netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [syzbot] [net?] possible deadlock in rtnl_lock (8)
@ 2024-08-19  3:49 syzbot
  2024-09-08  8:12 ` syzbot
  0 siblings, 1 reply; 7+ messages in thread
From: syzbot @ 2024-08-19  3:49 UTC (permalink / raw)
  To: davem, edumazet, kuba, linux-kernel, netdev, pabeni,
	syzkaller-bugs

Hello,

syzbot found the following issue on:

HEAD commit:    1fb918967b56 Merge tag 'for-6.11-rc3-tag' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=129dd7d9980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=804764788c03071f
dashboard link: https://syzkaller.appspot.com/bug?extid=51cf7cc5f9ffc1006ef2
compiler:       aarch64-linux-gnu-gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/384ffdcca292/non_bootable_disk-1fb91896.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7b8fac7b5b8b/vmlinux-1fb91896.xz
kernel image: https://storage.googleapis.com/syzbot-assets/676950a147e6/Image-1fb91896.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+51cf7cc5f9ffc1006ef2@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc3-syzkaller-00066-g1fb918967b56 #0 Not tainted
------------------------------------------------------
syz.0.5481/17612 is trying to acquire lock:
ffff8000880033a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x1c/0x28 net/core/rtnetlink.c:79

but task is already holding lock:
ffff000010332b50 (&smc->clcsock_release_lock){+.+.}-{3:3}, at: smc_setsockopt+0xd8/0xcec 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 kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x134/0x840 kernel/locking/mutex.c:752
       mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:804
       smc_switch_to_fallback+0x34/0x80c net/smc/af_smc.c:902
       smc_sendmsg+0xe4/0x8f8 net/smc/af_smc.c:2779
       sock_sendmsg_nosec net/socket.c:730 [inline]
       __sock_sendmsg+0xc8/0x168 net/socket.c:745
       __sys_sendto+0x1a8/0x254 net/socket.c:2204
       __do_sys_sendto net/socket.c:2216 [inline]
       __se_sys_sendto net/socket.c:2212 [inline]
       __arm64_sys_sendto+0xc0/0x134 net/socket.c:2212
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49
       el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x50/0x180 arch/arm64/kernel/entry-common.c:712
       el0t_64_sync_handler+0x100/0x12c 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+0x38/0xe8 net/core/sock.c:3543
       lock_sock include/net/sock.h:1607 [inline]
       sockopt_lock_sock net/core/sock.c:1061 [inline]
       sockopt_lock_sock+0x58/0x74 net/core/sock.c:1052
       do_ip_setsockopt+0xe0/0x2358 net/ipv4/ip_sockglue.c:1078
       ip_setsockopt+0x34/0x9c net/ipv4/ip_sockglue.c:1417
       raw_setsockopt+0x7c/0x2e0 net/ipv4/raw.c:845
       sock_common_setsockopt+0x70/0xe0 net/core/sock.c:3735
       do_sock_setsockopt+0x17c/0x354 net/socket.c:2324
       __sys_setsockopt+0xdc/0x178 net/socket.c:2347
       __do_sys_setsockopt net/socket.c:2356 [inline]
       __se_sys_setsockopt net/socket.c:2353 [inline]
       __arm64_sys_setsockopt+0xa4/0x100 net/socket.c:2353
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49
       el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x50/0x180 arch/arm64/kernel/entry-common.c:712
       el0t_64_sync_handler+0x100/0x12c 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+0x2aa4/0x6340 kernel/locking/lockdep.c:5142
       lock_acquire kernel/locking/lockdep.c:5759 [inline]
       lock_acquire+0x48c/0x7a4 kernel/locking/lockdep.c:5724
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x134/0x840 kernel/locking/mutex.c:752
       mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:804
       rtnl_lock+0x1c/0x28 net/core/rtnetlink.c:79
       do_ipv6_setsockopt+0x1a04/0x3814 net/ipv6/ipv6_sockglue.c:566
       ipv6_setsockopt+0xc8/0x140 net/ipv6/ipv6_sockglue.c:993
       tcp_setsockopt+0x90/0xcc net/ipv4/tcp.c:3768
       sock_common_setsockopt+0x70/0xe0 net/core/sock.c:3735
       smc_setsockopt+0x150/0xcec net/smc/af_smc.c:3072
       do_sock_setsockopt+0x17c/0x354 net/socket.c:2324
       __sys_setsockopt+0xdc/0x178 net/socket.c:2347
       __do_sys_setsockopt net/socket.c:2356 [inline]
       __se_sys_setsockopt net/socket.c:2353 [inline]
       __arm64_sys_setsockopt+0xa4/0x100 net/socket.c:2353
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49
       el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x50/0x180 arch/arm64/kernel/entry-common.c:712
       el0t_64_sync_handler+0x100/0x12c 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.0.5481/17612:
 #0: ffff000010332b50 (&smc->clcsock_release_lock){+.+.}-{3:3}, at: smc_setsockopt+0xd8/0xcec net/smc/af_smc.c:3064

