net/smc/smc_inet.c | 13 ------------- 1 file changed, 13 deletions(-)
The syzbot report a crash:
Oops: general protection fault, probably for non-canonical address 0xfbd5a5d5a0000003: 0000 [#1] SMP KASAN NOPTI
KASAN: maybe wild-memory-access in range [0xdead4ead00000018-0xdead4ead0000001f]
CPU: 1 UID: 0 PID: 6949 Comm: syz.0.335 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:smc_diag_msg_common_fill net/smc/smc_diag.c:44 [inline]
RIP: 0010:__smc_diag_dump.constprop.0+0x3ca/0x2550 net/smc/smc_diag.c:89
Call Trace:
<TASK>
smc_diag_dump_proto+0x26d/0x420 net/smc/smc_diag.c:217
smc_diag_dump+0x27/0x90 net/smc/smc_diag.c:234
netlink_dump+0x539/0xd30 net/netlink/af_netlink.c:2327
__netlink_dump_start+0x6d6/0x990 net/netlink/af_netlink.c:2442
netlink_dump_start include/linux/netlink.h:341 [inline]
smc_diag_handler_dump+0x1f9/0x240 net/smc/smc_diag.c:251
__sock_diag_cmd net/core/sock_diag.c:249 [inline]
sock_diag_rcv_msg+0x438/0x790 net/core/sock_diag.c:285
netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg net/socket.c:729 [inline]
____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
__sys_sendmsg+0x16d/0x220 net/socket.c:2700
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
The process like this:
(CPU1) | (CPU2)
---------------------------------|-------------------------------
inet_create() |
// init clcsock to NULL |
sk = sk_alloc() |
|
// unexpectedly change clcsock |
inet_init_csk_locks() |
|
// add sk to hash table |
smc_inet_init_sock() |
smc_sk_init() |
smc_hash_sk() |
| // traverse the hash table
| smc_diag_dump_proto
| __smc_diag_dump()
| // visit wrong clcsock
| smc_diag_msg_common_fill()
// alloc clcsock |
smc_create_clcsk |
sock_create_kern |
With CONFIG_DEBUG_LOCK_ALLOC=y, the smc->clcsock is unexpectedly changed
in inet_init_csk_locks(). The INET_PROTOSW_ICSK flag is no need by smc,
just remove it.
After removing the INET_PROTOSW_ICSK flag, this patch alse revert
commit 6fd27ea183c2 ("net/smc: fix lacks of icsk_syn_mss with IPPROTO_SMC")
to avoid casting smc_sock to inet_connection_sock.
Reported-by: syzbot+f775be4458668f7d220e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f775be4458668f7d220e
Tested-by: syzbot+f775be4458668f7d220e@syzkaller.appspotmail.com
Fixes: d25a92ccae6b ("net/smc: Introduce IPPROTO_SMC")
Signed-off-by: Wang Liang <wangliang74@huawei.com>
---
v2: remove INET_PROTOSW_ICSK flag instead of init inet_connection_sock.
v1: https://lore.kernel.org/netdev/20250922121818.654011-1-wangliang74@huawei.com/
---
net/smc/smc_inet.c | 13 -------------
1 file changed, 13 deletions(-)
diff --git a/net/smc/smc_inet.c b/net/smc/smc_inet.c
index a944e7dcb8b9..a94084b4a498 100644
--- a/net/smc/smc_inet.c
+++ b/net/smc/smc_inet.c
@@ -56,7 +56,6 @@ static struct inet_protosw smc_inet_protosw = {
.protocol = IPPROTO_SMC,
.prot = &smc_inet_prot,
.ops = &smc_inet_stream_ops,
- .flags = INET_PROTOSW_ICSK,
};
#if IS_ENABLED(CONFIG_IPV6)
@@ -104,27 +103,15 @@ static struct inet_protosw smc_inet6_protosw = {
.protocol = IPPROTO_SMC,
.prot = &smc_inet6_prot,
.ops = &smc_inet6_stream_ops,
- .flags = INET_PROTOSW_ICSK,
};
#endif /* CONFIG_IPV6 */
-static unsigned int smc_sync_mss(struct sock *sk, u32 pmtu)
-{
- /* No need pass it through to clcsock, mss can always be set by
- * sock_create_kern or smc_setsockopt.
