diff options
| author | Andreas Gruenbacher <agruenba@redhat.com> | 2021-06-21 22:28:50 +0200 |
|---|---|---|
| committer | Andreas Gruenbacher <agruenba@redhat.com> | 2021-06-28 14:13:38 +0200 |
| commit | d3c51c55cb9274dd43c156f1f26b5eb4d5f2d58c (patch) | |
| tree | 8e94b737f7b6c5cc9ba014cfc7fa8cfa3a3ca1e6 /fs/gfs2 | |
| parent | 38a618dbf47f837f11df01052977dcaf31c5c2a8 (diff) | |
gfs2: Fix underflow in gfs2_page_mkwrite
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>
Diffstat (limited to 'fs/gfs2')
| -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 7b757195fd97..37041873bb95 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -450,8 +450,8 @@ 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; |