Re: Reminder: 3 open syzbot bugs in vhost subsystem

From: Jason Wang
Date: Tue Jul 23 2019 - 23:05:23 EST



On 2019/7/24 äå10:38, Eric Biggers wrote:
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Of the currently open syzbot reports against the upstream kernel, I've manually
marked 3 of them as possibly being bugs in the vhost subsystem. I've listed
these reports below, sorted by an algorithm that tries to list first the reports
most likely to be still valid, important, and actionable.

Of these 3 bugs, 2 were seen in mainline in the last week.

Of these 3 bugs, 2 were bisected to commits from the following person:

Jason Wang <jasowang@xxxxxxxxxx>

If you believe a bug is no longer valid, please close the syzbot report by
sending a '#syz fix', '#syz dup', or '#syz invalid' command in reply to the
original thread, as explained at https://goo.gl/tpsmEJ#status

If you believe I misattributed a bug to the vhost subsystem, please let me know,
and if possible forward the report to the correct people or mailing list.

Here are the bugs:

--------------------------------------------------------------------------------
Title: KASAN: use-after-free Write in tlb_finish_mmu
Last occurred: 5 days ago
Reported: 4 days ago
Branches: Mainline
Dashboard link: https://syzkaller.appspot.com/bug?id=d57b94f89e48c85ef7d95acc208209ea4bdc10de
Original thread: https://lkml.kernel.org/lkml/00000000000045e7a1058e02458a@xxxxxxxxxx/T/#u

This bug has a syzkaller reproducer only.

This bug was bisected to:

commit 7f466032dc9e5a61217f22ea34b2df932786bbfc
Author: Jason Wang <jasowang@xxxxxxxxxx>
Date: Fri May 24 08:12:18 2019 +0000

ÂÂvhost: access vq metadata through kernel virtual address

No one has replied to the original thread for this bug yet.

If you fix this bug, please add the following tag to the commit:
Reported-by: syzbot+8267e9af795434ffadad@xxxxxxxxxxxxxxxxxxxxxxxxx

If you send any email or patch for this bug, please reply to the original
thread. For the git send-email command to use, or tips on how to reply if the
thread isn't in your mailbox, see the "Reply instructions" at
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--------------------------------------------------------------------------------
Title: KASAN: use-after-free Read in finish_task_switch (2)
Last occurred: 5 days ago
Reported: 4 days ago
Branches: Mainline
Dashboard link: https://syzkaller.appspot.com/bug?id=9a98fcad6c8bd31f5c3afbdc6c75de9f082c0ffa
Original thread: https://lkml.kernel.org/lkml/000000000000490679058e0245ee@xxxxxxxxxx/T/#u

This bug has a syzkaller reproducer only.

This bug was bisected to:

commit 7f466032dc9e5a61217f22ea34b2df932786bbfc
Author: Jason Wang <jasowang@xxxxxxxxxx>
Date: Fri May 24 08:12:18 2019 +0000

ÂÂvhost: access vq metadata through kernel virtual address

No one has replied to the original thread for this bug yet.


Hi:

We believe above two bugs are duplicated with the report "WARNING in __mmdrop". Can I just dup them with

#syz dup "WARNING in __mmdrop"

(If yes, just wonder how syzbot differ bugs, technically, several different bug can hit the same warning).



If you fix this bug, please add the following tag to the commit:
Reported-by: syzbot+7f067c796eee2acbc57a@xxxxxxxxxxxxxxxxxxxxxxxxx

If you send any email or patch for this bug, please reply to the original
thread. For the git send-email command to use, or tips on how to reply if the
thread isn't in your mailbox, see the "Reply instructions" at
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--------------------------------------------------------------------------------
Title: memory leak in vhost_net_ioctl
Last occurred: 22 days ago
Reported: 48 days ago
Branches: Mainline
Dashboard link: https://syzkaller.appspot.com/bug?id=12ba349d7e26ccfe95317bc376e812ebbae2ee0f
Original thread: https://lkml.kernel.org/lkml/000000000000188da1058a9c25e3@xxxxxxxxxx/T/#u

This bug has a C reproducer.

The original thread for this bug has received 4 replies; the last was 39 days
ago.

If you fix this bug, please add the following tag to the commit:
Reported-by: syzbot+0789f0c7e45efd7bb643@xxxxxxxxxxxxxxxxxxxxxxxxx


I do remember it can not be reproduced upstream, let me double check and close this one.

Thanks



If you send any email or patch for this bug, please consider replying to the
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