* [syzbot] [rdma?] [s390?] [net?] KASAN: null-ptr-deref Read in smc_tcp_syn_recv_sock
@ 2025-03-31 20:23 syzbot
2025-06-30 0:27 ` Hillf Danton
0 siblings, 1 reply; 3+ messages in thread
From: syzbot @ 2025-03-31 20:23 UTC (permalink / raw)
To: agordeev, alibuda, davem, edumazet, guwen, horms, jaka, kuba,
linux-kernel, linux-rdma, linux-s390, netdev, pabeni,
syzkaller-bugs, tonylu, wenjia
Hello,
syzbot found the following issue on:
HEAD commit: 850925a8133c Merge tag '9p-for-6.12-rc5' of https://github..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1227aa87980000
kernel config: https://syzkaller.appspot.com/x/.config?x=17c0d505695d6b0
dashboard link: https://syzkaller.appspot.com/bug?extid=827ae2bfb3a3529333e9
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15489230580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6d8177e17058/disk-850925a8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5d88252f39ff/vmlinux-850925a8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7a675a61b90d/bzImage-850925a8.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+827ae2bfb3a3529333e9@syzkaller.appspotmail.com
TCP: request_sock_TCP: Possible SYN flooding on port [::]:20002. Sending cookies.
TCP: request_sock_TCP: Possible SYN flooding on port [::]:20002. Sending cookies.
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: null-ptr-deref in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
BUG: KASAN: null-ptr-deref in smc_tcp_syn_recv_sock+0xa7/0x4b0 net/smc/af_smc.c:131
Read of size 4 at addr 00000000000009d4 by task syz.4.10809/28966
CPU: 1 UID: 0 PID: 28966 Comm: syz.4.10809 Not tainted 6.12.0-rc4-syzkaller-00261-g850925a8133c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
kasan_report+0xd9/0x110 mm/kasan/report.c:601
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
instrument_atomic_read include/linux/instrumented.h:68 [inline]
atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
smc_tcp_syn_recv_sock+0xa7/0x4b0 net/smc/af_smc.c:131
tcp_get_cookie_sock+0xd5/0x790 net/ipv4/syncookies.c:204
cookie_v4_check+0xcf8/0x1d40 net/ipv4/syncookies.c:485
tcp_v4_cookie_check net/ipv4/tcp_ipv4.c:1864 [inline]
tcp_v4_do_rcv+0x98e/0xa90 net/ipv4/tcp_ipv4.c:1923
tcp_v4_rcv+0x3cd2/0x4390 net/ipv4/tcp_ipv4.c:2340
ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x316/0x570 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:314 [inline]
NF_HOOK include/linux/netfilter.h:308 [inline]
ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:460 [inline]
ip_rcv_finish net/ipv4/ip_input.c:449 [inline]
NF_HOOK include/linux/netfilter.h:314 [inline]
NF_HOOK include/linux/netfilter.h:308 [inline]
ip_rcv+0x2c3/0x5d0 net/ipv4/ip_input.c:569
__netif_receive_skb_one_core+0x199/0x1e0 net/core/dev.c:5666
__netif_receive_skb+0x1d/0x160 net/core/dev.c:5779
process_backlog+0x443/0x15f0 net/core/dev.c:6111
__napi_poll.constprop.0+0xba/0x550 net/core/dev.c:6775
napi_poll net/core/dev.c:6844 [inline]
net_rx_action+0xa92/0x1010 net/core/dev.c:6966
handle_softirqs+0x216/0x8f0 kernel/softirq.c:554
do_softirq kernel/softirq.c:455 [inline]
do_softirq+0xb2/0xf0 kernel/softirq.c:442
</IRQ>
<TASK>
__local_bh_enable_ip+0x100/0x120 kernel/softirq.c:382
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline]
__dev_queue_xmit+0x887/0x4350 net/core/dev.c:4455
dev_queue_xmit include/linux/netdevice.h:3094 [inline]
neigh_hh_output include/net/neighbour.h:526 [inline]
neigh_output include/net/neighbour.h:540 [inline]
ip_finish_output2+0x16d7/0x2530 net/ipv4/ip_output.c:236