stack backtrace:
CPU: 1 UID: 0 PID: 17612 Comm: syz.0.5481 Not tainted 6.11.0-rc3-syzkaller-00066-g1fb918967b56 #0
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace+0x9c/0x11c arch/arm64/kernel/stacktrace.c:317
 show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:324
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0xa4/0xf4 lib/dump_stack.c:119
 dump_stack+0x1c/0x28 lib/dump_stack.c:128
 print_circular_bug+0x420/0x6f8 kernel/locking/lockdep.c:2059
 check_noncircular+0x2dc/0x364 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+0x2aa4/0x6340 kernel/locking/lockdep.c:5142
 lock_acquire kernel/locking/lockdep.c:5759 [inline]
 lock_acquire+0x48c/0x7a4 kernel/locking/lockdep.c:5724
 __mutex_lock_common kernel/locking/mutex.c:608 [inline]
 __mutex_lock+0x134/0x840 kernel/locking/mutex.c:752
 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:804
 rtnl_lock+0x1c/0x28 net/core/rtnetlink.c:79
 do_ipv6_setsockopt+0x1a04/0x3814 net/ipv6/ipv6_sockglue.c:566
 ipv6_setsockopt+0xc8/0x140 net/ipv6/ipv6_sockglue.c:993
 tcp_setsockopt+0x90/0xcc net/ipv4/tcp.c:3768
 sock_common_setsockopt+0x70/0xe0 net/core/sock.c:3735
 smc_setsockopt+0x150/0xcec net/smc/af_smc.c:3072
 do_sock_setsockopt+0x17c/0x354 net/socket.c:2324
 __sys_setsockopt+0xdc/0x178 net/socket.c:2347
 __do_sys_setsockopt net/socket.c:2356 [inline]
 __se_sys_setsockopt net/socket.c:2353 [inline]
 __arm64_sys_setsockopt+0xa4/0x100 net/socket.c:2353
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49
 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x50/0x180 arch/arm64/kernel/entry-common.c:712
 el0t_64_sync_handler+0x100/0x12c arch/arm64/kernel/entry-common.c:730
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [syzbot] [net?] possible deadlock in rtnl_lock (8)
  2024-08-19  3:49 [syzbot] [net?] possible deadlock in rtnl_lock (8) syzbot
@ 2024-09-08  8:12 ` syzbot
  2024-09-09  8:02   ` Eric Dumazet
  0 siblings, 1 reply; 7+ messages in thread
From: syzbot @ 2024-09-08  8:12 UTC (permalink / raw)
  To: davem, edumazet, kuba, linux-kernel, netdev, pabeni,
	syzkaller-bugs

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@syzkaller.appspotmail.com

======================================================
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


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [syzbot] [net?] possible deadlock in rtnl_lock (8)
  2024-09-08  8:12 ` syzbot
@ 2024-09-09  8:02   ` Eric Dumazet
  2024-09-09 11:44     ` Wenjia Zhang
  0 siblings, 1 reply; 7+ messages in thread
From: Eric Dumazet @ 2024-09-09  8:02 UTC (permalink / raw)
  To: syzbot, D. Wythe, Wenjia Zhang, Dust Li
  Cc: davem, kuba, linux-kernel, netdev, pabeni, syzkaller-bugs

On Sun, Sep 8, 2024 at 10:12 AM syzbot
<syzbot+51cf7cc5f9ffc1006ef2@syzkaller.appspotmail.com> wrote:
>
> 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@syzkaller.appspotmail.com
>
> ======================================================
> 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
>
>
> ---
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.