- */
- return 0;
-}
-
static int smc_inet_init_sock(struct sock *sk)
{
struct net *net = sock_net(sk);
/* init common smc sock */
smc_sk_init(net, sk, IPPROTO_SMC);
-
- inet_csk(sk)->icsk_sync_mss = smc_sync_mss;
-
/* create clcsock */
return smc_create_clcsk(net, sk, sk->sk_family);
}
--
2.34.1On Fri, Oct 17, 2025 at 10:48:27AM +0800, Wang Liang wrote:
> The syzbot report a crash:
>
> Oops: general protection fault, probably for non-canonical address 0xfbd5a5d5a0000003: 0000 [#1] SMP KASAN NOPTI
> KASAN: maybe wild-memory-access in range [0xdead4ead00000018-0xdead4ead0000001f]
> CPU: 1 UID: 0 PID: 6949 Comm: syz.0.335 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
> RIP: 0010:smc_diag_msg_common_fill net/smc/smc_diag.c:44 [inline]
> RIP: 0010:__smc_diag_dump.constprop.0+0x3ca/0x2550 net/smc/smc_diag.c:89
> Call Trace:
> <TASK>
> smc_diag_dump_proto+0x26d/0x420 net/smc/smc_diag.c:217
> smc_diag_dump+0x27/0x90 net/smc/smc_diag.c:234
> netlink_dump+0x539/0xd30 net/netlink/af_netlink.c:2327
> __netlink_dump_start+0x6d6/0x990 net/netlink/af_netlink.c:2442
> netlink_dump_start include/linux/netlink.h:341 [inline]
> smc_diag_handler_dump+0x1f9/0x240 net/smc/smc_diag.c:251
> __sock_diag_cmd net/core/sock_diag.c:249 [inline]
> sock_diag_rcv_msg+0x438/0x790 net/core/sock_diag.c:285
> netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
> netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
> netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
> netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
> sock_sendmsg_nosec net/socket.c:714 [inline]
> __sock_sendmsg net/socket.c:729 [inline]
> ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
> ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
> __sys_sendmsg+0x16d/0x220 net/socket.c:2700
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
> </TASK>
>
> The process like this:
>
> (CPU1) | (CPU2)
> ---------------------------------|-------------------------------
> inet_create() |
> // init clcsock to NULL |
> sk = sk_alloc() |
> |
> // unexpectedly change clcsock |
> inet_init_csk_locks() |
> |
> // add sk to hash table |
> smc_inet_init_sock() |
> smc_sk_init() |
> smc_hash_sk() |
> | // traverse the hash table
> | smc_diag_dump_proto
> | __smc_diag_dump()
> | // visit wrong clcsock
> | smc_diag_msg_common_fill()
> // alloc clcsock |
> smc_create_clcsk |
> sock_create_kern |
>
> With CONFIG_DEBUG_LOCK_ALLOC=y, the smc->clcsock is unexpectedly changed
> in inet_init_csk_locks(). The INET_PROTOSW_ICSK flag is no need by smc,
> just remove it.
>
> After removing the INET_PROTOSW_ICSK flag, this patch alse revert
> commit 6fd27ea183c2 ("net/smc: fix lacks of icsk_syn_mss with IPPROTO_SMC")
> to avoid casting smc_sock to inet_connection_sock.
>
> Reported-by: syzbot+f775be4458668f7d220e@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=f775be4458668f7d220e
> Tested-by: syzbot+f775be4458668f7d220e@syzkaller.appspotmail.com
> Fixes: d25a92ccae6b ("net/smc: Introduce IPPROTO_SMC")
> Signed-off-by: Wang Liang <wangliang74@huawei.com>
> ---
> v2: remove INET_PROTOSW_ICSK flag instead of init inet_connection_sock.
