From: Alexey Kardashevskiy <aik@ozlabs.ru>
To: v9fs-developer@lists.sourceforge.net
Cc: Greg Kurz <groug@kaod.org>,
Dominique Martinet <asmadeus@codewreck.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: 9p/trans_fd lockup
Date: Thu, 6 Aug 2020 21:08:26 +1000 [thread overview]
Message-ID: <9d8a8abf-7968-2752-89e7-bac39ae91999@ozlabs.ru> (raw)
Hi!
I am seeing another bug in 9p under syzkaller, the reprocase is:
r0 = open$dir(&(0x7f0000000040)='./file0\x00', 0x88142, 0x182)
r1 = openat$null(0xffffffffffffff9c, &(0x7f0000000640)='/dev/null\x00',
0x0, 0x0)
mount$9p_fd(0x0, &(0x7f0000000000)='./file0\x00',
&(0x7f00000000c0)='9p\x00', 0x0, &(0x7f0000000100)={'trans=fd,',
{'rfdno', 0x3d, r1}, 0x2$, {'wfdno', 0x3d, r0}})
The default behaviour of syzkaller is to call syscalls concurrently (I
think), at least it forks by default and executes the same sequence in
both threads.
In this example both threads makes it to:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/net/9p/client.c?h=v5.8#n757
and sit there with the only difference which is thread#1 goes via
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/net/9p/client.c?h=v5.8#n767
I am pretty sure things should not have gone that far but I cannot
clearly see what needs fixing. Ideas? Thanks,
--
Alexey
next reply other threads:[~2020-08-06 12:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-06 11:08 Alexey Kardashevskiy [this message]
2020-08-06 12:38 ` 9p/trans_fd lockup Dominique Martinet
2020-08-07 1:43 ` Alexey Kardashevskiy
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