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| author | Kees Cook <keescook@chromium.org> | 2018-08-17 15:44:07 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-17 16:20:27 -0700 |
| commit | ac4ecf968acb9e54c335f99d842d56d6b90e28fb (patch) | |
| tree | bfbd2cc93a3d3e1e8de4f2f6df6a248252a8fb9e | |
| parent | a10dcebacdb0cf6eb29c211e99cf190cd131a16a (diff) | |
| download | lwn-ac4ecf968acb9e54c335f99d842d56d6b90e28fb.tar.gz lwn-ac4ecf968acb9e54c335f99d842d56d6b90e28fb.zip | |
ntfs: aops: remove VLA usage
In the quest to remove all stack VLA usage from the kernel[1], this uses
the maximum size needed on the stack and adds a sanity check for
robustness: index.block_size cannot be larger than PAGE_SIZE nor less
than NTFS_BLOCK_SIZE.
[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com
Link: http://lkml.kernel.org/r/20180626172909.41453-2-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Anton Altaparmakov <anton@tuxera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/ntfs/aops.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c index 01c770979921..8946130c87ad 100644 --- a/fs/ntfs/aops.c +++ b/fs/ntfs/aops.c @@ -922,7 +922,7 @@ static int ntfs_write_mst_block(struct page *page, ntfs_volume *vol = ni->vol; u8 *kaddr; unsigned int rec_size = ni->itype.index.block_size; - ntfs_inode *locked_nis[PAGE_SIZE / rec_size]; + ntfs_inode *locked_nis[PAGE_SIZE / NTFS_BLOCK_SIZE]; struct buffer_head *bh, *head, *tbh, *rec_start_bh; struct buffer_head *bhs[MAX_BUF_PER_PAGE]; runlist_element *rl; @@ -931,6 +931,9 @@ static int ntfs_write_mst_block(struct page *page, bool sync, is_mft, page_is_dirty, rec_is_dirty; unsigned char bh_size_bits; + if (WARN_ON(rec_size < NTFS_BLOCK_SIZE)) + return -EINVAL; + ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index " "0x%lx.", vi->i_ino, ni->type, page->index); BUG_ON(!NInoNonResident(ni)); |