Please SMC folks, can you take a look ?

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [syzbot] [net?] possible deadlock in rtnl_lock (8)
  2024-09-09  8:02   ` Eric Dumazet
@ 2024-09-09 11:44     ` Wenjia Zhang
  2024-09-10  5:55       ` D. Wythe
  0 siblings, 1 reply; 7+ messages in thread
From: Wenjia Zhang @ 2024-09-09 11:44 UTC (permalink / raw)
  To: Eric Dumazet, syzbot, D. Wythe, Dust Li
  Cc: davem, kuba, linux-kernel, netdev, pabeni, syzkaller-bugs



On 09.09.24 10:02, Eric Dumazet wrote:
> On Sun, Sep 8, 2024 at 10:12 AM syzbot
> <syzbot+51cf7cc5f9ffc1006ef2@syzkaller.appspotmail.com> wrote:
>>
>> 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@syzkaller.appspotmail.com
>>
>> ======================================================
>> 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
>>
>>
>> ---
>> If you want syzbot to run the reproducer, reply with:
>> #syz test: git://repo/address.git branch-or-commit-hash
>> If you attach or paste a git patch, syzbot will apply it before testing.
> 
> Please SMC folks, can you take a look ?

Hi Eric,

Thank you for the reminder! We'll look into it ASAP!

Thanks,
Wenjia

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [syzbot] [net?] possible deadlock in rtnl_lock (8)
  2024-09-09 11:44     ` Wenjia Zhang
@ 2024-09-10  5:55       ` D. Wythe
  2024-09-10  6:36         ` Eric Dumazet
  0 siblings, 1 reply; 7+ messages in thread
From: D. Wythe @ 2024-09-10  5:55 UTC (permalink / raw)
  To: Wenjia Zhang, Eric Dumazet, syzbot, Dust Li
  Cc: davem, kuba, linux-kernel, netdev, pabeni, syzkaller-bugs



On 9/9/24 7:44 PM, Wenjia Zhang wrote:
>
>
> On 09.09.24 10:02, Eric Dumazet wrote:
>> On Sun, Sep 8, 2024 at 10:12 AM syzbot
>> <syzbot+51cf7cc5f9ffc1006ef2@syzkaller.appspotmail.com> wrote:
>>>
>>> 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@syzkaller.appspotmail.com
>>>
>>> ======================================================
>>> 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.
>>>

I have noticed this issue for a while, but I question the possibility of 
it. If I understand correctly, a deadlock issue following is reported here:

#2
lock_sock_smc
{
     clcsock_release_lock            --- deadlock
     {

     }
}

#1
rtnl_mutex
{
     lock_sock_smc
     {

     }
}

#0
clcsock_release_lock
{
     rtnl_mutex                      --deadlock
     {

     }
}

This is of course a deadlock, but #1 is suspicious.

How would this happen to a smc sock?

