1e0 net/ipv4/ipmr_base.c:83
 ip_mr_forward+0x213/0x1010 net/ipv4/ipmr.c:1949
 ipmr_cache_resolve net/ipv4/ipmr.c:1003 [inline]
 ipmr_mfc_add+0x243a/0x2df0 net/ipv4/ipmr.c:1262
 ip_mroute_setsockopt+0xfa9/0x1540 net/ipv4/ipmr.c:1459
 do_ip_setsockopt net/ipv4/ip_sockglue.c:947 [inline]
 ip_setsockopt+0x5b3/0x3fb0 net/ipv4/ip_sockglue.c:1430
 __sys_setsockopt+0x57e/0x990 net/socket.c:2203
 __do_sys_setsockopt net/socket.c:2214 [inline]
 __se_sys_setsockopt net/socket.c:2211 [inline]
 __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2211
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7febdb042669
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc26360078 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007febdb09018d RCX: 00007febdb042669
RDX: 00000000000000d2 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007febdb09015d R08: 000000000000003c R09: 0000000000000000
R10: 0000400000000200 R11: 0000000000000246 R12: 00007febdb0900c5
R13: 00007ffc263600a0 R14: 00007febdb09545c R15: 00007febdb090004
 </TASK>

=============================
WARNING: suspicious RCU usage
5.15.178-syzkaller #0 Not tainted
-----------------------------
include/linux/rhashtable.h:369 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor907/4164:
 #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: ip_mroute_setsockopt+0x15e/0x1540 net/ipv4/ipmr.c:1362

stack backtrace:
CPU: 0 PID: 4164 Comm: syz-executor907 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 rht_ptr_rcu include/linux/rhashtable.h:369 [inline]
 __rhashtable_lookup include/linux/rhashtable.h:599 [inline]
 rhltable_lookup+0x582/0x7f0 include/linux/rhashtable.h:688
 mr_mfc_find_any_parent+0xb4/0x1e0 net/ipv4/ipmr_base.c:83
 ip_mr_forward+0x213/0x1010 net/ipv4/ipmr.c:1949
 ipmr_cache_resolve net/ipv4/ipmr.c:1003 [inline]
 ipmr_mfc_add+0x243a/0x2df0 net/ipv4/ipmr.c:1262
 ip_mroute_setsockopt+0xfa9/0x1540 net/ipv4/ipmr.c:1459
 do_ip_setsockopt net/ipv4/ip_sockglue.c:947 [inline]
 ip_setsockopt+0x5b3/0x3fb0 net/ipv4/ip_sockglue.c:1430
 __sys_setsockopt+0x57e/0x990 net/socket.c:2203
 __do_sys_setsockopt net/socket.c:2214 [inline]
 __se_sys_setsockopt net/socket.c:2211 [inline]
 __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2211
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7febdb042669
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc26360078 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007febdb09018d RCX: 00007febdb042669
RDX: 00000000000000d2 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007febdb09015d R08: 000000000000003c R09: 0000000000000000
R10: 0000400000000200 R11: 0000000000000246 R12: 00007febdb0900c5
R13: 00007ffc263600a0 R14: 00007febdb09545c R15: 00007febdb090004
 </TASK>

=============================
WARNING: suspicious RCU usage
5.15.178-syzkaller #0 Not tainted
-----------------------------
include/linux/rhashtable.h:614 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor907/4164:
 #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: ip_mroute_setsockopt+0x15e/0x1540 net/ipv4/ipmr.c:1362

