There is a potential race condition in amdtee_close_session that may
cause use-after-free in amdtee_open_session. For instance, if a session
has refcount == 1, and one thread tries to free this session via:
kref_put(&sess->refcount, destroy_session);
the reference count will get decremented, and the next step would be to
call destroy_session(). However, if in another thread,
amdtee_open_session() is called before destroy_session() has completed
execution, alloc_session() may return 'sess' that will be freed up
later in destroy_session() leading to use-after-free in
amdtee_open_session.
To fix this issue, treat decrement of sess->refcount and removal of
'sess' from session list in destroy_session() as a critical section, so
that it is executed atomically.
Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver")
Cc: stable(a)vger.kernel.org
Signed-off-by: Rijo Thomas <Rijo-john.Thomas(a)amd.com>
---
v2:
* Introduced kref_put_mutex() as suggested by Sumit Garg.
drivers/tee/amdtee/core.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/tee/amdtee/core.c b/drivers/tee/amdtee/core.c
index 372d64756ed6..3c15f6a9e91c 100644
--- a/drivers/tee/amdtee/core.c
+++ b/drivers/tee/amdtee/core.c
@@ -217,12 +217,12 @@ static int copy_ta_binary(struct tee_context *ctx, void *ptr, void **ta,
return rc;
}
+/* mutex must be held by caller */
static void destroy_session(struct kref *ref)
{
struct amdtee_session *sess = container_of(ref, struct amdtee_session,
refcount);
- mutex_lock(&session_list_mutex);
list_del(&sess->list_node);
mutex_unlock(&session_list_mutex);
kfree(sess);
@@ -272,7 +272,8 @@ int amdtee_open_session(struct tee_context *ctx,
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);
+ kref_put_mutex(&sess->refcount, destroy_session,
+ &session_list_mutex);
goto out;
}
@@ -290,7 +291,8 @@ int amdtee_open_session(struct tee_context *ctx,
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);
+ kref_put_mutex(&sess->refcount, destroy_session,
+ &session_list_mutex);
rc = -ENOMEM;
goto out;
}
@@ -331,7 +333,7 @@ int amdtee_close_session(struct tee_context *ctx, u32 session)
handle_close_session(ta_handle, session_info);
handle_unload_ta(ta_handle);
- kref_put(&sess->refcount, destroy_session);
+ kref_put_mutex(&sess->refcount, destroy_session, &session_list_mutex);
return 0;
}
--
2.25.1
This suggests a commit (and a follow-up fix for it) from 5.16+ for stable
because it fixes the usage of watchdog.handle_boot_enabled=0 for iTCO,
closing a monitoring gap in OTA update scenarios.
These patches are applicable to and have been tested with 5.15, 5.10 and
5.4 stable heads.
Jan
Cc: Malin Jonsson <malin.jonsson(a)ericsson.com>
Mika Westerberg (2):
watchdog: iTCO_wdt: No need to stop the timer in probe
watchdog: iTCO_wdt: Set NO_REBOOT if the watchdog is not already
running
drivers/watchdog/iTCO_wdt.c | 26 +++++++++++++++++++++-----
1 file changed, 21 insertions(+), 5 deletions(-)
--
2.35.3
Hi,
Please backport commit dad651b2a44e ("nvme-pci: do not set the NUMA node
of device if it has none") to stable branches 6.1, 5.15, 5.10, 5.4,
4.19, and 4.14. The commit fixes a4aea5623d4a ("NVMe: Convert to
blk-mq") which was introduced in v3.19 but I forgot to add this when
sending the patch.
--
Regards,
Pratyush Yadav
Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879