From d8d2eb7d6b5e48c2bcb0e71a770f8a05375ac03e Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Mon, 11 Oct 2010 17:41:16 +0200 Subject: mailmap: fix use of freed memory On an x86_64 system (F13-based), I ran these commands in an empty directory: git init printf '%s\n' \ ' ' \ 'John ' > .mailmap git shortlog < /dev/null Here's the result: (reading log message from standard input) *** glibc detected *** git: free(): invalid pointer: 0x0000000000f53730 *** ======= Backtrace: ========= /lib64/libc.so.6[0x31ba875676] git[0x48c2a5] git[0x4b9858] ... zsh: abort (core dumped) git shortlog What happened? Some .mailmap entry is of the form, while a subsequent one looks like "User Name , and the two email addresses on the right are not identical but are "equal" when using a case-insensitive comparator. Then, when add_mapping is processing the latter line, new_email is NULL and we free me->email, yet do not replace it with a new strdup'd string. Thus, when later we attempt to use the buffer behind that ->email pointer, we reference freed memory. The solution is to free ->email and ->name only if we're about to replace them. [jc: squashed in the tests from Jonathan] Signed-off-by: Jim Meyering Signed-off-by: Jonathan Nieder Signed-off-by: Junio C Hamano --- mailmap.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'mailmap.c') diff --git a/mailmap.c b/mailmap.c index f80b701292..02fcfde0b0 100644 --- a/mailmap.c +++ b/mailmap.c @@ -79,12 +79,14 @@ static void add_mapping(struct string_list *map, if (old_name == NULL) { debug_mm("mailmap: adding (simple) entry for %s at index %d\n", old_email, index); /* Replace current name and new email for simple entry */ - free(me->name); - free(me->email); - if (new_name) + if (new_name) { + free(me->name); me->name = xstrdup(new_name); - if (new_email) + } + if (new_email) { + free(me->email); me->email = xstrdup(new_email); + } } else { struct mailmap_info *mi = xmalloc(sizeof(struct mailmap_info)); debug_mm("mailmap: adding (complex) entry for %s at index %d\n", old_email, index); -- cgit v1.2.3