Re: PROBLEM: Kernel oops when mounting a encryptData CIFS share with CONFIG_DEBUG_VIRTUAL

[Steve French <smfrench@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 1657 bytes --]

Sebastien,
I cleaned up the patch and merged into cifs-2.6.git - can you
doublecheck it is correct?


On Thu, Jul 25, 2019 at 3:35 PM Pavel Shilovsky
<pavel.shilovsky@gmail.com> wrote:
>
> чт, 25 июл. 2019 г. в 09:57, Sebastien Tisserant via samba-technical
> <samba-technical@lists.samba.org>:
> ...
> >
> > mount works without CONFIG_DEBUG_VIRTUAL
> >
> > If we don't set CONFIG_VMAP_STACK mount works with CONFIG_DEBUG_VIRTUAL
> >
> >
> > We have the following (very quick and dirty) patch :
> >
> > Index: linux-4.19.60/fs/cifs/smb2ops.c
> > ===================================================================
> > --- linux-4.19.60.orig/fs/cifs/smb2ops.c
> > +++ linux-4.19.60/fs/cifs/smb2ops.c
> > @@ -2545,7 +2545,15 @@ fill_transform_hdr(struct smb2_transform
> >  static inline void smb2_sg_set_buf(struct scatterlist *sg, const void *buf,
> >                     unsigned int buflen)
> >  {
> > -    sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
> > +      void *addr;
> > +      /*
> > +       * VMAP_STACK (at least) puts stack into the vmalloc address space
> > +      */
> > +      if (is_vmalloc_addr(buf))
> > +              addr = vmalloc_to_page(buf);
> > +      else
> > +              addr = virt_to_page(buf);
> > +      sg_set_page(sg, addr, buflen, offset_in_page(buf));
> >  }
> >
> >  /* Assumes the first rqst has a transform header as the first iov.
> >
> >
>
> Thanks for reporting this. The patch looks good to me. Did you test
> your scenario all together with it (not only mounting)?
>
>
> Best regards,
> Pavel Shilovskiy



-- 
Thanks,

Steve

[-- Attachment #2: 0001-SMB3-Kernel-oops-mounting-a-encryptData-share-with-C.patch --]
[-- Type: text/x-patch, Size: 1276 bytes --]

From e7afda65be3198639de0fcf1796ddd0a101e1ab1 Mon Sep 17 00:00:00 2001
From: Sebastien Tisserant <stisserant@wallix.com>
Date: Thu, 1 Aug 2019 12:06:08 -0500
Subject: [PATCH] SMB3: Kernel oops mounting a encryptData share with
 CONFIG_DEBUG_VIRTUAL

Fix kernel oops when mounting a encryptData CIFS share with
CONFIG_DEBUG_VIRTUAL

Signed-off-by: Sebastien Tisserant <stisserant@wallix.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
---
 fs/cifs/smb2ops.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index fc464dc20b30..3e3243d7152c 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3510,7 +3510,15 @@ fill_transform_hdr(struct smb2_transform_hdr *tr_hdr, unsigned int orig_len,
 static inline void smb2_sg_set_buf(struct scatterlist *sg, const void *buf,
 				   unsigned int buflen)
 {
-	sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
+	void *addr;
+	/*
+	 * VMAP_STACK (at least) puts stack into the vmalloc address space
+	 */
+	if (is_vmalloc_addr(buf))
+		addr = vmalloc_to_page(buf);
+	else
+		addr = virt_to_page(buf);
+	sg_set_page(sg, addr, buflen, offset_in_page(buf));
 }
 
 /* Assumes the first rqst has a transform header as the first iov.
-- 
2.20.1