__ip_finish_output net/ipv4/ip_output.c:314 [inline]
__ip_finish_output+0x49e/0x950 net/ipv4/ip_output.c:296
ip_finish_output+0x31/0x310 net/ipv4/ip_output.c:324
NF_HOOK_COND include/linux/netfilter.h:303 [inline]
ip_output+0x13b/0x2a0 net/ipv4/ip_output.c:434
dst_output include/net/dst.h:450 [inline]
ip_local_out+0x33e/0x4a0 net/ipv4/ip_output.c:130
__ip_queue_xmit+0x747/0x1940 net/ipv4/ip_output.c:536
__tcp_transmit_skb+0x2a4c/0x3dc0 net/ipv4/tcp_output.c:1466
__tcp_send_ack.part.0+0x390/0x720 net/ipv4/tcp_output.c:4268
__tcp_send_ack net/ipv4/tcp_output.c:4274 [inline]
tcp_send_ack+0x82/0xa0 net/ipv4/tcp_output.c:4274
tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6576 [inline]
tcp_rcv_state_process+0x4332/0x4f30 net/ipv4/tcp_input.c:6770
tcp_v4_do_rcv+0x1ad/0xa90 net/ipv4/tcp_ipv4.c:1938
sk_backlog_rcv include/net/sock.h:1115 [inline]
__release_sock+0x31b/0x400 net/core/sock.c:3072
release_sock+0x5a/0x220 net/core/sock.c:3626
mptcp_connect+0xc14/0xee0 net/mptcp/protocol.c:3800
__inet_stream_connect+0x3ca/0x1020 net/ipv4/af_inet.c:679
inet_stream_connect+0x57/0xa0 net/ipv4/af_inet.c:750
__sys_connect_file+0x150/0x190 net/socket.c:2071
__sys_connect+0x147/0x180 net/socket.c:2088
__do_sys_connect net/socket.c:2098 [inline]
__se_sys_connect net/socket.c:2095 [inline]
__x64_sys_connect+0x72/0xb0 net/socket.c:2095
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f68acb7e719
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f68ada08038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f68acd35f80 RCX: 00007f68acb7e719
RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000004
RBP: 00007f68acbf132e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f68acd35f80 R15: 00007ffdea14cb48
</TASK>
==================================================================
Oops: general protection fault, probably for non-canonical address 0xdffffc000000013a: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x00000000000009d0-0x00000000000009d7]
CPU: 1 UID: 0 PID: 28966 Comm: syz.4.10809 Tainted: G B 6.12.0-rc4-syzkaller-00261-g850925a8133c #0
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
RIP: 0010:smc_tcp_syn_recv_sock+0xb8/0x4b0 net/smc/af_smc.c:131
Code: ad d4 09 00 00 be 04 00 00 00 44 8b bb 1c 04 00 00 4c 89 ef e8 69 94 2e f7 4c 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <0f> b6 14 02 4c 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 34
RSP: 0018:ffffc90000a18668 EFLAGS: 00010217
RAX: dffffc0000000000 RBX: ffff88805b9cb600 RCX: ffffffff814e856f
RDX: 000000000000013a RSI: ffffffff81ee031e RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 6e696c6261736944 R12: ffff88807df5bd00
R13: 00000000000009d4 R14: ffffc90000a186e8 R15: 0000000000000000
FS: 00007f68ada086c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f68ad9e7d58 CR3: 000000005e3fa000 CR4: 0000000000350ef0
Call Trace:
<IRQ>
tcp_get_cookie_sock+0xd5/0x790 net/ipv4/syncookies.c:204
cookie_v4_check+0xcf8/0x1d40 net/ipv4/syncookies.c:485
tcp_v4_cookie_check net/ipv4/tcp_ipv4.c:1864 [inline]
tcp_v4_do_rcv+0x98e/0xa90 net/ipv4/tcp_ipv4.c:1923
tcp_v4_rcv+0x3cd2/0x4390 net/ipv4/tcp_ipv4.c:2340
ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x316/0x570 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:314 [inline]
NF_HOOK include/linux/netfilter.h:308 [inline]
ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:460 [inline]
ip_rcv_finish net/ipv4/ip_input.c:449 [inline]
NF_HOOK include/linux/netfilter.h:314 [inline]
NF_HOOK include/linux/netfilter.h:308 [inline]
ip_rcv+0x2c3/0x5d0 net/ipv4/ip_input.c:569
__netif_receive_skb_one_core+0x199/0x1e0 net/core/dev.c:5666
__netif_receive_skb+0x1d/0x160 net/core/dev.c:5779
process_backlog+0x443/0x15f0 net/core/dev.c:6111