> v1: https://lore.kernel.org/netdev/20250922121818.654011-1-wangliang74@huawei.com/
> ---
LGTM.
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
From: Wang Liang <wangliang74@huawei.com>
Date: Fri, 17 Oct 2025 10:48:27 +0800
> The syzbot report a crash:
>
> Oops: general protection fault, probably for non-canonical address 0xfbd5a5d5a0000003: 0000 [#1] SMP KASAN NOPTI
> KASAN: maybe wild-memory-access in range [0xdead4ead00000018-0xdead4ead0000001f]
> CPU: 1 UID: 0 PID: 6949 Comm: syz.0.335 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
> RIP: 0010:smc_diag_msg_common_fill net/smc/smc_diag.c:44 [inline]
> RIP: 0010:__smc_diag_dump.constprop.0+0x3ca/0x2550 net/smc/smc_diag.c:89
> Call Trace:
> <TASK>
> smc_diag_dump_proto+0x26d/0x420 net/smc/smc_diag.c:217
> smc_diag_dump+0x27/0x90 net/smc/smc_diag.c:234
> netlink_dump+0x539/0xd30 net/netlink/af_netlink.c:2327
> __netlink_dump_start+0x6d6/0x990 net/netlink/af_netlink.c:2442
> netlink_dump_start include/linux/netlink.h:341 [inline]
> smc_diag_handler_dump+0x1f9/0x240 net/smc/smc_diag.c:251
> __sock_diag_cmd net/core/sock_diag.c:249 [inline]
> sock_diag_rcv_msg+0x438/0x790 net/core/sock_diag.c:285
> netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
> netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
> netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
> netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
> sock_sendmsg_nosec net/socket.c:714 [inline]
> __sock_sendmsg net/socket.c:729 [inline]
> ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
> ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
> __sys_sendmsg+0x16d/0x220 net/socket.c:2700
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
> </TASK>
>
> The process like this:
>
> (CPU1) | (CPU2)
> ---------------------------------|-------------------------------
> inet_create() |
> // init clcsock to NULL |
> sk = sk_alloc() |
> |
> // unexpectedly change clcsock |
> inet_init_csk_locks() |
> |
> // add sk to hash table |
> smc_inet_init_sock() |
> smc_sk_init() |
> smc_hash_sk() |
> | // traverse the hash table
> | smc_diag_dump_proto
> | __smc_diag_dump()
> | // visit wrong clcsock
> | smc_diag_msg_common_fill()
> // alloc clcsock |
> smc_create_clcsk |
> sock_create_kern |
>
> With CONFIG_DEBUG_LOCK_ALLOC=y, the smc->clcsock is unexpectedly changed
> in inet_init_csk_locks(). The INET_PROTOSW_ICSK flag is no need by smc,
> just remove it.
>
> After removing the INET_PROTOSW_ICSK flag, this patch alse revert
> commit 6fd27ea183c2 ("net/smc: fix lacks of icsk_syn_mss with IPPROTO_SMC")
> to avoid casting smc_sock to inet_connection_sock.
>
> Reported-by: syzbot+f775be4458668f7d220e@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=f775be4458668f7d220e
> Tested-by: syzbot+f775be4458668f7d220e@syzkaller.appspotmail.com
nit: looks like this diff is not tested by syzbot, you may
want to send diff to syzbot.
> Fixes: d25a92ccae6b ("net/smc: Introduce IPPROTO_SMC")
> Signed-off-by: Wang Liang <wangliang74@huawei.com>
Change itself looks good.
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Thanks!