#1 ->
        lock_sock_nested+0x38/0xe8 net/core/sock.c:3543
        lock_sock include/net/sock.h:1607 [inline]
        sockopt_lock_sock net/core/sock.c:1061 [inline]
        sockopt_lock_sock+0x58/0x74 net/core/sock.c:1052
        do_ip_setsockopt+0xe0/0x2358 net/ipv4/ip_sockglue.c:1078
        ip_setsockopt+0x34/0x9c net/ipv4/ip_sockglue.c:1417
        raw_setsockopt+0x7c/0x2e0 net/ipv4/raw.c:845
        sock_common_setsockopt+0x70/0xe0 net/core/sock.c:3735
        do_sock_setsockopt+0x17c/0x354 net/socket.c:2324

As a comparison, the correct calling chain should be:

        sock_common_setsockopt+0x70/0xe0 net/core/sock.c:3735
        smc_setsockopt+0x150/0xcec net/smc/af_smc.c:3072
        do_sock_setsockopt+0x17c/0x354 net/socket.c:2324


That's to say,  any setting on SOL_IP options of smc_sock will
go with smc_setsockopt, which will try lock clcsock_release_lock at first.

Anyway, if anyone can explain #1, then we can see how to solve this problem,
otherwise I think this problem doesn't exist. (Just my opinion)

Best wishes,
D. Wythe





^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [syzbot] [net?] possible deadlock in rtnl_lock (8)
  2024-09-10  5:55       ` D. Wythe
@ 2024-09-10  6:36         ` Eric Dumazet
  2024-09-10  6:58           ` D. Wythe
  0 siblings, 1 reply; 7+ messages in thread
From: Eric Dumazet @ 2024-09-10  6:36 UTC (permalink / raw)
  To: D. Wythe
  Cc: Wenjia Zhang, syzbot, Dust Li, davem, kuba, linux-kernel, netdev,
	pabeni, syzkaller-bugs

On Tue, Sep 10, 2024 at 7:55 AM D. Wythe <alibuda@linux.alibaba.com> wrote:
>
>
>
> On 9/9/24 7:44 PM, Wenjia Zhang wrote:
> >
> >
> > On 09.09.24 10:02, Eric Dumazet wrote:
> >> On Sun, Sep 8, 2024 at 10:12 AM syzbot
> >> <syzbot+51cf7cc5f9ffc1006ef2@syzkaller.appspotmail.com> wrote:
> >>>
> >>> 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@syzkaller.appspotmail.com
> >>>
> >>> ======================================================
> >>> 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.
> >>>
>
> I have noticed this issue for a while, but I question the possibility of
> it. If I understand correctly, a deadlock issue following is reported here:
>
> #2
> lock_sock_smc
> {
>      clcsock_release_lock            --- deadlock
>      {
>
>      }
> }
>
> #1
> rtnl_mutex
> {
>      lock_sock_smc
>      {
>
>      }
> }
>
> #0
> clcsock_release_lock
> {
>      rtnl_mutex                      --deadlock
>      {
>
>      }
> }
>
> This is of course a deadlock, but #1 is suspicious.
>
> How would this happen to a smc sock?
>
> #1 ->
>         lock_sock_nested+0x38/0xe8 net/core/sock.c:3543
>         lock_sock include/net/sock.h:1607 [inline]
>         sockopt_lock_sock net/core/sock.c:1061 [inline]
>         sockopt_lock_sock+0x58/0x74 net/core/sock.c:1052
>         do_ip_setsockopt+0xe0/0x2358 net/ipv4/ip_sockglue.c:1078
>         ip_setsockopt+0x34/0x9c net/ipv4/ip_sockglue.c:1417
>         raw_setsockopt+0x7c/0x2e0 net/ipv4/raw.c:845
>         sock_common_setsockopt+0x70/0xe0 net/core/sock.c:3735
>         do_sock_setsockopt+0x17c/0x354 net/socket.c:2324
>
> As a comparison, the correct calling chain should be:
>
>         sock_common_setsockopt+0x70/0xe0 net/core/sock.c:3735
>         smc_setsockopt+0x150/0xcec net/smc/af_smc.c:3072
>         do_sock_setsockopt+0x17c/0x354 net/socket.c:2324
>
>
> That's to say,  any setting on SOL_IP options of smc_sock will
> go with smc_setsockopt, which will try lock clcsock_release_lock at first.
>
> Anyway, if anyone can explain #1, then we can see how to solve this problem,
> otherwise I think this problem doesn't exist. (Just my opinion)

Then SMC lacks some lockdep annotations.