__napi_poll.constprop.0+0xba/0x550 net/core/dev.c:6775
napi_poll net/core/dev.c:6844 [inline]
net_rx_action+0xa92/0x1010 net/core/dev.c:6966
handle_softirqs+0x216/0x8f0 kernel/softirq.c:554
do_softirq kernel/softirq.c:455 [inline]
do_softirq+0xb2/0xf0 kernel/softirq.c:442
</IRQ>
<TASK>
__local_bh_enable_ip+0x100/0x120 kernel/softirq.c:382
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline]
__dev_queue_xmit+0x887/0x4350 net/core/dev.c:4455
dev_queue_xmit include/linux/netdevice.h:3094 [inline]
neigh_hh_output include/net/neighbour.h:526 [inline]
neigh_output include/net/neighbour.h:540 [inline]
ip_finish_output2+0x16d7/0x2530 net/ipv4/ip_output.c:236
__ip_finish_output net/ipv4/ip_output.c:314 [inline]
__ip_finish_output+0x49e/0x950 net/ipv4/ip_output.c:296
ip_finish_output+0x31/0x310 net/ipv4/ip_output.c:324
NF_HOOK_COND include/linux/netfilter.h:303 [inline]
ip_output+0x13b/0x2a0 net/ipv4/ip_output.c:434
dst_output include/net/dst.h:450 [inline]
ip_local_out+0x33e/0x4a0 net/ipv4/ip_output.c:130
__ip_queue_xmit+0x747/0x1940 net/ipv4/ip_output.c:536
__tcp_transmit_skb+0x2a4c/0x3dc0 net/ipv4/tcp_output.c:1466
__tcp_send_ack.part.0+0x390/0x720 net/ipv4/tcp_output.c:4268
__tcp_send_ack net/ipv4/tcp_output.c:4274 [inline]
tcp_send_ack+0x82/0xa0 net/ipv4/tcp_output.c:4274
tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6576 [inline]
tcp_rcv_state_process+0x4332/0x4f30 net/ipv4/tcp_input.c:6770
tcp_v4_do_rcv+0x1ad/0xa90 net/ipv4/tcp_ipv4.c:1938
sk_backlog_rcv include/net/sock.h:1115 [inline]
__release_sock+0x31b/0x400 net/core/sock.c:3072
release_sock+0x5a/0x220 net/core/sock.c:3626
mptcp_connect+0xc14/0xee0 net/mptcp/protocol.c:3800
__inet_stream_connect+0x3ca/0x1020 net/ipv4/af_inet.c:679
inet_stream_connect+0x57/0xa0 net/ipv4/af_inet.c:750
__sys_connect_file+0x150/0x190 net/socket.c:2071
__sys_connect+0x147/0x180 net/socket.c:2088
__do_sys_connect net/socket.c:2098 [inline]
__se_sys_connect net/socket.c:2095 [inline]
__x64_sys_connect+0x72/0xb0 net/socket.c:2095
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f68acb7e719
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f68ada08038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f68acd35f80 RCX: 00007f68acb7e719
RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000004
RBP: 00007f68acbf132e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f68acd35f80 R15: 00007ffdea14cb48
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
RIP: 0010:smc_tcp_syn_recv_sock+0xb8/0x4b0 net/smc/af_smc.c:131
Code: ad d4 09 00 00 be 04 00 00 00 44 8b bb 1c 04 00 00 4c 89 ef e8 69 94 2e f7 4c 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <0f> b6 14 02 4c 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 34
RSP: 0018:ffffc90000a18668 EFLAGS: 00010217
RAX: dffffc0000000000 RBX: ffff88805b9cb600 RCX: ffffffff814e856f
RDX: 000000000000013a RSI: ffffffff81ee031e RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 6e696c6261736944 R12: ffff88807df5bd00
R13: 00000000000009d4 R14: ffffc90000a186e8 R15: 0000000000000000
FS: 00007f68ada086c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f68ad9e7d58 CR3: 000000005e3fa000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess), 2 bytes skipped:
0: 09 00 or %eax,(%rax)
2: 00 be 04 00 00 00 add %bh,0x4(%rsi)
8: 44 8b bb 1c 04 00 00 mov 0x41c(%rbx),%r15d
f: 4c 89 ef mov %r13,%rdi
12: e8 69 94 2e f7 call 0xf72e9480
17: 4c 89 ea mov %r13,%rdx
1a: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
21: fc ff df
24: 48 c1 ea 03 shr $0x3,%rdx
