| Message ID | 20230207012046.8683-1-tung.q.nguyen@dektech.com.au (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,1/1] tipc: fix kernel warning when sending SYN message | expand |
On Tue, 7 Feb 2023 01:20:46 +0000 Tung Nguyen wrote: > When sending a SYN message, this kernel stack trace is observed: > > ... > [ 13.396352] RIP: 0010:_copy_from_iter+0xb4/0x550 > ... > [ 13.398494] Call Trace: > [ 13.398630] <TASK> > [ 13.398630] ? __alloc_skb+0xed/0x1a0 > [ 13.398630] tipc_msg_build+0x12c/0x670 [tipc] > [ 13.398630] ? shmem_add_to_page_cache.isra.71+0x151/0x290 > [ 13.398630] __tipc_sendmsg+0x2d1/0x710 [tipc] > [ 13.398630] ? tipc_connect+0x1d9/0x230 [tipc] > [ 13.398630] ? __local_bh_enable_ip+0x37/0x80 > [ 13.398630] tipc_connect+0x1d9/0x230 [tipc] > [ 13.398630] ? __sys_connect+0x9f/0xd0 > [ 13.398630] __sys_connect+0x9f/0xd0 > [ 13.398630] ? preempt_count_add+0x4d/0xa0 > [ 13.398630] ? fpregs_assert_state_consistent+0x22/0x50 > [ 13.398630] __x64_sys_connect+0x16/0x20 > [ 13.398630] do_syscall_64+0x42/0x90 > [ 13.398630] entry_SYSCALL_64_after_hwframe+0x63/0xcd > > It is because commit a41dad905e5a ("iov_iter: saner checks for attempt > to copy to/from iterator") has introduced sanity check for copying > from/to iov iterator. Lacking of copy direction from the iterator > viewpoint would lead to kernel stack trace like above. How far does the bug itself date, tho? Can we get a Fixes tag? > This commit fixes this issue by initializing the iov iterator with > the correct copy direction.
>-----Original Message----- >From: Jakub Kicinski <kuba@kernel.org> >Sent: Wednesday, February 8, 2023 12:35 PM >To: Tung Quang Nguyen <tung.q.nguyen@dektech.com.au> >Cc: netdev@vger.kernel.org; davem@davemloft.net; edumazet@google.com; pabeni@redhat.com; jmaloy@redhat.com; >ying.xue@windriver.com; viro@zeniv.linux.org.uk; syzbot+d43608d061e8847ec9f3@syzkaller.appspotmail.com >Subject: Re: [PATCH net 1/1] tipc: fix kernel warning when sending SYN message > >On Tue, 7 Feb 2023 01:20:46 +0000 Tung Nguyen wrote: >> When sending a SYN message, this kernel stack trace is observed: >> >> ... >> [ 13.396352] RIP: 0010:_copy_from_iter+0xb4/0x550 >> ... >> [ 13.398494] Call Trace: >> [ 13.398630] <TASK> >> [ 13.398630] ? __alloc_skb+0xed/0x1a0 >> [ 13.398630] tipc_msg_build+0x12c/0x670 [tipc] >> [ 13.398630] ? shmem_add_to_page_cache.isra.71+0x151/0x290 >> [ 13.398630] __tipc_sendmsg+0x2d1/0x710 [tipc] >> [ 13.398630] ? tipc_connect+0x1d9/0x230 [tipc] >> [ 13.398630] ? __local_bh_enable_ip+0x37/0x80 >> [ 13.398630] tipc_connect+0x1d9/0x230 [tipc] >> [ 13.398630] ? __sys_connect+0x9f/0xd0 >> [ 13.398630] __sys_connect+0x9f/0xd0 >> [ 13.398630] ? preempt_count_add+0x4d/0xa0 >> [ 13.398630] ? fpregs_assert_state_consistent+0x22/0x50 >> [ 13.398630] __x64_sys_connect+0x16/0x20 >> [ 13.398630] do_syscall_64+0x42/0x90 >> [ 13.398630] entry_SYSCALL_64_after_hwframe+0x63/0xcd >> >> It is because commit a41dad905e5a ("iov_iter: saner checks for attempt >> to copy to/from iterator") has introduced sanity check for copying >> from/to iov iterator. Lacking of copy direction from the iterator >> viewpoint would lead to kernel stack trace like above. > >How far does the bug itself date, tho? This issue appeared since the introduction of commit a41dad905e5a in December 2022. >Can we get a Fixes tag? I will add a Fixes tag in v2. > >> This commit fixes this issue by initializing the iov iterator with >> the correct copy direction.
