From: Dave Chinner dchinner@redhat.com
[ Upstream commit cb512c921639613ce03f87e62c5e93ed9fe8c84d ]
When we first allocate or resize an inline inode fork, we round up the allocation to 4 byte alingment to make journal alignment constraints. We don't clear the unused bytes, so we can copy up to three uninitialised bytes into the journal. Zero those bytes so we only ever copy zeros into the journal.
Signed-off-by: Dave Chinner dchinner@redhat.com Reviewed-by: Darrick J. Wong djwong@kernel.org Reviewed-by: Allison Henderson allison.henderson@oracle.com Signed-off-by: Dave Chinner david@fromorbit.com Signed-off-by: Leah Rumancik leah.rumancik@gmail.com Acked-by: Darrick J. Wong djwong@kernel.org --- fs/xfs/libxfs/xfs_inode_fork.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c index 1d174909f9bd..20095233d7bc 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.c +++ b/fs/xfs/libxfs/xfs_inode_fork.c @@ -50,8 +50,13 @@ xfs_init_local_fork( mem_size++;
if (size) { + /* + * As we round up the allocation here, we need to ensure the + * bytes we don't copy data into are zeroed because the log + * vectors still copy them into the journal. + */ real_size = roundup(mem_size, 4); - ifp->if_u1.if_data = kmem_alloc(real_size, KM_NOFS); + ifp->if_u1.if_data = kmem_zalloc(real_size, KM_NOFS); memcpy(ifp->if_u1.if_data, data, size); if (zero_terminate) ifp->if_u1.if_data[size] = '\0'; @@ -500,10 +505,11 @@ xfs_idata_realloc( /* * For inline data, the underlying buffer must be a multiple of 4 bytes * in size so that it can be logged and stay on word boundaries. - * We enforce that here. + * We enforce that here, and use __GFP_ZERO to ensure that size + * extensions always zero the unused roundup area. */ ifp->if_u1.if_data = krealloc(ifp->if_u1.if_data, roundup(new_size, 4), - GFP_NOFS | __GFP_NOFAIL); + GFP_NOFS | __GFP_NOFAIL | __GFP_ZERO); ifp->if_bytes = new_size; }