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WARNING: suspicious RCU usage in rhltable_lookup

Status: upstream: reported C repro on 2025/01/29 10:23
Reported-by: syzbot+3b9b5f6a4cc6433864e0@syzkaller.appspotmail.com
First crash: 7d11h, last: 10h48m
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2025/01/29 upstream (ToT) 05dbaf8dd8bf C Failed due to an error; will retry later

Sample crash report:
=============================
WARNING: suspicious RCU usage
5.15.177-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-executor254/4020:
 #0: ffff800016cb4b68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:72

stack backtrace:
CPU: 0 PID: 4020 Comm: syz-executor254 Not tainted 5.15.177-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 lockdep_rcu_suspicious+0x188/0x1e0 kernel/locking/lockdep.c:6571
 __rhashtable_lookup include/linux/rhashtable.h:594 [inline]
 rhltable_lookup+0x6a0/0x6a8 include/linux/rhashtable.h:688
 mr_mfc_find_any_parent+0xe8/0x20c net/ipv4/ipmr_base.c:83
 ip_mr_forward+0x214/0xe10 net/ipv4/ipmr.c:1949
 ipmr_cache_resolve net/ipv4/ipmr.c:1003 [inline]
 ipmr_mfc_add+0x1ea0/0x28a0 net/ipv4/ipmr.c:1262
 ip_mroute_setsockopt+0xaf8/0xe94 net/ipv4/ipmr.c:1459
 do_ip_setsockopt net/ipv4/ip_sockglue.c:947 [inline]
 ip_setsockopt+0x618/0x32cc net/ipv4/ip_sockglue.c:1430
 raw_setsockopt+0x104/0x2b8 net/ipv4/raw.c:863
 sock_common_setsockopt+0xb0/0xcc net/core/sock.c:3448
 __sys_setsockopt+0x3a8/0x6b4 net/socket.c:2203
 __do_sys_setsockopt net/socket.c:2214 [inline]
 __se_sys_setsockopt net/socket.c:2211 [inline]
 __arm64_sys_setsockopt+0xb8/0xd4 net/socket.c:2211
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

=============================
WARNING: suspicious RCU usage
5.15.177-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-executor254/4020:
 #0: ffff800016cb4b68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:72

stack backtrace:
CPU: 0 PID: 4020 Comm: syz-executor254 Not tainted 5.15.177-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 lockdep_rcu_suspicious+0x188/0x1e0 kernel/locking/lockdep.c:6571
 rht_ptr_rcu include/linux/rhashtable.h:369 [inline]
 __rhashtable_lookup include/linux/rhashtable.h:599 [inline]
 rhltable_lookup+0x45c/0x6a8 include/linux/rhashtable.h:688
 mr_mfc_find_any_parent+0xe8/0x20c net/ipv4/ipmr_base.c:83
 ip_mr_forward+0x214/0xe10 net/ipv4/ipmr.c:1949
 ipmr_cache_resolve net/ipv4/ipmr.c:1003 [inline]
 ipmr_mfc_add+0x1ea0/0x28a0 net/ipv4/ipmr.c:1262
 ip_mroute_setsockopt+0xaf8/0xe94 net/ipv4/ipmr.c:1459
 do_ip_setsockopt net/ipv4/ip_sockglue.c:947 [inline]
 ip_setsockopt+0x618/0x32cc net/ipv4/ip_sockglue.c:1430
 raw_setsockopt+0x104/0x2b8 net/ipv4/raw.c:863
 sock_common_setsockopt+0xb0/0xcc net/core/sock.c:3448
 __sys_setsockopt+0x3a8/0x6b4 net/socket.c:2203
 __do_sys_setsockopt net/socket.c:2214 [inline]
 __se_sys_setsockopt net/socket.c:2211 [inline]
 __arm64_sys_setsockopt+0xb8/0xd4 net/socket.c:2211
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

=============================
WARNING: suspicious RCU usage
5.15.177-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-executor254/4020:
 #0: ffff800016cb4b68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:72

stack backtrace:
CPU: 0 PID: 4020 Comm: syz-executor254 Not tainted 5.15.177-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 lockdep_rcu_suspicious+0x188/0x1e0 kernel/locking/lockdep.c:6571
 __rhashtable_lookup include/linux/rhashtable.h:614 [inline]
 rhltable_lookup+0x554/0x6a8 include/linux/rhashtable.h:688
 mr_mfc_find_any_parent+0xe8/0x20c net/ipv4/ipmr_base.c:83
 ip_mr_forward+0x214/0xe10 net/ipv4/ipmr.c:1949
 ipmr_cache_resolve net/ipv4/ipmr.c:1003 [inline]
 ipmr_mfc_add+0x1ea0/0x28a0 net/ipv4/ipmr.c:1262
 ip_mroute_setsockopt+0xaf8/0xe94 net/ipv4/ipmr.c:1459
 do_ip_setsockopt net/ipv4/ip_sockglue.c:947 [inline]
 ip_setsockopt+0x618/0x32cc net/ipv4/ip_sockglue.c:1430
 raw_setsockopt+0x104/0x2b8 net/ipv4/raw.c:863
 sock_common_setsockopt+0xb0/0xcc net/core/sock.c:3448
 __sys_setsockopt+0x3a8/0x6b4 net/socket.c:2203
 __do_sys_setsockopt net/socket.c:2214 [inline]
 __se_sys_setsockopt net/socket.c:2211 [inline]
 __arm64_sys_setsockopt+0xb8/0xd4 net/socket.c:2211
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Crashes (31):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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
2025/02/05 11:05 linux-5.15.y c16c81c81336 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/02/05 11:05 linux-5.15.y c16c81c81336 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/02/05 04:43 linux-5.15.y c16c81c81336 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/02/05 04:43 linux-5.15.y c16c81c81336 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/02/02 15:13 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/02/02 15:13 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/02/02 14:26 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/02/02 14:26 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/02/02 13:20 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/02/02 02:57 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/02/02 02:57 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/01/29 19:17 linux-5.15.y 003148680b79 136953f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/01/29 19:16 linux-5.15.y 003148680b79 136953f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/01/29 19:13 linux-5.15.y 003148680b79 136953f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/01/29 18:02 linux-5.15.y 003148680b79 136953f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/01/29 18:01 linux-5.15.y 003148680b79 136953f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in rhltable_lookup
2025/02/05 10:56 linux-5.15.y c16c81c81336 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/02/04 12:05 linux-5.15.y c16c81c81336 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/02/04 12:05 linux-5.15.y c16c81c81336 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/02/03 09:52 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/02/03 09:52 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/02/03 09:49 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/02/03 09:49 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/02/02 10:05 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/02/02 10:03 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/02/02 06:19 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/02/02 06:18 linux-5.15.y c16c81c81336 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING: suspicious RCU usage in rhltable_lookup
2025/02/02 02:32 linux-5.15.y c16c81c81336 568559e4 .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 10:27 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
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.