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author | Taylor Blau <me@ttaylorr.com> | 2019-09-05 18:04:57 -0400 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2019-09-09 10:55:59 -0700 |
commit | 806278dead57766bf000af62dcb8892ee3a24956 (patch) | |
tree | b8b3c92ff86935c84553f5f1d035d881df65cac6 /commit.c | |
parent | commit-graph.c: handle commit parsing errors (diff) | |
download | tgif-806278dead57766bf000af62dcb8892ee3a24956.tar.xz |
commit-graph.c: handle corrupt/missing trees
Apply similar treatment as in the previous commit to handle an unchecked
call to 'get_commit_tree_oid()'. Previously, a NULL return value from
this function would be immediately dereferenced with '->hash', and then
cause a segfault.
Before dereferencing to access the 'hash' member, check the return value
of 'get_commit_tree_oid()' to make sure that it is not NULL.
To make this check correct, a related change is also needed in
'commit.c', which is to check the return value of 'get_commit_tree'
before taking its address. If 'get_commit_tree' returns NULL, we
encounter an undefined behavior when taking the address of the return
value of 'get_commit_tree' and then taking '->object.oid'. (On my system,
this is memory address 0x8, which is obviously wrong).
Fix this by making sure that 'get_commit_tree' returns something
non-NULL before digging through a structure that is not there, thus
preventing a segfault down the line in the commit graph code.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'commit.c')
-rw-r--r-- | commit.c | 3 |
1 files changed, 2 insertions, 1 deletions
@@ -358,7 +358,8 @@ struct tree *repo_get_commit_tree(struct repository *r, struct object_id *get_commit_tree_oid(const struct commit *commit) { - return &get_commit_tree(commit)->object.oid; + struct tree *tree = get_commit_tree(commit); + return tree ? &tree->object.oid : NULL; } void release_commit_memory(struct parsed_object_pool *pool, struct commit *c) |