diff options
| author | Jan Kara <jack@suse.cz> | 2017-05-25 11:46:22 -0400 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-12-31 02:51:24 +0100 |
| commit | e5983e9c4e1c61b347aeda7243266bee387a40e1 (patch) | |
| tree | bac38b73898ee8585cc06881421622dee6f1c6a7 /kernel/capability.c | |
| parent | a1bac3c7c00397f50a3479c26fe1bd760bea7fc9 (diff) | |
ext4: Fix data corruption for mmap writes
mpage_submit_page() can race with another process growing i_size and
writing data via mmap to the written-back page. As mpage_submit_page()
samples i_size too early, it may happen that ext4_bio_write_page()
zeroes out too large tail of the page and thus corrupts user data.
Fix the problem by sampling i_size only after the page has been
write-protected in page tables by clear_page_dirty_for_io() call.
Reported-by: Michael Zimmer <michael@swarm64.com>
CC: stable@vger.kernel.org
Fixes: cb20d5188366f04d96d2e07b1240cc92170ade40
Signed-off-by: Jan Kara <jack@suse.cz>
[@nathanchance: fixed conflicts]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Joe Maples <joe@frap129.org>
Diffstat (limited to 'kernel/capability.c')
0 files changed, 0 insertions, 0 deletions