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 Change-Id: Ia7b59804a0bdbd51191bbcca556414840307c623 --- 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 cebb2cd1876c..c2c411c458b2 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -3107,7 +3107,7 @@ 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 0d4cb64cae1f..3f6b8195ae9e 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -985,6 +985,11 @@ 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;