From 41979f2518c28863a8f698c8333c4eefc1e3f7cf Mon Sep 17 00:00:00 2001 From: Wayne Davison Date: Mon, 5 Nov 2007 18:15:04 +0000 Subject: [PATCH] Make sure that get_xattr_data() never tries to malloc 0 bytes. --- xattrs.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/xattrs.c b/xattrs.c index 2345214a..23b5faab 100644 --- a/xattrs.c +++ b/xattrs.c @@ -161,8 +161,11 @@ static char *get_xattr_data(const char *fname, const char *name, size_t *len_ptr int no_missing_error) { size_t datum_len = sys_lgetxattr(fname, name, NULL, 0); + size_t extra_len = *len_ptr; char *ptr; + *len_ptr = datum_len; + if (datum_len == (size_t)-1) { if (errno == ENOTSUP || no_missing_error) return NULL; @@ -172,12 +175,12 @@ static char *get_xattr_data(const char *fname, const char *name, size_t *len_ptr return NULL; } - if (datum_len + *len_ptr < datum_len /* checks for overflow */ - || !(ptr = new_array(char, datum_len + *len_ptr))) + if (!datum_len && !extra_len) + extra_len = 1; /* request non-zero amount of memory */ + if (datum_len + extra_len < datum_len /* checks for overflow */ + || !(ptr = new_array(char, datum_len + extra_len))) out_of_memory("get_xattr_data"); - *len_ptr = datum_len; - if (datum_len) { size_t len = sys_lgetxattr(fname, name, ptr, datum_len); if (len != datum_len) { -- 2.34.1