From: Xin Xiong xiongx18@fudan.edu.cn
stable inclusion from stable-v5.10.138 commit 2ceeb3296e9dde1d5772348046affcefdea605e2 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I60QFD
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 11c3627ec6b56c1525013f336f41b79a983b4d46 upstream.
The aa_pivotroot() function has a reference counting bug in a specific path. When aa_replace_current_label() returns on success, the function forgets to decrement the reference count of “target”, which is increased earlier by build_pivotroot(), causing a reference leak.
Fix it by decreasing the refcount of “target” in that path.
Fixes: 2ea3ffb7782a ("apparmor: add mount mediation") Co-developed-by: Xiyu Yang xiyuyang19@fudan.edu.cn Signed-off-by: Xiyu Yang xiyuyang19@fudan.edu.cn Co-developed-by: Xin Tan tanxin.ctf@gmail.com Signed-off-by: Xin Tan tanxin.ctf@gmail.com Signed-off-by: Xin Xiong xiongx18@fudan.edu.cn Signed-off-by: John Johansen john.johansen@canonical.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Wei Li liwei391@huawei.com --- security/apparmor/mount.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/security/apparmor/mount.c b/security/apparmor/mount.c index d51fd3632dce..e64f76d347d6 100644 --- a/security/apparmor/mount.c +++ b/security/apparmor/mount.c @@ -719,6 +719,7 @@ int aa_pivotroot(struct aa_label *label, const struct path *old_path, aa_put_label(target); goto out; } + aa_put_label(target); } else /* already audited error */ error = PTR_ERR(target);