From: zhanghailiang <zhang.zhanghailiang@huawei.com>
To: qemu-devel@nongnu.org
Cc: mdroth@linux.vnet.ibm.com, armbru@redhat.com,
luonengjun@huawei.com, peter.huangpeng@huawei.com,
qemu-stable@nongnu.org, lcapitulino@redhat.com,
zhanghailiang <zhang.zhanghailiang@huawei.com>
Subject: [Qemu-devel] [PATCH v2] qga: Rewrite code where using readdir_r
Date: Fri, 19 Sep 2014 11:09:10 +0800 [thread overview]
Message-ID: <1411096150-3044-1-git-send-email-zhang.zhanghailiang@huawei.com> (raw)
If readdir_r fails, error_setg_errno will reference the freed
pointer *dirpath*.
Moreover, readdir_r may cause a buffer overflow, using readdir instead.
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
---
v2:
- Switch readdir_r to readdir (Comment of Eric Blake)
---
qga/commands-posix.c | 27 +++++++++++++++------------
1 file changed, 15 insertions(+), 12 deletions(-)
diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 7eed7f4..f6f3e3c 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -956,7 +956,7 @@ static void build_guest_fsinfo_for_virtual_device(char const *syspath,
{
DIR *dir;
char *dirpath;
- struct dirent entry, *result;
+ struct dirent *entry;
dirpath = g_strdup_printf("%s/slaves", syspath);
dir = opendir(dirpath);
@@ -965,22 +965,24 @@ static void build_guest_fsinfo_for_virtual_device(char const *syspath,
g_free(dirpath);
return;
}
- g_free(dirpath);
for (;;) {
- if (readdir_r(dir, &entry, &result) != 0) {
- error_setg_errno(errp, errno, "readdir_r(\"%s\")", dirpath);
- break;
- }
- if (!result) {
+ errno = 0;
+ entry = readdir(dir);
+ if (entry == NULL) {
+ if (errno) {
+ error_setg_errno(errp, errno, "readdir(\"%s\")", dirpath);
+ }
break;
}
- if (entry.d_type == DT_LNK) {
- g_debug(" slave device '%s'", entry.d_name);
- dirpath = g_strdup_printf("%s/slaves/%s", syspath, entry.d_name);
- build_guest_fsinfo_for_device(dirpath, fs, errp);
- g_free(dirpath);
+ if (entry->d_type == DT_LNK) {
+ char *path;
+
+ g_debug(" slave device '%s'", entry->d_name);
+ path = g_strdup_printf("%s/slaves/%s", syspath, entry->d_name);
+ build_guest_fsinfo_for_device(path, fs, errp);
+ g_free(path);
if (*errp) {
break;
@@ -988,6 +990,7 @@ static void build_guest_fsinfo_for_virtual_device(char const *syspath,
}
}
+ g_free(dirpath);
closedir(dir);
}
--
1.7.12.4
next reply other threads:[~2014-09-19 3:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-19 3:09 zhanghailiang [this message]
2014-09-26 8:32 ` [Qemu-devel] [PATCH v2] qga: Rewrite code where using readdir_r zhanghailiang
2014-09-26 15:40 ` Paolo Bonzini
2014-09-28 6:06 ` zhanghailiang
2014-09-26 15:45 ` Eric Blake
2014-10-01 17:47 ` Michael Roth
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