From: Gaosheng Cui <cuigaosheng1@xxxxxxxxxx>
commit 8cf0a1bc12870d148ae830a4ba88cfdf0e879cee upstream.
In cap_inode_getsecurity(), we will use vfs_getxattr_alloc() to
complete the memory allocation of tmpbuf, if we have completed
the memory allocation of tmpbuf, but failed to call handler->get(...),
there will be a memleak in below logic:
|-- ret = (int)vfs_getxattr_alloc(mnt_userns, ...)
| /* ^^^ alloc for tmpbuf */
|-- value = krealloc(*xattr_value, error + 1, flags)
| /* ^^^ alloc memory */
|-- error = handler->get(handler, ...)
| /* error! */
|-- *xattr_value = value
| /* xattr_value is &tmpbuf (memory leak!) */
So we will try to free(tmpbuf) after vfs_getxattr_alloc() fails to fix it.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 8db6c34f1dbc ("Introduce v3 namespaced file capabilities")
Signed-off-by: Gaosheng Cui <cuigaosheng1@xxxxxxxxxx>
Acked-by: Serge Hallyn <serge@xxxxxxxxxx>
[PM: subject line and backtrace tweaks]
Signed-off-by: Paul Moore <paul@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
security/commoncap.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -391,8 +391,10 @@ int cap_inode_getsecurity(struct inode *
&tmpbuf, size, GFP_NOFS);
dput(dentry);
- if (ret < 0 || !tmpbuf)
- return ret;
+ if (ret < 0 || !tmpbuf) {
+ size = ret;
+ goto out_free;
+ }
fs_ns = inode->i_sb->s_user_ns;
cap = (struct vfs_cap_data *) tmpbuf;