>-----Original Message----- >From: Jakub Kicinski <kuba@kernel.org> >Sent: Wednesday, February 8, 2023 2:31 PM >To: Tung Quang Nguyen <tung.q.nguyen@dektech.com.au> >Cc: netdev@vger.kernel.org; davem@davemloft.net; edumazet@google.com; pabeni@redhat.com; jmaloy@redhat.com; >ying.xue@windriver.com; viro@zeniv.linux.org.uk; syzbot+d43608d061e8847ec9f3@syzkaller.appspotmail.com" ><syzbot+d43608d061e8847ec9f3@syzkaller.appspotmail.com> >Subject: Re: [PATCH net 1/1] tipc: fix kernel warning when sending SYN message > >On Wed, 8 Feb 2023 06:56:26 +0000 Tung Quang Nguyen wrote: >> >> It is because commit a41dad905e5a ("iov_iter: saner checks for attempt >> >> to copy to/from iterator") has introduced sanity check for copying >> >> from/to iov iterator. Lacking of copy direction from the iterator >> >> viewpoint would lead to kernel stack trace like above. >> > >> >How far does the bug itself date, tho? >> This issue appeared since the introduction of commit a41dad905e5a in December 2022. > >I presume that commit a41dad905e5a just added a warning to catch >abuses. Unless this is a false positive the bug itself must have >been introduced earlier. Yes, since 2014. I added in v2 > >> >Can we get a Fixes tag? >> I will add a Fixes tag in v2. > >Thanks!
diff --git a/net/tipc/msg.c b/net/tipc/msg.c index 5c9fd4791c4b..cce118fea07a 100644 --- a/net/tipc/msg.c +++ b/net/tipc/msg.c @@ -381,6 +381,9 @@ int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m, int offset, msg_set_size(mhdr, msz); + if (!dsz) + iov_iter_init(&m->msg_iter, ITER_SOURCE, NULL, 0, 0); + /* No fragmentation needed? */ if (likely(msz <= pktmax)) { skb = tipc_buf_acquire(msz, GFP_KERNEL);
When sending a SYN message, this kernel stack trace is observed: ... [ 13.396352] RIP: 0010:_copy_from_iter+0xb4/0x550 ... [ 13.398494] Call Trace: [ 13.398630] <TASK> [ 13.398630] ? __alloc_skb+0xed/0x1a0 [ 13.398630] tipc_msg_build+0x12c/0x670 [tipc] [ 13.398630] ? shmem_add_to_page_cache.isra.71+0x151/0x290 [ 13.398630] __tipc_sendmsg+0x2d1/0x710 [tipc] [ 13.398630] ? tipc_connect+0x1d9/0x230 [tipc] [ 13.398630] ? __local_bh_enable_ip+0x37/0x80 [ 13.398630] tipc_connect+0x1d9/0x230 [tipc] [ 13.398630] ? __sys_connect+0x9f/0xd0 [ 13.398630] __sys_connect+0x9f/0xd0 [ 13.398630] ? preempt_count_add+0x4d/0xa0 [ 13.398630] ? fpregs_assert_state_consistent+0x22/0x50 [ 13.398630] __x64_sys_connect+0x16/0x20 [ 13.398630] do_syscall_64+0x42/0x90 [ 13.398630] entry_SYSCALL_64_after_hwframe+0x63/0xcd It is because commit a41dad905e5a ("iov_iter: saner checks for attempt to copy to/from iterator") has introduced sanity check for copying from/to iov iterator. Lacking of copy direction from the iterator viewpoint would lead to kernel stack trace like above. This commit fixes this issue by initializing the iov iterator with the correct copy direction. Reported-by: syzbot+d43608d061e8847ec9f3@syzkaller.appspotmail.com Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au> --- net/tipc/msg.c | 3 +++ 1 file changed, 3 insertions(+)