From 212265e5ad726ed7fd2ec7d61d36d9e0b0d3e655 Mon Sep 17 00:00:00 2001 From: Arve Hjønnevåg Date: Tue, 9 Feb 2016 21:05:32 -0800 Subject: android: binder: More offset validation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Make sure offsets don't point to overlapping flat_binder_object structs. Cc: Colin Cross Cc: Arve Hjønnevåg Cc: Dmitry Shmidt Cc: Rom Lemarchand Cc: Serban Constantinescu Cc: Greg Kroah-Hartman Cc: Android Kernel Team Signed-off-by: Dmitry Shmidt Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'drivers/android/binder.c') diff --git a/drivers/android/binder.c b/drivers/android/binder.c index a39e85f9efa9..1db376184955 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: { -- cgit v1.2.3 From 83050a4e21979fe1821916fce2fca36255569ed3 Mon Sep 17 00:00:00 2001 From: Riley Andrews Date: Tue, 9 Feb 2016 21:05:33 -0800 Subject: android: drivers: Avoid debugfs race in binder MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Cc: Arve Hjønnevåg Cc: Dmitry Shmidt Cc: Rom Lemarchand Cc: Serban Constantinescu Cc: Greg Kroah-Hartman Cc: Android Kernel Team Signed-off-by: Dmitry Shmidt [jstultz: Minor commit message tweaks] Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) (limited to 'drivers/android/binder.c') diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 1db376184955..f0ce9959d14d 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; -- cgit v1.2.3