]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
capabilities: fix potential memleak on error path from vfs_getxattr_alloc()
authorGaosheng Cui <cuigaosheng1@huawei.com>
Tue, 25 Oct 2022 13:33:57 +0000 (21:33 +0800)
committerPaul Moore <paul@paul-moore.com>
Fri, 28 Oct 2022 10:44:33 +0000 (06:44 -0400)
commit8cf0a1bc12870d148ae830a4ba88cfdf0e879cee
treec5937416b5bb6b933ef771b53105d3806ba02969
parent9abf2313adc1ca1b6180c508c25f22f9395cc780
capabilities: fix potential memleak on error path from vfs_getxattr_alloc()

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@vger.kernel.org
Fixes: 8db6c34f1dbc ("Introduce v3 namespaced file capabilities")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
[PM: subject line and backtrace tweaks]
Signed-off-by: Paul Moore <paul@paul-moore.com>
security/commoncap.c