* 28: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx <-- trapping instruction
2c: 4c 89 e8 mov %r13,%rax
2f: 83 e0 07 and $0x7,%eax
32: 83 c0 03 add $0x3,%eax
35: 38 d0 cmp %dl,%al
37: 7c 08 jl 0x41
39: 84 d2 test %dl,%dl
3b: 0f .byte 0xf
3c: 85 .byte 0x85
3d: 34 .byte 0x34
---
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:
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If the report is already addressed, let syzbot know by replying with:
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If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [syzbot] [rdma?] [s390?] [net?] KASAN: null-ptr-deref Read in smc_tcp_syn_recv_sock
[not found] <20250405100756.1027477-1-richard120310@gmail.com>
@ 2025-04-05 12:04 ` syzbot
0 siblings, 0 replies; 3+ messages in thread
From: syzbot @ 2025-04-05 12:04 UTC (permalink / raw)
To: linux-kernel, richard120310, syzkaller-bugs
Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
possible deadlock in smc_release
======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc4-syzkaller-00261-g850925a8133c-dirty #0 Not tainted
------------------------------------------------------
syz.1.6963/21920 is trying to acquire lock:
ffff888033c0b750 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: touch_work_lockdep_map kernel/workqueue.c:3895 [inline]
ffff888033c0b750 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4149 [inline]
ffff888033c0b750 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x46d/0xc30 kernel/workqueue.c:4181
but task is already holding lock:
ffff88805fe88dd8 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x378/0x5f0 net/smc/af_smc.c:338
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (sk_lock-AF_SMC/1){+.+.}-{0:0}:
lock_sock_nested+0x3a/0xf0 net/core/sock.c:3611
smc_listen_out+0x1fa/0x490 net/smc/af_smc.c:1907
smc_listen_out_connected net/smc/af_smc.c:1927 [inline]
smc_listen_work+0x571/0x50c0 net/smc/af_smc.c:2441
process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
kthread+0x2c4/0x3a0 kernel/kthread.c:389
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
-> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
touch_work_lockdep_map kernel/workqueue.c:3895 [inline]
start_flush_work kernel/workqueue.c:4149 [inline]
__flush_work+0x477/0xc30 kernel/workqueue.c:4181
__cancel_work_sync+0x10c/0x130 kernel/workqueue.c:4337
smc_clcsock_release+0x5f/0xe0 net/smc/smc_close.c:29
__smc_release+0x5c2/0x880 net/smc/af_smc.c:303
smc_close_non_accepted+0xda/0x200 net/smc/af_smc.c:1839
smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
smc_close_active+0xc3c/0x1070 net/smc/smc_close.c:225
__smc_release+0x634/0x880 net/smc/af_smc.c:279
smc_release+0x1fc/0x5f0 net/smc/af_smc.c:346
__sock_release+0xb3/0x270 net/socket.c:658
sock_close+0x1c/0x30 net/socket.c:1426
__fput+0x3f9/0xb60 fs/file_table.c:431
task_work_run+0x151/0x250 kernel/task_work.c:239
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sk_lock-AF_SMC/1);
lock((work_completion)(&new_smc->smc_listen_work));
lock(sk_lock-AF_SMC/1);
lock((work_completion)(&new_smc->smc_listen_work));
*** DEADLOCK ***
3 locks held by syz.1.6963/21920:
#0: ffff8880746ea008 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
#0: ffff8880746ea008 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release+0x86/0x270 net/socket.c:657
#1: ffff88805fe88dd8 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x378/0x5f0 net/smc/af_smc.c:338
#2: ffffffff8e1b8380 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#2: ffffffff8e1b8380 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#2: ffffffff8e1b8380 (rcu_read_lock){....}-{1:2}, at: start_flush_work kernel/workqueue.c:4123 [inline]
