Re: [syzbot] [net?] possible deadlock in rtnl_lock (8)
From: syzbot
Date: Sun Sep 08 2024 - 04:12:37 EST
syzbot has found a reproducer for the following issue on:
HEAD commit: df54f4a16f82 Merge branch 'for-next/core' into for-kernelci
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=12bdabc7980000
kernel config: https://syzkaller.appspot.com/x/.config?x=dde5a5ba8d41ee9e
dashboard link: https://syzkaller.appspot.com/bug?extid=51cf7cc5f9ffc1006ef2
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1798589f980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10a30e00580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/aa2eb06e0aea/disk-df54f4a1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/14728733d385/vmlinux-df54f4a1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/99816271407d/Image-df54f4a1.gz.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+51cf7cc5f9ffc1006ef2@xxxxxxxxxxxxxxxxxxxxxxxxx
======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc5-syzkaller-gdf54f4a16f82 #0 Not tainted
------------------------------------------------------
syz-executor272/6388 is trying to acquire lock:
ffff8000923b6ce8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:79
but task is already holding lock:
ffff0000dc408a50 (&smc->clcsock_release_lock){+.+.}-{3:3}, at: smc_setsockopt+0x178/0x10fc net/smc/af_smc.c:3064
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&smc->clcsock_release_lock){+.+.}-{3:3}:
__mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608
__mutex_lock kernel/locking/mutex.c:752 [inline]
mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804
smc_switch_to_fallback+0x48/0xa80 net/smc/af_smc.c:902
smc_sendmsg+0xfc/0x9f8 net/smc/af_smc.c:2779
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
__sys_sendto+0x374/0x4f4 net/socket.c:2204
__do_sys_sendto net/socket.c:2216 [inline]
__se_sys_sendto net/socket.c:2212 [inline]
__arm64_sys_sendto+0xd8/0xf8 net/socket.c:2212
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
-> #1 (sk_lock-AF_INET){+.+.}-{0:0}:
lock_sock_nested net/core/sock.c:3543 [inline]
lock_sock include/net/sock.h:1607 [inline]
sockopt_lock_sock+0x88/0x148 net/core/sock.c:1061
do_ip_setsockopt+0x1438/0x346c net/ipv4/ip_sockglue.c:1078
ip_setsockopt+0x80/0x128 net/ipv4/ip_sockglue.c:1417
raw_setsockopt+0x100/0x294 net/ipv4/raw.c:845
sock_common_setsockopt+0xb0/0xcc net/core/sock.c:3735
do_sock_setsockopt+0x2a0/0x4e0 net/socket.c:2324
__sys_setsockopt+0x128/0x1a8 net/socket.c:2347
__do_sys_setsockopt net/socket.c:2356 [inline]
__se_sys_setsockopt net/socket.c:2353 [inline]
__arm64_sys_setsockopt+0xb8/0xd4 net/socket.c:2353
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
-> #0 (rtnl_mutex){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3133 [inline]
check_prevs_add kernel/locking/lockdep.c:3252 [inline]
validate_chain kernel/locking/lockdep.c:3868 [inline]
__lock_acquire+0x33d8/0x779c kernel/locking/lockdep.c:5142
lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5759
__mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608
__mutex_lock kernel/locking/mutex.c:752 [inline]
mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804
rtnl_lock+0x20/0x2c net/core/rtnetlink.c:79
do_ip_setsockopt+0xe8c/0x346c net/ipv4/ip_sockglue.c:1077
ip_setsockopt+0x80/0x128 net/ipv4/ip_sockglue.c:1417
tcp_setsockopt+0xcc/0xe8 net/ipv4/tcp.c:3768
sock_common_setsockopt+0xb0/0xcc net/core/sock.c:3735
smc_setsockopt+0x204/0x10fc net/smc/af_smc.c:3072
do_sock_setsockopt+0x2a0/0x4e0 net/socket.c:2324
__sys_setsockopt+0x128/0x1a8 net/socket.c:2347
__do_sys_setsockopt net/socket.c:2356 [inline]
__se_sys_setsockopt net/socket.c:2353 [inline]
__arm64_sys_setsockopt+0xb8/0xd4 net/socket.c:2353
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
other info that might help us debug this:
Chain exists of:
rtnl_mutex --> sk_lock-AF_INET --> &smc->clcsock_release_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&smc->clcsock_release_lock);
lock(sk_lock-AF_INET);
lock(&smc->clcsock_release_lock);
lock(rtnl_mutex);
*** DEADLOCK ***
1 lock held by syz-executor272/6388:
#0: ffff0000dc408a50 (&smc->clcsock_release_lock){+.+.}-{3:3}, at: smc_setsockopt+0x178/0x10fc net/smc/af_smc.c:3064
stack backtrace:
CPU: 1 UID: 0 PID: 6388 Comm: syz-executor272 Not tainted 6.11.0-rc5-syzkaller-gdf54f4a16f82 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call trace:
dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:317
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:324
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:119
dump_stack+0x1c/0x28 lib/dump_stack.c:128
print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2059
check_noncircular+0x310/0x404 kernel/locking/lockdep.c:2186
check_prev_add kernel/locking/lockdep.c:3133 [inline]
check_prevs_add kernel/locking/lockdep.c:3252 [inline]
validate_chain kernel/locking/lockdep.c:3868 [inline]
__lock_acquire+0x33d8/0x779c kernel/locking/lockdep.c:5142
lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5759
__mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608
__mutex_lock kernel/locking/mutex.c:752 [inline]
mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804
rtnl_lock+0x20/0x2c net/core/rtnetlink.c:79
do_ip_setsockopt+0xe8c/0x346c net/ipv4/ip_sockglue.c:1077
ip_setsockopt+0x80/0x128 net/ipv4/ip_sockglue.c:1417
tcp_setsockopt+0xcc/0xe8 net/ipv4/tcp.c:3768
sock_common_setsockopt+0xb0/0xcc net/core/sock.c:3735
smc_setsockopt+0x204/0x10fc net/smc/af_smc.c:3072
do_sock_setsockopt+0x2a0/0x4e0 net/socket.c:2324
__sys_setsockopt+0x128/0x1a8 net/socket.c:2347
__do_sys_setsockopt net/socket.c:2356 [inline]
__se_sys_setsockopt net/socket.c:2353 [inline]
__arm64_sys_setsockopt+0xb8/0xd4 net/socket.c:2353
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
---
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#syz test: git://repo/address.git branch-or-commit-hash
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