diff options
| author | Andreas Gruenbacher <agruenba@redhat.com> | 2021-06-21 22:28:50 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-14 16:55:38 +0200 |
| commit | 3ae1c663bdeb4cb82c557478358527ddacd516d8 (patch) | |
| tree | 56d29e656c8d8fd856584f0e69c3f0b5020246c7 | |
| parent | b242ae99fac6f57e39d7143d89d996fedb4ed7f6 (diff) | |
gfs2: Fix underflow in gfs2_page_mkwrite
commit d3c51c55cb9274dd43c156f1f26b5eb4d5f2d58c upstream.
On filesystems with a block size smaller than PAGE_SIZE and non-empty
files smaller then PAGE_SIZE, gfs2_page_mkwrite could end up allocating
excess blocks beyond the end of the file, similar to fallocate. This
doesn't make sense; fix it.
Reported-by: Bob Peterson <rpeterso@redhat.com>
Fixes: 184b4e60853d ("gfs2: Fix end-of-file handling in gfs2_page_mkwrite")
Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/gfs2/file.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index 16fb0184ce5e..cfd9d03f604f 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -474,8 +474,8 @@ static vm_fault_t gfs2_page_mkwrite(struct vm_fault *vmf) file_update_time(vmf->vma->vm_file); /* page is wholly or partially inside EOF */ - if (offset > size - PAGE_SIZE) - length = offset_in_page(size); + if (size - offset < PAGE_SIZE) + length = size - offset; else length = PAGE_SIZE; |