diff options
Diffstat (limited to 'fs/iomap.c')
| -rw-r--r-- | fs/iomap.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/fs/iomap.c b/fs/iomap.c index 4966abd956d4..64e07534ded3 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -941,7 +941,14 @@ iomap_dio_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) @@ -1046,8 +1053,15 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, } pos += ret; - if (iov_iter_rw(iter) == READ && pos >= dio->i_size) + if (iov_iter_rw(iter) == READ && pos >= dio->i_size) { + /* + * We only report that we've read data up to i_size. + * Revert iter to a state corresponding to that as + * some callers (such as splice code) rely on it. + */ + iov_iter_revert(iter, pos - dio->i_size); break; + } } while ((count = iov_iter_count(iter)) > 0); blk_finish_plug(&plug); |