#2: ffffffff8e1b8380 (rcu_read_lock){....}-{1:2}, at: __flush_work+0x103/0xc30 kernel/workqueue.c:4181
stack backtrace:
CPU: 0 UID: 0 PID: 21920 Comm: syz.1.6963 Not tainted 6.12.0-rc4-syzkaller-00261-g850925a8133c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_circular_bug+0x41c/0x610 kernel/locking/lockdep.c:2074
check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2206
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
touch_work_lockdep_map kernel/workqueue.c:3895 [inline]
start_flush_work kernel/workqueue.c:4149 [inline]
__flush_work+0x477/0xc30 kernel/workqueue.c:4181
__cancel_work_sync+0x10c/0x130 kernel/workqueue.c:4337
smc_clcsock_release+0x5f/0xe0 net/smc/smc_close.c:29
__smc_release+0x5c2/0x880 net/smc/af_smc.c:303
smc_close_non_accepted+0xda/0x200 net/smc/af_smc.c:1839
smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
smc_close_active+0xc3c/0x1070 net/smc/smc_close.c:225
__smc_release+0x634/0x880 net/smc/af_smc.c:279
smc_release+0x1fc/0x5f0 net/smc/af_smc.c:346
__sock_release+0xb3/0x270 net/socket.c:658
sock_close+0x1c/0x30 net/socket.c:1426
__fput+0x3f9/0xb60 fs/file_table.c:431
task_work_run+0x151/0x250 kernel/task_work.c:239
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f851fb7e719
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f85208c6038 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f851fd35f80 RCX: 00007f851fb7e719
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000003
RBP: 00007f851fbf132e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f851fd35f80 R15: 00007ffea8200be8
</TASK>
Tested on:
commit: 850925a8 Merge tag '9p-for-6.12-rc5' of https://github..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=114cefb0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=17c0d505695d6b0
dashboard link: https://syzkaller.appspot.com/bug?extid=827ae2bfb3a3529333e9
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=155d294c580000
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [syzbot] [rdma?] [s390?] [net?] KASAN: null-ptr-deref Read in smc_tcp_syn_recv_sock
2025-03-31 20:23 syzbot
@ 2025-06-30 0:27 ` Hillf Danton
0 siblings, 0 replies; 3+ messages in thread
From: Hillf Danton @ 2025-06-30 0:27 UTC (permalink / raw)
To: syzbot; +Cc: linux-kernel, syzkaller-bugs
> Date: Mon, 31 Mar 2025 13:23:20 -0700
> syzbot found the following issue on:
>
> HEAD commit: 850925a8133c Merge tag '9p-for-6.12-rc5' of https://github..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1227aa87980000
> kernel config: https://syzkaller.appspot.com/x/.config?x=17c0d505695d6b0
> dashboard link: https://syzkaller.appspot.com/bug?extid=827ae2bfb3a3529333e9
> compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15489230580000
#syz test upstream master
--- x/net/smc/af_smc.c
+++ y/net/smc/af_smc.c
@@ -127,6 +127,8 @@ static struct sock *smc_tcp_syn_recv_soc
struct sock *child;
smc = smc_clcsock_user_data(sk);
+ if (!smc)
+ goto drop;
if (READ_ONCE(sk->sk_ack_backlog) + atomic_read(&smc->queued_smc_hs) >
sk->sk_max_ack_backlog)
--
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2025-06-30 0:27 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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[not found] <20250405100756.1027477-1-richard120310@gmail.com>
2025-04-05 12:04 ` [syzbot] [rdma?] [s390?] [net?] KASAN: null-ptr-deref Read in smc_tcp_syn_recv_sock syzbot
2025-03-31 20:23 syzbot
2025-06-30 0:27 ` Hillf Danton
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