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authorQu Wenruo <wqu@suse.com>2023-09-19 05:14:42 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-10-10 22:53:30 +0300
commitd678c078f30268a29237595f573a467ff678356b (patch)
treed28189cfa95513f019b1881314903d259fb0b46d
parenta1f85bc9bc69e7f9146a5f1068c7cc94c6678d27 (diff)
downloadlinux-d678c078f30268a29237595f573a467ff678356b.tar.xz
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 <dan.carpenter@linaro.org> Fixes: f98b6215d7d1 ("btrfs: extent_io: do extra check for extent buffer read write functions") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--fs/btrfs/extent_io.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 0e266772beae..685a375bb6af 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -5634,8 +5634,14 @@ void read_extent_buffer(const struct extent_buffer *eb, void *dstv,
char *dst = (char *)dstv;
unsigned long i = start >> PAGE_SHIFT;
- 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 = offset_in_page(start);