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author | Eric Sunshine <sunshine@sunshineco.com> | 2015-05-04 03:25:15 -0400 |
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committer | Junio C Hamano <gitster@pobox.com> | 2015-05-05 10:14:18 -0700 |
commit | 0c3db67cc8137cebea5b1a9c3c7fc379ef8ffda6 (patch) | |
tree | 82a7a5ae13d5bd50f77e5bfbc0d4590b9b0873b6 /builtin | |
parent | git-hash-object.txt: document --literally option (diff) | |
download | tgif-0c3db67cc8137cebea5b1a9c3c7fc379ef8ffda6.tar.xz |
hash-object --literally: fix buffer overrun with extra-long object type
"hash-object" learned in 5ba9a93 (hash-object: add --literally
option, 2014-09-11) to allow crafting a corrupt/broken object of
unknown type.
When the user-provided type is particularly long, however, it can
overflow the relatively small stack-based character array handed to
write_sha1_file_prepare() by hash_sha1_file() and write_sha1_file(),
leading to stack corruption (and crash). Introduce a custom helper
to allow arbitrarily long typenames just for "hash-object --literally".
[jc: Eric's original used a strbuf in the more common codepaths, and
I rewrote it to avoid penalizing the non-literally code. Bugs are mine]
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'builtin')
-rw-r--r-- | builtin/hash-object.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/builtin/hash-object.c b/builtin/hash-object.c index 6158363318..17e8bfdc44 100644 --- a/builtin/hash-object.c +++ b/builtin/hash-object.c @@ -22,10 +22,8 @@ static int hash_literally(unsigned char *sha1, int fd, const char *type, unsigne if (strbuf_read(&buf, fd, 4096) < 0) ret = -1; - else if (flags & HASH_WRITE_OBJECT) - ret = write_sha1_file(buf.buf, buf.len, type, sha1); else - ret = hash_sha1_file(buf.buf, buf.len, type, sha1); + ret = hash_sha1_file_literally(buf.buf, buf.len, type, sha1, flags); strbuf_release(&buf); return ret; } |