diff options
| -rw-r--r-- | fs/iomap.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/iomap.c b/fs/iomap.c index 72f3864a2e6b..77c214194edf 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -1677,7 +1677,14 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, dio->submit.cookie = submit_bio(bio); } while (nr_pages); - if (need_zeroout) { + /* + * We need to zeroout the tail of a sub-block write if the extent type + * requires zeroing or the write extends beyond EOF. If we don't zero + * the block tail in the latter case, we can expose stale data via mmap + * reads of the EOF block. + */ + if (need_zeroout || + ((dio->flags & IOMAP_DIO_WRITE) && pos >= i_size_read(inode))) { /* zero out from the end of the write to the end of the block */ pad = pos & (fs_block_size - 1); if (pad) |