# [PATCH] path: use xmalloc in add_to_trie 3 messages from 2017-10-24 to 2017-10-24. Participants: Andrey Okoshkin, Stefan Beller, Jeff King. Thread: https://gitlist.dev/t/47019 ## Andrey Okoshkin, 2017-10-24 15:15 Subject: [PATCH] path: use xmalloc in add_to_trie Message-ID: URL: https://gitlist.dev/e/e63c2208-900e-138a-a13c-fecf9403e0b8%40samsung.com In-Reply-To: ``` Add usage of xmalloc() instead of malloc() in add_to_trie() as xmalloc wraps and checks memory allocation result. Signed-off-by: Andrey Okoshkin --- Hello, I'm not sure but it looks like there is a missing check of the malloc result. memcpy() may crash with SIGSEGV due to the memory allocation failure. make_trie_node() uses xmalloc() and xcalloc() - so I believe add_to_trie() also should use it. Best regards, Andrey path.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/path.c b/path.c index 335d4dd87..69b23ef17 100644 --- a/path.c +++ b/path.c @@ -191,7 +191,7 @@ static void *add_to_trie(struct trie *root, const char *key, void *value) * Split this node: child will contain this node's * existing children. */ - child = malloc(sizeof(*child)); + child = xmalloc(sizeof(*child)); memcpy(child->children, root->children, sizeof(root->children)); child->len = root->len - i - 1; -- 2.14.3 ``` ## Stefan Beller, 2017-10-24 16:13 Subject: Re: [PATCH] path: use xmalloc in add_to_trie Message-ID: URL: https://gitlist.dev/e/CAGZ79kZM_hVi8BeTmL5u_QK5%2B%3D1g3gcPsccEe1AJVpDLUWz_9Q%40mail.gmail.com In-Reply-To: ``` On Tue, Oct 24, 2017 at 8:15 AM, Andrey Okoshkin wrote: > Add usage of xmalloc() instead of malloc() in add_to_trie() as xmalloc wraps > and checks memory allocation result. > > Signed-off-by: Andrey Okoshkin > --- > Hello, > I'm not sure but it looks like there is a missing check of the malloc result. > memcpy() may crash with SIGSEGV due to the memory allocation failure. > make_trie_node() uses xmalloc() and xcalloc() - so I believe add_to_trie() > also should use it. Good catch! Thanks for spotting. Trying to find similar occurrences via git grep "= malloc" did not yield other places that need the same fix. Thanks, Stefan ``` ## Jeff King, 2017-10-24 19:26 Subject: Re: [PATCH] path: use xmalloc in add_to_trie Message-ID: <20171024192658.4rvxvb34y64lt2tc@sigill.intra.peff.net> URL: https://gitlist.dev/e/20171024192658.4rvxvb34y64lt2tc%40sigill.intra.peff.net In-Reply-To: ``` On Tue, Oct 24, 2017 at 09:13:28AM -0700, Stefan Beller wrote: > On Tue, Oct 24, 2017 at 8:15 AM, Andrey Okoshkin wrote: > > Add usage of xmalloc() instead of malloc() in add_to_trie() as xmalloc wraps > > and checks memory allocation result. > > > > Signed-off-by: Andrey Okoshkin > > --- > > Hello, > > I'm not sure but it looks like there is a missing check of the malloc result. > > memcpy() may crash with SIGSEGV due to the memory allocation failure. > > make_trie_node() uses xmalloc() and xcalloc() - so I believe add_to_trie() > > also should use it. > > Good catch! Thanks for spotting. > > Trying to find similar occurrences via git grep "= malloc" did not > yield other places that need the same fix. Don't forget realloc and calloc (though I don't think there are any cases that need touching there; just a hint for anybody doing auditing). -Peff ```