FAILED: patch "[PATCH] XArray: Fix xa_find_next for large multi-index entries" failed to apply to 5.4-stable tree

FAILED: patch "[PATCH] XArray: Fix xa_find_next for large multi-index entries" failed to apply to 5.4-stable tree

[gregkh]

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From bd40b17ca49d7d110adf456e647701ce74de2241 Mon Sep 17 00:00:00 2001
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: Fri, 31 Jan 2020 05:07:55 -0500
Subject: [PATCH] XArray: Fix xa_find_next for large multi-index entries

Coverity pointed out that xas_sibling() was shifting xa_offset without
promoting it to an unsigned long first, so the shift could cause an
overflow and we'd get the wrong answer.  The fix is obvious, and the
new test-case provokes UBSAN to report an error:
runtime error: shift exponent 60 is too large for 32-bit type 'int'

Fixes: 19c30f4dd092 ("XArray: Fix xa_find_after with multi-index entries")
Reported-by: Bjorn Helgaas <bhelgaas@google.com>
Reported-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: stable@vger.kernel.org

diff --git a/lib/test_xarray.c b/lib/test_xarray.c
index 55c14e8c8859..8c7d7a8468b8 100644
--- a/lib/test_xarray.c
+++ b/lib/test_xarray.c
@@ -12,6 +12,9 @@
 static unsigned int tests_run;
 static unsigned int tests_passed;
 
+static const unsigned int order_limit =
+		IS_ENABLED(CONFIG_XARRAY_MULTI) ? BITS_PER_LONG : 1;
+
 #ifndef XA_DEBUG
 # ifdef __KERNEL__
 void xa_dump(const struct xarray *xa) { }
@@ -959,6 +962,20 @@ static noinline void check_multi_find_2(struct xarray *xa)
 	}
 }
 
+static noinline void check_multi_find_3(struct xarray *xa)
+{
+	unsigned int order;
+
+	for (order = 5; order < order_limit; order++) {
+		unsigned long index = 1UL << (order - 5);
+
+		XA_BUG_ON(xa, !xa_empty(xa));
+		xa_store_order(xa, 0, order - 4, xa_mk_index(0), GFP_KERNEL);
+		XA_BUG_ON(xa, xa_find_after(xa, &index, ULONG_MAX, XA_PRESENT));
+		xa_erase_index(xa, 0);
+	}
+}
+
 static noinline void check_find_1(struct xarray *xa)
 {
 	unsigned long i, j, k;
@@ -1081,6 +1098,7 @@ static noinline void check_find(struct xarray *xa)
 	for (i = 2; i < 10; i++)
 		check_multi_find_1(xa, i);
 	check_multi_find_2(xa);
+	check_multi_find_3(xa);
 }
 
 /* See find_swap_entry() in mm/shmem.c */
diff --git a/lib/xarray.c b/lib/xarray.c
index 1d9fab7db8da..acd1fad2e862 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -1839,7 +1839,8 @@ static bool xas_sibling(struct xa_state *xas)
 	if (!node)
 		return false;
 	mask = (XA_CHUNK_SIZE << node->shift) - 1;
-	return (xas->xa_index & mask) > (xas->xa_offset << node->shift);
+	return (xas->xa_index & mask) >
+		((unsigned long)xas->xa_offset << node->shift);
 }
 
 /**

Re: FAILED: patch "[PATCH] XArray: Fix xa_find_next for large multi-index entries" failed to apply to 5.4-stable tree

[Matthew Wilcox]

On Wed, Apr 15, 2020 at 01:04:37PM +0200, gregkh@linuxfoundation.org wrote:
> The patch below does not apply to the 5.4-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
> 
> thanks,
> 
> greg k-h
> 
> ------------------ original commit in Linus's tree ------------------
> 
> >From bd40b17ca49d7d110adf456e647701ce74de2241 Mon Sep 17 00:00:00 2001

Seems like it's already there as commit
16696ee7b58101c90bf21c3ab2443c57df4af24e

Re: FAILED: patch "[PATCH] XArray: Fix xa_find_next for large multi-index entries" failed to apply to 5.4-stable tree

[Greg KH]

