From: Todd Kjos <tkjos@google.com> stable inclusion from stable-v5.10.80 commit afbec52fbce006a775edb21f87ccae713bc0e7d6 category: bugfix bugzilla: 188431, https://gitee.com/src-openeuler/kernel/issues/I6DKVG CVE: CVE-2023-20938 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 4d5b5539742d2554591751b4248b0204d20dcc9d upstream. Use the 'struct cred' saved at binder_open() to lookup the security ID via security_cred_getsecid(). This ensures that the security context that opened binder is the one used to generate the secctx. Cc: stable@vger.kernel.org # 5.4+ Fixes: ec74136ded79 ("binder: create node flag to request sender's security context") Signed-off-by: Todd Kjos <tkjos@google.com> Suggested-by: Stephen Smalley <stephen.smalley.work@gmail.com> Reported-by: kernel test robot <lkp@intel.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Li Huafei <lihuafei1@huawei.com> Reviewed-by: Zheng Yejian <zhengyejian1@huawei.com> Reviewed-by: Wang Weiyang <wangweiyang2@huawei.com> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- drivers/android/binder.c | 2 +- include/linux/security.h | 5 +++++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 656593c0e9b1..c07e0da4b42d 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -3138,7 +3138,7 @@ static void binder_transaction(struct binder_proc *proc, u32 secid; size_t added_size; - security_task_getsecid(proc->tsk, &secid); + security_cred_getsecid(proc->cred, &secid); ret = security_secid_to_secctx(secid, &secctx, &secctx_sz); if (ret) { return_error = BR_FAILED_REPLY; diff --git a/include/linux/security.h b/include/linux/security.h index 2960258279cb..016a88f557e8 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -914,6 +914,11 @@ static inline void security_transfer_creds(struct cred *new, { } +static inline void security_cred_getsecid(const struct cred *c, u32 *secid) +{ + *secid = 0; +} + static inline int security_kernel_act_as(struct cred *cred, u32 secid) { return 0; -- 2.25.1