stack backtrace:
CPU: 0 PID: 4164 Comm: syz-executor907 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 __rhashtable_lookup include/linux/rhashtable.h:614 [inline]
 rhltable_lookup+0x676/0x7f0 include/linux/rhashtable.h:688
 mr_mfc_find_any_parent+0xb4/0x1e0 net/ipv4/ipmr_base.c:83
 ip_mr_forward+0x213/0x1010 net/ipv4/ipmr.c:1949
 ipmr_cache_resolve net/ipv4/ipmr.c:1003 [inline]
 ipmr_mfc_add+0x243a/0x2df0 net/ipv4/ipmr.c:1262
 ip_mroute_setsockopt+0xfa9/0x1540 net/ipv4/ipmr.c:1459
 do_ip_setsockopt net/ipv4/ip_sockglue.c:947 [inline]
 ip_setsockopt+0x5b3/0x3fb0 net/ipv4/ip_sockglue.c:1430
 __sys_setsockopt+0x57e/0x990 net/socket.c:2203
 __do_sys_setsockopt net/socket.c:2214 [inline]
 __se_sys_setsockopt net/socket.c:2211 [inline]
 __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2211
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7febdb042669
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc26360078 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007febdb09018d RCX: 00007febdb042669
RDX: 00000000000000d2 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007febdb09015d R08: 000000000000003c R09: 0000000000000000
R10: 0000400000000200 R11: 0000000000000246 R12: 00007febdb0900c5
R13: 00007ffc263600a0 R14: 00007febdb09545c R15: 00007febdb090004
 </TASK>

Crashes (479):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/01 04:38 linux-5.15.y c16c81c81336 67cf5345 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/01/29 11:05 linux-5.15.y 003148680b79 865ef71e .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/18 07:32 linux-5.15.y 0c935c049b5c ce3352cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/18 06:06 linux-5.15.y 0c935c049b5c ce3352cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/17 18:40 linux-5.15.y 0c935c049b5c 948c34e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/17 15:33 linux-5.15.y 0c935c049b5c 948c34e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/17 15:32 linux-5.15.y 0c935c049b5c 948c34e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/17 14:30 linux-5.15.y 0c935c049b5c 948c34e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/15 19:40 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/15 08:55 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/15 03:40 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/15 03:37 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/15 01:30 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/14 10:15 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/13 21:29 linux-5.15.y 0c935c049b5c 44be8b44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/13 20:03 linux-5.15.y 0c935c049b5c 44be8b44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/13 04:00 linux-5.15.y c16c81c81336 1a5d9317 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/10 22:33 linux-5.15.y c16c81c81336 16256247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/10 12:38 linux-5.15.y c16c81c81336 163f510d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/10 08:48 linux-5.15.y c16c81c81336 163f510d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/10 05:49 linux-5.15.y c16c81c81336 163f510d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/09 07:11 linux-5.15.y c16c81c81336 163f510d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/08 21:28 linux-5.15.y c16c81c81336 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/08 20:06 linux-5.15.y c16c81c81336 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/08 19:03 linux-5.15.y c16c81c81336 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/08 01:30 linux-5.15.y c16c81c81336 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/03/18 04:55 linux-5.15.y 0c935c049b5c ce3352cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/18 02:46 linux-5.15.y 0c935c049b5c ce3352cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/17 13:13 linux-5.15.y 0c935c049b5c 948c34e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/16 23:09 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/16 23:09 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/16 11:51 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/16 09:56 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/16 03:07 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/15 18:46 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/15 14:35 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/15 05:01 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/14 16:32 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/14 09:52 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/14 05:51 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/13 18:12 linux-5.15.y 0c935c049b5c 44be8b44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/13 05:46 linux-5.15.y c16c81c81336 1a5d9317 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/13 05:44 linux-5.15.y c16c81c81336 1a5d9317 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/13 01:06 linux-5.15.y c16c81c81336 1a5d9317 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/12 06:47 linux-5.15.y c16c81c81336 ee70e6db .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/11 00:21 linux-5.15.y c16c81c81336 16256247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/10 22:24 linux-5.15.y c16c81c81336 16256247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/08 23:11 linux-5.15.y c16c81c81336 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/08 23:08 linux-5.15.y c16c81c81336 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/03/08 18:27 linux-5.15.y c16c81c81336 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/01/29 10:22 linux-5.15.y 003148680b79 865ef71e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
* Struck through repros no longer work on HEAD.