On Wed, Apr 15, 2020 at 08:02:22AM -0700, Matthew Wilcox wrote:
> On Wed, Apr 15, 2020 at 01:04:37PM +0200, gregkh@linuxfoundation.org wrote:
> > The patch below does not apply to the 5.4-stable tree.
> > If someone wants it applied there, or to any other stable or longterm
> > tree, then please email the backport, including the original git commit
> > id to <stable@vger.kernel.org>.
> > 
> > thanks,
> > 
> > greg k-h
> > 
> > ------------------ original commit in Linus's tree ------------------
> > 
> > >From bd40b17ca49d7d110adf456e647701ce74de2241 Mon Sep 17 00:00:00 2001
> 
> Seems like it's already there as commit
> 16696ee7b58101c90bf21c3ab2443c57df4af24e

Ugh.

Sasha, your scripts are applying patches to older kernels before newer
ones for some odd reason again, which confuses mine to no end :(


thanks,

greg k-h

Re: FAILED: patch "[PATCH] XArray: Fix xa_find_next for large multi-index entries" failed to apply to 5.4-stable tree

[Sasha Levin]

On Wed, Apr 15, 2020 at 06:51:22PM +0200, Greg KH wrote:
>On Wed, Apr 15, 2020 at 08:02:22AM -0700, Matthew Wilcox wrote:
>> On Wed, Apr 15, 2020 at 01:04:37PM +0200, gregkh@linuxfoundation.org wrote:
>> > The patch below does not apply to the 5.4-stable tree.
>> > If someone wants it applied there, or to any other stable or longterm
>> > tree, then please email the backport, including the original git commit
>> > id to <stable@vger.kernel.org>.
>> >
>> > thanks,
>> >
>> > greg k-h
>> >
>> > ------------------ original commit in Linus's tree ------------------
>> >
>> > >From bd40b17ca49d7d110adf456e647701ce74de2241 Mon Sep 17 00:00:00 2001
>>
>> Seems like it's already there as commit
>> 16696ee7b58101c90bf21c3ab2443c57df4af24e
>
>Ugh.
>
>Sasha, your scripts are applying patches to older kernels before newer
>ones for some odd reason again, which confuses mine to no end :(

/me scratches head

It's in 5.6, 5.5, and 5.4. I've also queued them all at the same time
and you've released them all at the same time (Apr 8th).

Yes, it's tagged for stable, but I've grabbed it for the Fixes: tag.

What am I missing?

-- 
Thanks,
Sasha

Re: FAILED: patch "[PATCH] XArray: Fix xa_find_next for large multi-index entries" failed to apply to 5.4-stable tree

[Greg KH]

On Wed, Apr 15, 2020 at 06:49:49PM -0400, Sasha Levin wrote:
> On Wed, Apr 15, 2020 at 06:51:22PM +0200, Greg KH wrote:
> > On Wed, Apr 15, 2020 at 08:02:22AM -0700, Matthew Wilcox wrote:
> > > On Wed, Apr 15, 2020 at 01:04:37PM +0200, gregkh@linuxfoundation.org wrote:
> > > > The patch below does not apply to the 5.4-stable tree.
> > > > If someone wants it applied there, or to any other stable or longterm
> > > > tree, then please email the backport, including the original git commit
> > > > id to <stable@vger.kernel.org>.
> > > >
> > > > thanks,
> > > >
> > > > greg k-h
> > > >
> > > > ------------------ original commit in Linus's tree ------------------
> > > >
> > > > >From bd40b17ca49d7d110adf456e647701ce74de2241 Mon Sep 17 00:00:00 2001
> > > 
> > > Seems like it's already there as commit
> > > 16696ee7b58101c90bf21c3ab2443c57df4af24e
> > 
> > Ugh.
> > 
> > Sasha, your scripts are applying patches to older kernels before newer
> > ones for some odd reason again, which confuses mine to no end :(
> 
> /me scratches head
> 
> It's in 5.6, 5.5, and 5.4. I've also queued them all at the same time
> and you've released them all at the same time (Apr 8th).
> 
> Yes, it's tagged for stable, but I've grabbed it for the Fixes: tag.
> 
> What am I missing?

{sigh} nothing, my fault, it was a long day of stable patches, all is
fine :)

greg k-h