diff options
| author | Filipe Manana <fdmanana@suse.com> | 2024-07-04 16:11:20 +0100 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2024-07-11 16:32:22 +0200 |
| commit | 8e7860543a94784d744c7ce34b78a2e11beefa5c (patch) | |
| tree | 9fd6c89883a59adce50cf5604e6a33520c30dd47 /fs | |
| parent | 320d8dc612660da84c3b70a28658bb38069e5a9a (diff) | |
btrfs: fix extent map use-after-free when adding pages to compressed bio
At add_ra_bio_pages() we are accessing the extent map to calculate
'add_size' after we dropped our reference on the extent map, resulting
in a use-after-free. Fix this by computing 'add_size' before dropping our
extent map reference.
Reported-by: syzbot+853d80cba98ce1157ae6@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/000000000000038144061c6d18f2@google.com/
Fixes: 6a4049102055 ("btrfs: subpage: make add_ra_bio_pages() compatible")
CC: stable@vger.kernel.org # 6.1+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/compression.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index a149f3659b15..a8e2c461aff7 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -515,6 +515,7 @@ static noinline int add_ra_bio_pages(struct inode *inode, put_page(page); break; } + add_size = min(em->start + em->len, page_end + 1) - cur; free_extent_map(em); if (page->index == end_index) { @@ -527,7 +528,6 @@ static noinline int add_ra_bio_pages(struct inode *inode, } } - add_size = min(em->start + em->len, page_end + 1) - cur; ret = bio_add_page(orig_bio, page, add_size, offset_in_page(cur)); if (ret != add_size) { unlock_extent(tree, cur, page_end, NULL); |