[PATCH 2/3] http-push: fix construction of hex value from path
- From
Thomas Gummerer <t.gummerer@gmail.com>
- Date
- Oct 3, 2017, 19:57 UTC
- Message-ID
- <20171003195713.13395-3-t.gummerer@gmail.com>
- In-Reply-To
- <20171003195713.13395-1-t.gummerer@gmail.com>
The get_oid_hex_from_objpath takes care of creating a oid from a pathname. It does this by memcpy'ing the first two bytes of the path to the "hex" string, then skipping the '/', and then copying the rest of the path to the "hex" string. Currently it fails to increase the pointer to the hex string, so the second memcpy invocation just mashes over what was copied in the first one, and leaves the last two bytes in the string uninitialized.
This breaks valgrind in t5540, although the test passes without valgrind:
==5490== Use of uninitialised value of size 8 ==5490== at 0x13C6B5: hexval (cache.h:1238) ==5490== by 0x13C6DB: hex2chr (cache.h:1247) ==5490== by 0x13C734: get_sha1_hex (hex.c:42) ==5490== by 0x13C78E: get_oid_hex (hex.c:53) ==5490== by 0x118BDA: get_oid_hex_from_objpath (http-push.c:1023) ==5490== by 0x118C92: process_ls_object (http-push.c:1038) ==5490== by 0x118E5B: handle_remote_ls_ctx (http-push.c:1077) ==5490== by 0x118227: xml_end_tag (http-push.c:815) ==5490== by 0x50C1448: ??? (in /usr/lib/libexpat.so.1.6.6) ==5490== by 0x50C221B: ??? (in /usr/lib/libexpat.so.1.6.6) ==5490== by 0x50BFBF2: ??? (in /usr/lib/libexpat.so.1.6.6) ==5490== by 0x50C0B24: ??? (in /usr/lib/libexpat.so.1.6.6) ==5490== Uninitialised value was created by a stack allocation ==5490== at 0x118B63: get_oid_hex_from_objpath (http-push.c:1012) ==5490==
Fix this by correctly incrementing the pointer to the "hex" variable, so the first two bytes are left untouched by the memcpy call, and the last two bytes are correctly initialized.
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com> --- http-push.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/http-push.c b/http-push.c index e4c9b065ce..e9a01ec4da 100644 --- a/http-push.c +++ b/http-push.c @@ -1018,7 +1018,7 @@ static int get_oid_hex_from_objpath(const char *path, struct object_id *oid) memcpy(hex, path, 2); path += 2; path++; /* skip '/' */ - memcpy(hex, path, GIT_SHA1_HEXSZ - 2); + memcpy(hex + 2, path, GIT_SHA1_HEXSZ - 2); return get_oid_hex(hex, oid); }
-- 2.14.1.480.gb18f417b89