Please take a look at sock_lock_init_class_and_name() callers.

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [syzbot] [net?] possible deadlock in rtnl_lock (8)
  2024-09-10  6:36         ` Eric Dumazet
@ 2024-09-10  6:58           ` D. Wythe
  0 siblings, 0 replies; 7+ messages in thread
From: D. Wythe @ 2024-09-10  6:58 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Wenjia Zhang, syzbot, Dust Li, davem, kuba, linux-kernel, netdev,
	pabeni, syzkaller-bugs



On 9/10/24 2:36 PM, Eric Dumazet wrote:
> On Tue, Sep 10, 2024 at 7:55 AM D. Wythe <alibuda@linux.alibaba.com> wrote:
>>
>>
>> On 9/9/24 7:44 PM, Wenjia Zhang wrote:
>>>
>>> On 09.09.24 10:02, Eric Dumazet wrote:
>>>> On Sun, Sep 8, 2024 at 10:12 AM syzbot
>>>> <syzbot+51cf7cc5f9ffc1006ef2@syzkaller.appspotmail.com> wrote:
>>>>> 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@syzkaller.appspotmail.com
>>>>>
>>>>> ======================================================
>>>>> 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.
>>>>>
>> I have noticed this issue for a while, but I question the possibility of
>> it. If I understand correctly, a deadlock issue following is reported here:
>>
>> #2
>> lock_sock_smc
>> {
>>       clcsock_release_lock            --- deadlock
>>       {
>>
>>       }
>> }
>>
>> #1
>> rtnl_mutex
>> {
>>       lock_sock_smc
>>       {
>>
>>       }
>> }
>>
>> #0
>> clcsock_release_lock
>> {
>>       rtnl_mutex                      --deadlock
>>       {
>>
>>       }
>> }
>>
>> This is of course a deadlock, but #1 is suspicious.
>>
>> How would this happen to a smc sock?
>>
>> #1 ->
>>          lock_sock_nested+0x38/0xe8 net/core/sock.c:3543
>>          lock_sock include/net/sock.h:1607 [inline]
>>          sockopt_lock_sock net/core/sock.c:1061 [inline]
>>          sockopt_lock_sock+0x58/0x74 net/core/sock.c:1052
>>          do_ip_setsockopt+0xe0/0x2358 net/ipv4/ip_sockglue.c:1078
>>          ip_setsockopt+0x34/0x9c net/ipv4/ip_sockglue.c:1417
>>          raw_setsockopt+0x7c/0x2e0 net/ipv4/raw.c:845
>>          sock_common_setsockopt+0x70/0xe0 net/core/sock.c:3735
>>          do_sock_setsockopt+0x17c/0x354 net/socket.c:2324
>>
>> As a comparison, the correct calling chain should be:
>>
>>          sock_common_setsockopt+0x70/0xe0 net/core/sock.c:3735
>>          smc_setsockopt+0x150/0xcec net/smc/af_smc.c:3072
>>          do_sock_setsockopt+0x17c/0x354 net/socket.c:2324
>>
>>
>> That's to say,  any setting on SOL_IP options of smc_sock will
>> go with smc_setsockopt, which will try lock clcsock_release_lock at first.
>>
>> Anyway, if anyone can explain #1, then we can see how to solve this problem,
>> otherwise I think this problem doesn't exist. (Just my opinion)
> Then SMC lacks some lockdep annotations.
>
> Please take a look at sock_lock_init_class_and_name() callers.

It seems so, which also explains why it wasn't reported with AF_SMC sock.
I'll try to fix it ASAP.

D. Wythe


^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2024-09-10  6:58 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-08-19  3:49 [syzbot] [net?] possible deadlock in rtnl_lock (8) syzbot
2024-09-08  8:12 ` syzbot
2024-09-09  8:02   ` Eric Dumazet
2024-09-09 11:44     ` Wenjia Zhang
2024-09-10  5:55       ` D. Wythe
2024-09-10  6:36         ` Eric Dumazet
2024-09-10  6:58           ` D. Wythe

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).