[PULL 0/1] 9p fixes for QEMU 4.2-rc3

[PULL 0/1] 9p fixes for QEMU 4.2-rc3

[Greg Kurz]

The following changes since commit 2061735ff09f9d5e67c501a96227b470e7de69b1:

  Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging (2019-11-21 17:18:40 +0000)

are available in the Git repository at:

  https://github.com/gkurz/qemu.git tags/9p-fix-2019-11-23

for you to fetch changes up to 68d654daee4364a0eca589a547d716084d9cb33d:

  9pfs: Fix divide by zero bug (2019-11-23 15:51:48 +0100)

----------------------------------------------------------------
9pfs fixes for QEMU 4.2

This fixes a potential QEMU crash if the underlying filesystem returns
a null block size in statfs().

----------------------------------------------------------------
Dan Schatzberg (1):
      9pfs: Fix divide by zero bug

 hw/9pfs/9p.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
-- 
2.21.0

[PULL 1/1] 9pfs: Fix divide by zero bug

[Greg Kurz]

From: Dan Schatzberg <dschatzberg@fb.com>

Some filesystems may return 0s in statfs (trivially, a FUSE filesystem
can do so). QEMU should handle this gracefully and just behave the
same as if statfs failed.

Signed-off-by: Dan Schatzberg <dschatzberg@fb.com>
Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
---
 hw/9pfs/9p.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index 37abcdb71ec0..520177f40c17 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -1834,8 +1834,10 @@ static int32_t coroutine_fn get_iounit(V9fsPDU *pdu, V9fsPath *path)
      * and as well as less than (client msize - P9_IOHDRSZ))
      */
     if (!v9fs_co_statfs(pdu, path, &stbuf)) {
-        iounit = stbuf.f_bsize;
-        iounit *= (s->msize - P9_IOHDRSZ)/stbuf.f_bsize;
+        if (stbuf.f_bsize) {
+            iounit = stbuf.f_bsize;
+            iounit *= (s->msize - P9_IOHDRSZ) / stbuf.f_bsize;
+        }
     }
     if (!iounit) {
         iounit = s->msize - P9_IOHDRSZ;
-- 
2.21.0

Re: [PULL 0/1] 9p fixes for QEMU 4.2-rc3

[Peter Maydell]

On Sat, 23 Nov 2019 at 16:59, Greg Kurz <groug@kaod.org> wrote:
>
> The following changes since commit 2061735ff09f9d5e67c501a96227b470e7de69b1:
>
>   Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging (2019-11-21 17:18:40 +0000)
>
> are available in the Git repository at:
>
>   https://github.com/gkurz/qemu.git tags/9p-fix-2019-11-23
>
> for you to fetch changes up to 68d654daee4364a0eca589a547d716084d9cb33d:
>
>   9pfs: Fix divide by zero bug (2019-11-23 15:51:48 +0100)
>
> ----------------------------------------------------------------
> 9pfs fixes for QEMU 4.2
>
> This fixes a potential QEMU crash if the underlying filesystem returns
> a null block size in statfs().
>
> ----------------------------------------------------------------
> Dan Schatzberg (1):
>       9pfs: Fix divide by zero bug
>
>  hw/9pfs/9p.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> --
> 2.21.0


Applied, thanks.

Please update the changelog at https://wiki.qemu.org/ChangeLog/4.2
for any user-visible changes.

-- PMM