在 2025/10/17 13:48, Kuniyuki Iwashima 写道:
> From: Wang Liang <wangliang74@huawei.com>
> Date: Fri, 17 Oct 2025 10:48:27 +0800
>> The syzbot report a crash:
>>
>> Oops: general protection fault, probably for non-canonical address 0xfbd5a5d5a0000003: 0000 [#1] SMP KASAN NOPTI
>> KASAN: maybe wild-memory-access in range [0xdead4ead00000018-0xdead4ead0000001f]
>> CPU: 1 UID: 0 PID: 6949 Comm: syz.0.335 Not tainted syzkaller #0 PREEMPT(full)
>> Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
>> RIP: 0010:smc_diag_msg_common_fill net/smc/smc_diag.c:44 [inline]
>> RIP: 0010:__smc_diag_dump.constprop.0+0x3ca/0x2550 net/smc/smc_diag.c:89
>> Call Trace:
>> <TASK>
>> smc_diag_dump_proto+0x26d/0x420 net/smc/smc_diag.c:217
>> smc_diag_dump+0x27/0x90 net/smc/smc_diag.c:234
>> netlink_dump+0x539/0xd30 net/netlink/af_netlink.c:2327
>> __netlink_dump_start+0x6d6/0x990 net/netlink/af_netlink.c:2442
>> netlink_dump_start include/linux/netlink.h:341 [inline]
>> smc_diag_handler_dump+0x1f9/0x240 net/smc/smc_diag.c:251
>> __sock_diag_cmd net/core/sock_diag.c:249 [inline]
>> sock_diag_rcv_msg+0x438/0x790 net/core/sock_diag.c:285
>> netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
>> netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
>> netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
>> netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
>> sock_sendmsg_nosec net/socket.c:714 [inline]
>> __sock_sendmsg net/socket.c:729 [inline]
>> ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
>> ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
>> __sys_sendmsg+0x16d/0x220 net/socket.c:2700
>> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>> do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
>> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>> </TASK>
>>
>> The process like this:
>>
>> (CPU1) | (CPU2)
>> ---------------------------------|-------------------------------
>> inet_create() |
>> // init clcsock to NULL |
>> sk = sk_alloc() |
>> |
>> // unexpectedly change clcsock |
>> inet_init_csk_locks() |
>> |
>> // add sk to hash table |
>> smc_inet_init_sock() |
>> smc_sk_init() |
>> smc_hash_sk() |
>> | // traverse the hash table
>> | smc_diag_dump_proto
>> | __smc_diag_dump()
>> | // visit wrong clcsock
>> | smc_diag_msg_common_fill()
>> // alloc clcsock |
>> smc_create_clcsk |
>> sock_create_kern |
>>
>> With CONFIG_DEBUG_LOCK_ALLOC=y, the smc->clcsock is unexpectedly changed
>> in inet_init_csk_locks(). The INET_PROTOSW_ICSK flag is no need by smc,
>> just remove it.
>>
>> After removing the INET_PROTOSW_ICSK flag, this patch alse revert
>> commit 6fd27ea183c2 ("net/smc: fix lacks of icsk_syn_mss with IPPROTO_SMC")
>> to avoid casting smc_sock to inet_connection_sock.
>>
>> Reported-by: syzbot+f775be4458668f7d220e@syzkaller.appspotmail.com
>> Closes: https://syzkaller.appspot.com/bug?extid=f775be4458668f7d220e
>> Tested-by: syzbot+f775be4458668f7d220e@syzkaller.appspotmail.com
> nit: looks like this diff is not tested by syzbot, you may
> want to send diff to syzbot.
>
Thank you for the reminder!
I just sent this diff to syzbot, and the test return OK:
https://lore.kernel.org/netdev/b76f348d-61d3-404b-81c6-57621a14046b@huawei.com/T/#t
------
Best regards
Wang Liang
>> Fixes: d25a92ccae6b ("net/smc: Introduce IPPROTO_SMC")
>> Signed-off-by: Wang Liang <wangliang74@huawei.com>
> Change itself looks good.
>
> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
>
> Thanks!
