* [PATCH] fs/9p: Compare qid.path in v9fs_test_inode
@ 2017-02-22 0:06 Tuomas Tynkkynen
2017-03-08 13:46 ` Tuomas Tynkkynen
2017-03-09 17:26 ` Latchesar Ionkov
0 siblings, 2 replies; 3+ messages in thread
From: Tuomas Tynkkynen @ 2017-02-22 0:06 UTC (permalink / raw)
To: Alexander Viro
Cc: linux-fsdevel, Eric Van Hensbergen, v9fs-developer, linux-kernel,
Aneesh Kumar K . V, Tuomas Tynkkynen, stable
Commit fd2421f54423 ("fs/9p: When doing inode lookup compare qid details
and inode mode bits.") transformed v9fs_qid_iget() to use iget5_locked()
instead of iget_locked(). However, the test() callback is not checking
fid.path at all, which means that a lookup in the inode cache can now
accidentally locate a completely wrong inode from the same inode hash
bucket if the other fields (qid.type and qid.version) match.
Fixes: fd2421f54423 ("fs/9p: When doing inode lookup compare qid details and inode mode bits.")
Cc: stable@vger.kernel.org
Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com>
---
Does this sound sensible? I have never reproduced the problem myself but
reportedly this patch solves some really weird problems where the
symptoms match (wrong files being opened unpredictably).
---
fs/9p/vfs_inode.c | 3 +++
fs/9p/vfs_inode_dotl.c | 3 +++
2 files changed, 6 insertions(+)
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 30ca770c5e0b..f8ab4a66acaf 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -483,6 +483,9 @@ static int v9fs_test_inode(struct inode *inode, void *data)
if (v9inode->qid.type != st->qid.type)
return 0;
+
+ if (v9inode->qid.path != st->qid.path)
+ return 0;
return 1;
}
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index afaa4b6de801..c3dd0d42bb3a 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -87,6 +87,9 @@ static int v9fs_test_inode_dotl(struct inode *inode, void *data)
if (v9inode->qid.type != st->qid.type)
return 0;
+
+ if (v9inode->qid.path != st->qid.path)
+ return 0;
return 1;
}
--
2.11.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] fs/9p: Compare qid.path in v9fs_test_inode
2017-02-22 0:06 [PATCH] fs/9p: Compare qid.path in v9fs_test_inode Tuomas Tynkkynen
@ 2017-03-08 13:46 ` Tuomas Tynkkynen
2017-03-09 17:26 ` Latchesar Ionkov
1 sibling, 0 replies; 3+ messages in thread
From: Tuomas Tynkkynen @ 2017-03-08 13:46 UTC (permalink / raw)
To: Alexander Viro
Cc: linux-fsdevel, Eric Van Hensbergen, v9fs-developer, linux-kernel,
Aneesh Kumar K . V, stable
On Wed, 22 Feb 2017 02:06:29 +0200
Tuomas Tynkkynen <tuomas@tuxera.com> wrote:
> Commit fd2421f54423 ("fs/9p: When doing inode lookup compare qid details
> and inode mode bits.") transformed v9fs_qid_iget() to use iget5_locked()
> instead of iget_locked(). However, the test() callback is not checking
> fid.path at all, which means that a lookup in the inode cache can now
> accidentally locate a completely wrong inode from the same inode hash
> bucket if the other fields (qid.type and qid.version) match.
>
Al, does this sound sensible? (or if there is someone else picking up 9p
patches, let me know).
Thanks!
- Tuomas
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] fs/9p: Compare qid.path in v9fs_test_inode
2017-02-22 0:06 [PATCH] fs/9p: Compare qid.path in v9fs_test_inode Tuomas Tynkkynen
2017-03-08 13:46 ` Tuomas Tynkkynen
@ 2017-03-09 17:26 ` Latchesar Ionkov
1 sibling, 0 replies; 3+ messages in thread
From: Latchesar Ionkov @ 2017-03-09 17:26 UTC (permalink / raw)
To: Tuomas Tynkkynen
Cc: Alexander Viro, linux-fsdevel, Eric Van Hensbergen,
V9FS Developers, Linux Kernel, Aneesh Kumar K . V, stable
Reviewed-by: Latchesar Ionkov <lucho@ionkov.net>
On Tue, Feb 21, 2017 at 6:06 PM, Tuomas Tynkkynen <tuomas@tuxera.com> wrote:
> Commit fd2421f54423 ("fs/9p: When doing inode lookup compare qid details
> and inode mode bits.") transformed v9fs_qid_iget() to use iget5_locked()
> instead of iget_locked(). However, the test() callback is not checking
> fid.path at all, which means that a lookup in the inode cache can now
> accidentally locate a completely wrong inode from the same inode hash
> bucket if the other fields (qid.type and qid.version) match.
>
> Fixes: fd2421f54423 ("fs/9p: When doing inode lookup compare qid details and inode mode bits.")
> Cc: stable@vger.kernel.org
> Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com>
> ---
> Does this sound sensible? I have never reproduced the problem myself but
> reportedly this patch solves some really weird problems where the
> symptoms match (wrong files being opened unpredictably).
> ---
> fs/9p/vfs_inode.c | 3 +++
> fs/9p/vfs_inode_dotl.c | 3 +++
> 2 files changed, 6 insertions(+)
>
> diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
> index 30ca770c5e0b..f8ab4a66acaf 100644
> --- a/fs/9p/vfs_inode.c
> +++ b/fs/9p/vfs_inode.c
> @@ -483,6 +483,9 @@ static int v9fs_test_inode(struct inode *inode, void *data)
>
> if (v9inode->qid.type != st->qid.type)
> return 0;
> +
> + if (v9inode->qid.path != st->qid.path)
> + return 0;
> return 1;
> }
>
> diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
> index afaa4b6de801..c3dd0d42bb3a 100644
> --- a/fs/9p/vfs_inode_dotl.c
> +++ b/fs/9p/vfs_inode_dotl.c
> @@ -87,6 +87,9 @@ static int v9fs_test_inode_dotl(struct inode *inode, void *data)
>
> if (v9inode->qid.type != st->qid.type)
> return 0;
> +
> + if (v9inode->qid.path != st->qid.path)
> + return 0;
> return 1;
> }
>
> --
> 2.11.1
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-03-08 13:46 ` Tuomas Tynkkynen
2017-03-09 17:26 ` Latchesar Ionkov
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