From 1c1f571840bc39f66f598b615524ef79c62a53ac Mon Sep 17 00:00:00 2001 From: Todd Kjos Date: Wed, 10 Nov 2021 15:00:25 -0800 Subject: [PATCH] BACKPORT: binder: use cred instead of task for getsecid 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 Suggested-by: Stephen Smalley Reported-by: kernel test robot Acked-by: Casey Schaufler Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman Bug: 200688826 [ fixed minor conflict ] Signed-off-by: Todd Kjos Change-Id: I4ef69da21d7ae651895c498b3aa224f180026fa9 --- 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 03388c75a0e6..2ae6591d0dd3 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2841,7 +2841,7 @@ static void binder_transaction(struct binder_proc *proc, u32 secid; size_t added_size; - security_task_getsecid(proc->tsk, &secid); + security_cred_getsecid(binder_get_cred(proc), &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 6465e86b5013..a52748661a38 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;