On Thu, Oct 16, 2025 at 10:51 PM Kuniyuki Iwashima <kuniyu@google.com> wrote:
>
> From: Wang Liang <wangliang74@huawei.com>
> Date: Fri, 17 Oct 2025 10:48:27 +0800
> > The syzbot report a crash:
> >
> > Oops: general protection fault, probably for non-canonical address 0xfbd5a5d5a0000003: 0000 [#1] SMP KASAN NOPTI
> > KASAN: maybe wild-memory-access in range [0xdead4ead00000018-0xdead4ead0000001f]
> > CPU: 1 UID: 0 PID: 6949 Comm: syz.0.335 Not tainted syzkaller #0 PREEMPT(full)
> > Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
> > RIP: 0010:smc_diag_msg_common_fill net/smc/smc_diag.c:44 [inline]
> > RIP: 0010:__smc_diag_dump.constprop.0+0x3ca/0x2550 net/smc/smc_diag.c:89
> > Call Trace:
> > <TASK>
> > smc_diag_dump_proto+0x26d/0x420 net/smc/smc_diag.c:217
> > smc_diag_dump+0x27/0x90 net/smc/smc_diag.c:234
> > netlink_dump+0x539/0xd30 net/netlink/af_netlink.c:2327
> > __netlink_dump_start+0x6d6/0x990 net/netlink/af_netlink.c:2442
> > netlink_dump_start include/linux/netlink.h:341 [inline]
> > smc_diag_handler_dump+0x1f9/0x240 net/smc/smc_diag.c:251
> > __sock_diag_cmd net/core/sock_diag.c:249 [inline]
> > sock_diag_rcv_msg+0x438/0x790 net/core/sock_diag.c:285
> > netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
> > netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
> > netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
> > netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
> > sock_sendmsg_nosec net/socket.c:714 [inline]
> > __sock_sendmsg net/socket.c:729 [inline]
> > ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
> > ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
> > __sys_sendmsg+0x16d/0x220 net/socket.c:2700
> > do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> > do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
> > entry_SYSCALL_64_after_hwframe+0x77/0x7f
> > </TASK>
> >
> > The process like this:
> >
> > (CPU1) | (CPU2)
> > ---------------------------------|-------------------------------
> > inet_create() |
> > // init clcsock to NULL |
> > sk = sk_alloc() |
> > |
> > // unexpectedly change clcsock |
> > inet_init_csk_locks() |
> > |
> > // add sk to hash table |
> > smc_inet_init_sock() |
> > smc_sk_init() |
> > smc_hash_sk() |
> > | // traverse the hash table
> > | smc_diag_dump_proto
> > | __smc_diag_dump()
> > | // visit wrong clcsock
> > | smc_diag_msg_common_fill()
> > // alloc clcsock |
> > smc_create_clcsk |
> > sock_create_kern |
> >
> > With CONFIG_DEBUG_LOCK_ALLOC=y, the smc->clcsock is unexpectedly changed
> > in inet_init_csk_locks(). The INET_PROTOSW_ICSK flag is no need by smc,
> > just remove it.
> >
> > After removing the INET_PROTOSW_ICSK flag, this patch alse revert
> > commit 6fd27ea183c2 ("net/smc: fix lacks of icsk_syn_mss with IPPROTO_SMC")
> > to avoid casting smc_sock to inet_connection_sock.
> >
> > Reported-by: syzbot+f775be4458668f7d220e@syzkaller.appspotmail.com
> > Closes: https://syzkaller.appspot.com/bug?extid=f775be4458668f7d220e
> > Tested-by: syzbot+f775be4458668f7d220e@syzkaller.appspotmail.com
>
> nit: looks like this diff is not tested by syzbot, you may
> want to send diff to syzbot.
>
>
> > Fixes: d25a92ccae6b ("net/smc: Introduce IPPROTO_SMC")
> > Signed-off-by: Wang Liang <wangliang74@huawei.com>
>
> Change itself looks good.
>
> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Agreed
Reviewed-by: Eric Dumazet <edumazet@google.com>
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