* [PATCH 1/2] android: binder: More offset validation
2016-02-10 5:05 [PATCH 0/2] Binder updates from the experiemental/android-4.4 tree John Stultz
@ 2016-02-10 5:05 ` John Stultz
2016-02-10 5:05 ` [PATCH 2/2] android: drivers: Avoid debugfs race in binder John Stultz
1 sibling, 0 replies; 3+ messages in thread
From: John Stultz @ 2016-02-10 5:05 UTC (permalink / raw)
To: lkml
Cc: Arve Hjønnevåg, Colin Cross, Dmitry Shmidt,
Rom Lemarchand, Serban Constantinescu, Greg Kroah-Hartman,
Android Kernel Team, John Stultz
From: Arve Hjønnevåg <arve@android.com>
Make sure offsets don't point to overlapping flat_binder_object
structs.
Cc: Colin Cross <ccross@android.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Rom Lemarchand <romlem@google.com>
Cc: Serban Constantinescu <serban.constantinescu@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
drivers/android/binder.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index a39e85f..1db3761 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -1321,6 +1321,7 @@ static void binder_transaction(struct binder_proc *proc,
struct binder_transaction *t;
struct binder_work *tcomplete;
binder_size_t *offp, *off_end;
+ binder_size_t off_min;
struct binder_proc *target_proc;
struct binder_thread *target_thread = NULL;
struct binder_node *target_node = NULL;
@@ -1522,18 +1523,24 @@ static void binder_transaction(struct binder_proc *proc,
goto err_bad_offset;
}
off_end = (void *)offp + tr->offsets_size;
+ off_min = 0;
for (; offp < off_end; offp++) {
struct flat_binder_object *fp;
if (*offp > t->buffer->data_size - sizeof(*fp) ||
+ *offp < off_min ||
t->buffer->data_size < sizeof(*fp) ||
!IS_ALIGNED(*offp, sizeof(u32))) {
- binder_user_error("%d:%d got transaction with invalid offset, %lld\n",
- proc->pid, thread->pid, (u64)*offp);
+ binder_user_error("%d:%d got transaction with invalid offset, %lld (min %lld, max %lld)\n",
+ proc->pid, thread->pid, (u64)*offp,
+ (u64)off_min,
+ (u64)(t->buffer->data_size -
+ sizeof(*fp)));
return_error = BR_FAILED_REPLY;
goto err_bad_offset;
}
fp = (struct flat_binder_object *)(t->buffer->data + *offp);
+ off_min = *offp + sizeof(struct flat_binder_object);
switch (fp->type) {
case BINDER_TYPE_BINDER:
case BINDER_TYPE_WEAK_BINDER: {
--
1.9.1
^ permalink raw reply [flat|nested] 3+ messages in thread* [PATCH 2/2] android: drivers: Avoid debugfs race in binder
2016-02-10 5:05 [PATCH 0/2] Binder updates from the experiemental/android-4.4 tree John Stultz
2016-02-10 5:05 ` [PATCH 1/2] android: binder: More offset validation John Stultz
@ 2016-02-10 5:05 ` John Stultz
1 sibling, 0 replies; 3+ messages in thread
From: John Stultz @ 2016-02-10 5:05 UTC (permalink / raw)
To: lkml
Cc: Riley Andrews, Colin Cross, Arve Hjønnevåg,
Dmitry Shmidt, Rom Lemarchand, Serban Constantinescu,
Greg Kroah-Hartman, Android Kernel Team, John Stultz
From: Riley Andrews <riandrews@android.com>
If a /d/binder/proc/[pid] entry is kept open after linux has
torn down the associated process, binder_proc_show can deference
an invalid binder_proc that has been stashed in the debugfs
inode. Validate that the binder_proc ptr passed into binder_proc_show
has not been freed by looking for it within the global process list
whilst the global lock is held. If the ptr is not valid, print nothing.
Cc: Colin Cross <ccross@android.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Rom Lemarchand <romlem@google.com>
Cc: Serban Constantinescu <serban.constantinescu@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
[jstultz: Minor commit message tweaks]
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
drivers/android/binder.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 1db3761..f0ce995 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3600,13 +3600,24 @@ static int binder_transactions_show(struct seq_file *m, void *unused)
static int binder_proc_show(struct seq_file *m, void *unused)
{
+ struct binder_proc *itr;
struct binder_proc *proc = m->private;
int do_lock = !binder_debug_no_lock;
+ bool valid_proc = false;
if (do_lock)
binder_lock(__func__);
- seq_puts(m, "binder proc state:\n");
- print_binder_proc(m, proc, 1);
+
+ hlist_for_each_entry(itr, &binder_procs, proc_node) {
+ if (itr == proc) {
+ valid_proc = true;
+ break;
+ }
+ }
+ if (valid_proc) {
+ seq_puts(m, "binder proc state:\n");
+ print_binder_proc(m, proc, 1);
+ }
if (do_lock)
binder_unlock(__func__);
return 0;
--
1.9.1
^ permalink raw reply [flat|nested] 3+ messages in thread