undef/git-commit-vandalism
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

fsck: actually detect bad file modes in trees

Browse Source 
We use the normal tree_desc code to iterate over trees in fsck, meaning
we only see the canonicalized modes it returns. And hence we'd never see
anything unexpected, since it will coerce literally any garbage into one
of our normal and accepted modes.

We can use the new RAW_MODES flag to see the real modes, and then use
the existing code to actually analyze them. The existing code is written
as allow-known-good, so there's not much point in testing a variety of
breakages. The one tested here should be S_IFREG but with nonsense
permissions.

Do note that the error-reporting here isn't great. We don't mention the
specific bad mode, but just that the tree has one or more broken modes.
But when you go to look at it with "git ls-tree", we'll report the
canonicalized mode! This isn't ideal, but given that this should come up
rarely, and that any number of other tree corruptions might force you
into looking at the binary bytes via "cat-file", it's not the end of the
world. And it's something we can improve on top later if we choose.

Reported-by: Xavier Morel <xavier.morel@masklinn.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King 2022-08-10 17:02:45 -04:00 committed by Junio C Hamano
parent ec18b10bf2
commit 53602a937d
2 changed files with 15 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
fsck.c
View File

@ -578,7 +578,7 @@ static int fsck_tree(const struct object_id *tree_oid,
const char *o_name;
struct name_stack df_dup_candidates = { NULL };
if (init_tree_desc_gently(&desc, buffer, size, 0)) {
if (init_tree_desc_gently(&desc, buffer, size, TREE_DESC_RAW_MODES)) {
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_BAD_TREE,
"cannot be parsed as a tree");

14
t/t1450-fsck.sh
View File

@ -364,6 +364,20 @@ test_expect_success 'tree entry with type mismatch' '
test_i18ngrep ! "dangling blob" out
'
test_expect_success 'tree entry with bogus mode' '
test_when_finished "remove_object \$blob" &&
test_when_finished "remove_object \$tree" &&
blob=$(echo blob | git hash-object -w --stdin) &&
blob_oct=$(echo $blob | hex2oct) &&
tree=$(printf "100000 foo\0${blob_oct}" |
git hash-object -t tree --stdin -w --literally) &&
git fsck 2>err &&
cat >expect <<-EOF &&
warning in tree $tree: badFilemode: contains bad file modes
EOF
test_cmp expect err
'
test_expect_success 'tag pointing to nonexistent' '
badoid=$(test_oid deadbeef) &&
cat >invalid-tag <<-EOF &&