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authorRijo Thomas <Rijo-john.Thomas@amd.com>2023-02-28 15:11:20 +0530
committerJens Wiklander <jens.wiklander@linaro.org>2023-02-28 18:39:19 +0100
commitf8502fba45bd30e1a6a354d9d898bc99d1a11e6d (patch)
tree590c40c2643308ba20233918ef7068e7eb02ee42 /drivers/tee/amdtee
parentc9c3395d5e3dcc6daee66c6908354d47bf98cb0c (diff)
tee: amdtee: fix race condition in amdtee_open_session
There is a potential race condition in amdtee_open_session that may lead to use-after-free. For instance, in amdtee_open_session() after sess->sess_mask is set, and before setting: sess->session_info[i] = session_info; if amdtee_close_session() closes this same session, then 'sess' data structure will be released, causing kernel panic when 'sess' is accessed within amdtee_open_session(). The solution is to set the bit sess->sess_mask as the last step in amdtee_open_session(). Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver") Cc: stable@vger.kernel.org Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com> Acked-by: Sumit Garg <sumit.garg@linaro.org> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Diffstat (limited to 'drivers/tee/amdtee')
-rw-r--r--drivers/tee/amdtee/core.c29
1 files changed, 14 insertions, 15 deletions
diff --git a/drivers/tee/amdtee/core.c b/drivers/tee/amdtee/core.c
index 297dc62bca29..372d64756ed6 100644
--- a/drivers/tee/amdtee/core.c
+++ b/drivers/tee/amdtee/core.c
@@ -267,35 +267,34 @@ int amdtee_open_session(struct tee_context *ctx,
goto out;
}
+ /* Open session with loaded TA */
+ handle_open_session(arg, &session_info, param);
+ if (arg->ret != TEEC_SUCCESS) {
+ pr_err("open_session failed %d\n", arg->ret);
+ handle_unload_ta(ta_handle);
+ kref_put(&sess->refcount, destroy_session);
+ goto out;
+ }
+
/* Find an empty session index for the given TA */
spin_lock(&sess->lock);
i = find_first_zero_bit(sess->sess_mask, TEE_NUM_SESSIONS);
- if (i < TEE_NUM_SESSIONS)
+ if (i < TEE_NUM_SESSIONS) {
+ sess->session_info[i] = session_info;
+ set_session_id(ta_handle, i, &arg->session);
set_bit(i, sess->sess_mask);
+ }
spin_unlock(&sess->lock);
if (i >= TEE_NUM_SESSIONS) {
pr_err("reached maximum session count %d\n", TEE_NUM_SESSIONS);
+ handle_close_session(ta_handle, session_info);
handle_unload_ta(ta_handle);
kref_put(&sess->refcount, destroy_session);
rc = -ENOMEM;
goto out;
}
- /* Open session with loaded TA */
- handle_open_session(arg, &session_info, param);
- if (arg->ret != TEEC_SUCCESS) {
- pr_err("open_session failed %d\n", arg->ret);
- spin_lock(&sess->lock);
- clear_bit(i, sess->sess_mask);
- spin_unlock(&sess->lock);
- handle_unload_ta(ta_handle);
- kref_put(&sess->refcount, destroy_session);
- goto out;
- }
-
- sess->session_info[i] = session_info;
- set_session_id(ta_handle, i, &arg->session);
out:
free_pages((u64)ta, get_order(ta_size));
return rc;