From aa9f618909d30e3f0c7181243e89a81220507e6e Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Fri, 23 Feb 2024 08:34:23 +0000 Subject: [PATCH] Always check `parse_tree*()`'s return value Otherwise we may easily run into serious crashes: For example, if we run `init_tree_desc()` directly after a failed `parse_tree()`, we are accessing uninitialized data or trying to dereference `NULL`. Note that the `parse_tree()` function already takes care of showing an error message. The `parse_tree_indirectly()` and `repo_get_commit_tree()` functions do not, therefore those latter call sites need to show a useful error message while the former do not. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- builtin/checkout.c | 19 ++++++++++++++++--- builtin/clone.c | 3 ++- builtin/commit.c | 3 ++- builtin/merge-tree.c | 6 ++++++ builtin/read-tree.c | 3 ++- builtin/reset.c | 4 ++++ cache-tree.c | 4 ++-- merge-ort.c | 3 +++ merge-recursive.c | 3 ++- merge.c | 5 ++++- reset.c | 5 +++++ sequencer.c | 4 ++++ 12 files changed, 52 insertions(+), 10 deletions(-) diff --git a/builtin/checkout.c b/builtin/checkout.c index f02434bc15..9ab0901d62 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -707,7 +707,8 @@ static int reset_tree(struct tree *tree, const struct checkout_opts *o, init_checkout_metadata(&opts.meta, info->refname, info->commit ? &info->commit->object.oid : null_oid(), NULL); - parse_tree(tree); + if (parse_tree(tree) < 0) + return 128; init_tree_desc(&tree_desc, tree->buffer, tree->size); switch (unpack_trees(1, &tree_desc, &opts)) { case -2: @@ -786,9 +787,15 @@ static int merge_working_tree(const struct checkout_opts *opts, if (new_branch_info->commit) BUG("'switch --orphan' should never accept a commit as starting point"); new_tree = parse_tree_indirect(the_hash_algo->empty_tree); - } else + if (!new_tree) + BUG("unable to read empty tree"); + } else { new_tree = repo_get_commit_tree(the_repository, new_branch_info->commit); + if (!new_tree) + return error(_("unable to read tree (%s)"), + oid_to_hex(&new_branch_info->commit->object.oid)); + } if (opts->discard_changes) { ret = reset_tree(new_tree, opts, 1, writeout_error, new_branch_info); if (ret) @@ -823,7 +830,8 @@ static int merge_working_tree(const struct checkout_opts *opts, oid_to_hex(old_commit_oid)); init_tree_desc(&trees[0], tree->buffer, tree->size); - parse_tree(new_tree); + if (parse_tree(new_tree) < 0) + exit(128); tree = new_tree; init_tree_desc(&trees[1], tree->buffer, tree->size); @@ -1239,10 +1247,15 @@ static void setup_new_branch_info_and_source_tree( if (!new_branch_info->commit) { /* not a commit */ *source_tree = parse_tree_indirect(rev); + if (!*source_tree) + die(_("unable to read tree (%s)"), oid_to_hex(rev)); } else { parse_commit_or_die(new_branch_info->commit); *source_tree = repo_get_commit_tree(the_repository, new_branch_info->commit); + if (!*source_tree) + die(_("unable to read tree (%s)"), + oid_to_hex(&new_branch_info->commit->object.oid)); } } diff --git a/builtin/clone.c b/builtin/clone.c index c6357af949..4410b55be9 100644 --- a/builtin/clone.c +++ b/builtin/clone.c @@ -736,7 +736,8 @@ static int checkout(int submodule_progress, int filter_submodules) tree = parse_tree_indirect(&oid); if (!tree) die(_("unable to parse commit %s"), oid_to_hex(&oid)); - parse_tree(tree); + if (parse_tree(tree) < 0) + exit(128); init_tree_desc(&t, tree->buffer, tree->size); if (unpack_trees(1, &t, &opts) < 0) die(_("unable to checkout working tree")); diff --git a/builtin/commit.c b/builtin/commit.c index 781af2e206..0723f06de7 100644 --- a/builtin/commit.c +++ b/builtin/commit.c @@ -339,7 +339,8 @@ static void create_base_index(const struct commit *current_head) tree = parse_tree_indirect(¤t_head->object.oid); if (!tree) die(_("failed to unpack HEAD tree object")); - parse_tree(tree); + if (parse_tree(tree) < 0) + exit(128); init_tree_desc(&t, tree->buffer, tree->size); if (unpack_trees(1, &t, &opts)) exit(128); /* We've already reported the error, finish dying */ diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c index 2d4ce5b388..3492a575a6 100644 --- a/builtin/merge-tree.c +++ b/builtin/merge-tree.c @@ -447,12 +447,18 @@ static int real_merge(struct merge_tree_options *o, if (repo_get_oid_treeish(the_repository, merge_base, &base_oid)) die(_("could not parse as tree '%s'"), merge_base); base_tree = parse_tree_indirect(&base_oid); + if (!base_tree) + die(_("unable to read tree (%s)"), oid_to_hex(&base_oid)); if (repo_get_oid_treeish(the_repository, branch1, &head_oid)) die(_("could not parse as tree '%s'"), branch1); parent1_tree = parse_tree_indirect(&head_oid); + if (!parent1_tree) + die(_("unable to read tree (%s)"), oid_to_hex(&head_oid)); if (repo_get_oid_treeish(the_repository, branch2, &merge_oid)) die(_("could not parse as tree '%s'"), branch2); parent2_tree = parse_tree_indirect(&merge_oid); + if (!parent2_tree) + die(_("unable to read tree (%s)"), oid_to_hex(&merge_oid)); opt.ancestor = merge_base; merge_incore_nonrecursive(&opt, base_tree, parent1_tree, parent2_tree, &result); diff --git a/builtin/read-tree.c b/builtin/read-tree.c index 8196ca9dd8..5923ed3689 100644 --- a/builtin/read-tree.c +++ b/builtin/read-tree.c @@ -263,7 +263,8 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix) cache_tree_free(&the_index.cache_tree); for (i = 0; i < nr_trees; i++) { struct tree *tree = trees[i]; - parse_tree(tree); + if (parse_tree(tree) < 0) + return 128; init_tree_desc(t+i, tree->buffer, tree->size); } if (unpack_trees(nr_trees, t, &opts)) diff --git a/builtin/reset.c b/builtin/reset.c index 4b018d20e3..fd36fc5bd9 100644 --- a/builtin/reset.c +++ b/builtin/reset.c @@ -119,6 +119,10 @@ static int reset_index(const char *ref, const struct object_id *oid, int reset_t if (reset_type == MIXED || reset_type == HARD) { tree = parse_tree_indirect(oid); + if (!tree) { + error(_("unable to read tree (%s)"), oid_to_hex(oid)); + goto out; + } prime_cache_tree(the_repository, the_repository->index, tree); } diff --git a/cache-tree.c b/cache-tree.c index 641427ed41..c6508b64a5 100644 --- a/cache-tree.c +++ b/cache-tree.c @@ -779,8 +779,8 @@ static void prime_cache_tree_rec(struct repository *r, struct cache_tree_sub *sub; struct tree *subtree = lookup_tree(r, &entry.oid); - if (!subtree->object.parsed) - parse_tree(subtree); + if (!subtree->object.parsed && parse_tree(subtree) < 0) + exit(128); sub = cache_tree_sub(it, entry.path); sub->cache_tree = cache_tree(); diff --git a/merge-ort.c b/merge-ort.c index 79d9e18f63..910ba38ff0 100644 --- a/merge-ort.c +++ b/merge-ort.c @@ -4983,6 +4983,9 @@ redo: if (result->clean >= 0) { result->tree = parse_tree_indirect(&working_tree_oid); + if (!result->tree) + die(_("unable to read tree (%s)"), + oid_to_hex(&working_tree_oid)); /* existence of conflicted entries implies unclean */ result->clean &= strmap_empty(&opt->priv->conflicted); } diff --git a/merge-recursive.c b/merge-recursive.c index e3beb0801b..10d41bfd48 100644 --- a/merge-recursive.c +++ b/merge-recursive.c @@ -410,7 +410,8 @@ static inline int merge_detect_rename(struct merge_options *opt) static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree) { - parse_tree(tree); + if (parse_tree(tree) < 0) + exit(128); init_tree_desc(desc, tree->buffer, tree->size); } diff --git a/merge.c b/merge.c index b60925459c..14a7325859 100644 --- a/merge.c +++ b/merge.c @@ -80,7 +80,10 @@ int checkout_fast_forward(struct repository *r, return -1; } for (i = 0; i < nr_trees; i++) { - parse_tree(trees[i]); + if (parse_tree(trees[i]) < 0) { + rollback_lock_file(&lock_file); + return -1; + } init_tree_desc(t+i, trees[i]->buffer, trees[i]->size); } diff --git a/reset.c b/reset.c index 48da0adf85..080bcb6d65 100644 --- a/reset.c +++ b/reset.c @@ -158,6 +158,11 @@ int reset_head(struct repository *r, const struct reset_head_opts *opts) } tree = parse_tree_indirect(oid); + if (!tree) { + ret = error(_("unable to read tree (%s)"), oid_to_hex(oid)); + goto leave_reset_head; + } + prime_cache_tree(r, r->index, tree); if (write_locked_index(r->index, &lock, COMMIT_LOCK) < 0) { diff --git a/sequencer.c b/sequencer.c index d584cac8ed..33d12b2ffd 100644 --- a/sequencer.c +++ b/sequencer.c @@ -715,6 +715,8 @@ static int do_recursive_merge(struct repository *r, o.show_rename_progress = 1; head_tree = parse_tree_indirect(head); + if (!head_tree) + return error(_("unable to read tree (%s)"), oid_to_hex(head)); next_tree = next ? repo_get_commit_tree(r, next) : empty_tree(r); base_tree = base ? repo_get_commit_tree(r, base) : empty_tree(r); @@ -3887,6 +3889,8 @@ static int do_reset(struct repository *r, } tree = parse_tree_indirect(&oid); + if (!tree) + return error(_("unable to read tree (%s)"), oid_to_hex(&oid)); prime_cache_tree(r, r->index, tree); if (write_locked_index(r->index, &lock, COMMIT_LOCK) < 0)