From: Qu Wenruo Date: Tue, 19 Sep 2023 02:14:42 +0000 (+0930) Subject: btrfs: reset destination buffer when read_extent_buffer() gets invalid range X-Git-Tag: v6.1.61~730 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=cca10592ffd5e1abfe9479b4b056e81fb9872330;p=platform%2Fkernel%2Flinux-starfive.git btrfs: reset destination buffer when read_extent_buffer() gets invalid range [ Upstream commit 74ee79142c0a344d4eae2eb7012ebc4e82254109 ] Commit f98b6215d7d1 ("btrfs: extent_io: do extra check for extent buffer read write functions") changed how we handle invalid extent buffer range for read_extent_buffer(). Previously if the range is invalid we just set the destination to zero, but after the patch we do nothing and error out. This can lead to smatch static checker errors like: fs/btrfs/print-tree.c:186 print_uuid_item() error: uninitialized symbol 'subvol_id'. fs/btrfs/tests/extent-io-tests.c:338 check_eb_bitmap() error: uninitialized symbol 'has'. fs/btrfs/tests/extent-io-tests.c:353 check_eb_bitmap() error: uninitialized symbol 'has'. fs/btrfs/uuid-tree.c:203 btrfs_uuid_tree_remove() error: uninitialized symbol 'read_subid'. fs/btrfs/uuid-tree.c:353 btrfs_uuid_tree_iterate() error: uninitialized symbol 'subid_le'. fs/btrfs/uuid-tree.c:72 btrfs_uuid_tree_lookup() error: uninitialized symbol 'data'. fs/btrfs/volumes.c:7415 btrfs_dev_stats_value() error: uninitialized symbol 'val'. Fix those warnings by reverting back to the old memset() behavior. By this we keep the static checker happy and would still make a lot of noise when such invalid ranges are passed in. Reported-by: Dan Carpenter Fixes: f98b6215d7d1 ("btrfs: extent_io: do extra check for extent buffer read write functions") Signed-off-by: Qu Wenruo Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 0ad6904..afcc96a 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5184,8 +5184,14 @@ void read_extent_buffer(const struct extent_buffer *eb, void *dstv, char *dst = (char *)dstv; unsigned long i = get_eb_page_index(start); - if (check_eb_range(eb, start, len)) + if (check_eb_range(eb, start, len)) { + /* + * Invalid range hit, reset the memory, so callers won't get + * some random garbage for their uninitialzed memory. + */ + memset(dstv, 0, len); return; + } offset = get_eb_offset_in_page(eb, start);