From 6c524781cef0e6b00f4602da4ac7a4e03891997c Mon Sep 17 00:00:00 2001
From: Jiffin Tony Thottan <jthottan@redhat.com>
Date: Fri, 10 Jul 2015 23:12:28 +0530
Subject: [PATCH 234/234] features/posix : Avoid double free of a variable in posix_setxattr()
The buffer acl_xattr is introduced in posix_setxattr() as part of
http://review.gluster.org/#/c/11519/. This variable can be freed
twice in the code path , one in dict_unref() and another by explicit
GF_FREE() call in the code. This patch avoids the same.
Backport of http://review.gluster.org/#/c/11627/
Upstream reference
>Change-Id: I31c6384e37ab8d8baaed7a53de668c2eb5d82338
>BUG: 1242030
>Signed-off-by: Jiffin Tony Thottan <jthottan@redhat.com>
Change-Id: I4c4156575602a9a5c41a34cfc8f92e1e249538ea
BUG: 1241839
Signed-off-by: Jiffin Tony Thottan <jthottan@redhat.com>
Reviewed-on: https://code.engineering.redhat.com/gerrit/52816
Reviewed-by: Kaleb Keithley <kkeithle@redhat.com>
Tested-by: Kaleb Keithley <kkeithle@redhat.com>
---
xlators/storage/posix/src/posix.c | 48 ++++++++++++++++++------------------
1 files changed, 24 insertions(+), 24 deletions(-)
diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index 27c3457..58f68eb 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -3322,10 +3322,8 @@ posix_setxattr (call_frame_t *frame, xlator_t *this,
* reduced into required size using GF_REALLO().
*/
acl_xattr = GF_CALLOC (1, ACL_BUFFER_MAX, gf_posix_mt_char);
- if (!acl_xattr) {
- ret = -1;
+ if (!acl_xattr)
goto out;
- }
acl_size = sys_lgetxattr (real_path, POSIX_ACL_ACCESS_XATTR,
acl_xattr, ACL_BUFFER_MAX);
@@ -3334,7 +3332,6 @@ posix_setxattr (call_frame_t *frame, xlator_t *this,
gf_msg (this->name, GF_LOG_WARNING, errno,
P_MSG_XATTR_FAILED, "Posix acl is not set "
"properly at the backend");
- ret = -1;
goto out;
}
@@ -3343,32 +3340,33 @@ posix_setxattr (call_frame_t *frame, xlator_t *this,
gf_msg (this->name, GF_LOG_WARNING, ENOMEM,
P_MSG_BUFFER_OVERFLOW, "size of acl is more"
"than the buffer");
- ret = -1;
goto out;
}
acl_xattr = GF_REALLOC (acl_xattr, acl_size);
+ if (!acl_xattr)
+ goto out;
+
ret = dict_set_bin (xattr, POSIX_ACL_ACCESS_XATTR,
acl_xattr, acl_size);
- if (ret) {
+ if (ret)
gf_msg (this->name, GF_LOG_WARNING, 0,
P_MSG_SET_XDATA_FAIL, "failed to set"
"xdata for acl");
- ret = -1;
- goto out;
- }
- }
- GF_FREE (acl_xattr);
- acl_xattr = NULL;
+ /*
+ * dict_unref() will call GF_FREE() indirectly, so to avoid
+ * double freeing acl_xattr in out, just set it as NULL here
+ */
+ acl_xattr = NULL;
+ }
if (dict_get (dict, GF_POSIX_ACL_DEFAULT)) {
acl_xattr = GF_CALLOC (1, ACL_BUFFER_MAX, gf_posix_mt_char);
- if (!acl_xattr) {
- ret = -1;
+ if (!acl_xattr)
goto out;
- }
+
acl_size = sys_lgetxattr (real_path, POSIX_ACL_DEFAULT_XATTR,
acl_xattr, ACL_BUFFER_MAX);
@@ -3376,7 +3374,6 @@ posix_setxattr (call_frame_t *frame, xlator_t *this,
gf_msg (this->name, GF_LOG_WARNING, errno,
P_MSG_XATTR_FAILED, "Posix acl is not set "
"properly at the backend");
- ret = -1;
goto out;
}
@@ -3384,20 +3381,25 @@ posix_setxattr (call_frame_t *frame, xlator_t *this,
gf_msg (this->name, GF_LOG_WARNING, ENOMEM,
P_MSG_BUFFER_OVERFLOW, "size of acl is more"
"than the buffer");
- ret = -1;
goto out;
}
acl_xattr = GF_REALLOC (acl_xattr, acl_size);
+ if (!acl_xattr)
+ goto out;
+
ret = dict_set_bin (xattr, POSIX_ACL_DEFAULT_XATTR,
acl_xattr, acl_size);
- if (ret) {
+ if (ret)
gf_msg (this->name, GF_LOG_WARNING, 0,
P_MSG_SET_XDATA_FAIL, "failed to set"
"xdata for acl");
- ret = -1;
- goto out;
- }
+
+ /*
+ * dict_unref() will call GF_FREE() indirectly, so to avoid
+ * double freeing acl_xattr in out, just set it as NULL here
+ */
+ acl_xattr = NULL;
}
out:
SET_TO_OLD_FS_ID ();
@@ -3406,9 +3408,7 @@ out:
if (xattr)
dict_unref(xattr);
-
- if (acl_xattr)
- GF_FREE (acl_xattr);
+ GF_FREE (acl_xattr);
return 0;
}
--
1.7.1