diff options
| author | Rijo Thomas | 2023-02-28 15:11:20 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-03-30 12:49:29 +0200 |
| commit | a63cce9393e4e7dbc5af82dc87e68cb321cb1a78 (patch) | |
| tree | 3cb13d4398497ed66d85759f866a23da53076e20 /drivers/tee | |
| parent | 8a09fa7be62f5fc499e2713683f7e05a84712b1d (diff) | |
tee: amdtee: fix race condition in amdtee_open_session
commit f8502fba45bd30e1a6a354d9d898bc99d1a11e6d upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tee')
| -rw-r--r-- | drivers/tee/amdtee/core.c | 29 |
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; |