From: Matthew Wilcox <willy@infradead.org>
To: syzbot <syzbot+8645fe63c4d22c8d27b8@syzkaller.appspotmail.com>
Cc: akpm@linux-foundation.org, liam.howlett@oracle.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [mm?] WARNING: suspicious RCU usage in mas_walk (2)
Date: Thu, 27 Jul 2023 19:56:20 +0100 [thread overview]
Message-ID: <ZMK91N6V245iS1qu@casper.infradead.org> (raw)
In-Reply-To: <0000000000000aeb7f06015e5cbd@google.com>
On Tue, Jul 25, 2023 at 11:57:22PM -0700, syzbot wrote:
> syzbot has bisected this issue to:
>
> commit a52f58b34afe095ebc5823684eb264404dad6f7b
> Author: Matthew Wilcox (Oracle) <willy@infradead.org>
> Date: Mon Jul 24 18:54:10 2023 +0000
>
> mm: handle faults that merely update the accessed bit under the VMA lock
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1783585ea80000
> start commit: [unknown]
> git tree: linux-next
#syz test git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next next-20230727
diff --git a/mm/memory.c b/mm/memory.c
index 20a2e9ed4aeb..57b271108bdc 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3567,6 +3567,12 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf)
return 0;
}
copy:
+ if ((vmf->flags & FAULT_FLAG_VMA_LOCK) && !vma->anon_vma) {
+ pte_unmap_unlock(vmf->pte, vmf->ptl);
+ vma_end_read(vmf->vma);
+ return VM_FAULT_RETRY;
+ }
+
/*
* Ok, we need to copy. Oh, well..
*/
next prev parent reply other threads:[~2023-07-27 18:56 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-06 3:12 [syzbot] [mm?] WARNING: suspicious RCU usage in mas_walk (2) syzbot
2023-07-06 16:53 ` Liam R. Howlett
2023-07-25 20:27 ` syzbot
2023-07-26 6:57 ` syzbot
2023-07-27 16:47 ` Liam R. Howlett
[not found] ` <CAJuCfpEyE18kbH84FfmfzUnar2dxgzpi=FOYPbU8MOpz-SbVjg@mail.gmail.com>
2023-07-27 17:59 ` Jann Horn
2023-07-27 18:12 ` Liam R. Howlett
2023-07-27 18:17 ` Matthew Wilcox
2023-07-27 18:31 ` Suren Baghdasaryan
2023-07-27 18:46 ` Matthew Wilcox
2023-07-27 19:20 ` Jann Horn
2023-07-27 20:08 ` Matthew Wilcox
2023-07-27 18:50 ` Matthew Wilcox
2023-07-27 18:50 ` syzbot
2023-07-27 18:52 ` Matthew Wilcox
2023-07-27 18:53 ` syzbot
2023-07-27 18:54 ` Matthew Wilcox
2023-07-27 19:12 ` Aleksandr Nogikh
2023-07-27 18:56 ` Matthew Wilcox [this message]
2023-07-27 19:17 ` syzbot
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