Re: [added to the 4.1 stable tree] tmpfs: don't undo fallocate past its last page

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, 12 Jul 2016, Vlastimil Babka wrote:
> On 07/12/2016 04:52 AM, Sasha Levin wrote:
> > From: Anthony Romano <anthony.romano@xxxxxxxxxx>
> > 
> > This patch has been added to the 4.1 stable tree. If you have any
> > objections, please let us know.
> 
> Hugh says the patch is broken, shouldn't go to stable without the fix:
> http://marc.info/?l=linux-mm&m=146819440406829&w=2

Thanks, Vlastimil: yes, this patch here should not go in without
upstream commit 7f556567036cb7f89aabe2f0954b08566b4efb53
("tmpfs: fix regression hang in fallocate undo")
on top.  And of course the same applies to 3.18.

Hugh

> 
> > ===============
> > 
> > [ Upstream commit b9b4bb26af017dbe930cd4df7f9b2fc3a0497bfe ]
> > 
> > When fallocate is interrupted it will undo a range that extends one byte
> > past its range of allocated pages.  This can corrupt an in-use page by
> > zeroing out its first byte.  Instead, undo using the inclusive byte
> > range.
> > 
> > Fixes: 1635f6a74152f1d ("tmpfs: undo fallocation on failure")
> > Link:
> > http://lkml.kernel.org/r/1462713387-16724-1-git-send-email-anthony.romano@xxxxxxxxxx
> > Signed-off-by: Anthony Romano <anthony.romano@xxxxxxxxxx>
> > Cc: Vlastimil Babka <vbabka@xxxxxxx>
> > Cc: Hugh Dickins <hughd@xxxxxxxxxx>
> > Cc: Brandon Philips <brandon@xxxxxxx>
> > Cc: <stable@xxxxxxxxxxxxxxx>
> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
> > ---
> >  mm/shmem.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/mm/shmem.c b/mm/shmem.c
> > index 47d536e..86c150bf 100644
> > --- a/mm/shmem.c
> > +++ b/mm/shmem.c
> > @@ -2139,7 +2139,7 @@ static long shmem_fallocate(struct file *file, int
> > mode, loff_t offset,
> >  			/* Remove the !PageUptodate pages we added */
> >  			shmem_undo_range(inode,
> >  				(loff_t)start << PAGE_CACHE_SHIFT,
> > -				(loff_t)index << PAGE_CACHE_SHIFT, true);
> > +				((loff_t)index << PAGE_CACHE_SHIFT) - 1,
> > true);
> >  			goto undone;
> >  		}
> > 
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]