[PATCH 6.1] binder: fix memory leaks of spam and pending work

[PATCH 6.1] binder: fix memory leaks of spam and pending work

[Carlos Llamas]

commit 1aa3aaf8953c84bad398adf6c3cabc9d6685bf7d upstream

A transaction complete work is allocated and queued for each
transaction. Under certain conditions the work->type might be marked as
BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT to notify userspace about
potential spamming threads or as BINDER_WORK_TRANSACTION_PENDING when
the target is currently frozen.

However, these work types are not being handled in binder_release_work()
so they will leak during a cleanup. This was reported by syzkaller with
the following kmemleak dump:

BUG: memory leak
unreferenced object 0xffff88810e2d6de0 (size 32):
  comm "syz-executor338", pid 5046, jiffies 4294968230 (age 13.590s)
  hex dump (first 32 bytes):
    e0 6d 2d 0e 81 88 ff ff e0 6d 2d 0e 81 88 ff ff  .m-......m-.....
    04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff81573b75>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1114
    [<ffffffff83d41873>] kmalloc include/linux/slab.h:599 [inline]
    [<ffffffff83d41873>] kzalloc include/linux/slab.h:720 [inline]
    [<ffffffff83d41873>] binder_transaction+0x573/0x4050 drivers/android/binder.c:3152
    [<ffffffff83d45a05>] binder_thread_write+0x6b5/0x1860 drivers/android/binder.c:4010
    [<ffffffff83d486dc>] binder_ioctl_write_read drivers/android/binder.c:5066 [inline]
    [<ffffffff83d486dc>] binder_ioctl+0x1b2c/0x3cf0 drivers/android/binder.c:5352
    [<ffffffff816b25f2>] vfs_ioctl fs/ioctl.c:51 [inline]
    [<ffffffff816b25f2>] __do_sys_ioctl fs/ioctl.c:871 [inline]
    [<ffffffff816b25f2>] __se_sys_ioctl fs/ioctl.c:857 [inline]
    [<ffffffff816b25f2>] __x64_sys_ioctl+0xf2/0x140 fs/ioctl.c:857
    [<ffffffff84b30008>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff84b30008>] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
    [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fix the leaks by kfreeing these work types in binder_release_work() and
handle them as a BINDER_WORK_TRANSACTION_COMPLETE cleanup.

Cc: stable@vger.kernel.org
Fixes: a7dc1e6f99df ("binder: tell userspace to dump current backtrace when detected oneway spamming")
Reported-by: syzbot+7f10c1653e35933c0f1e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7f10c1653e35933c0f1e
Suggested-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Todd Kjos <tkjos@google.com>
Link: https://lore.kernel.org/r/20230922175138.230331-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[cmllamas: backport to v6.1 by dropping BINDER_WORK_TRANSACTION_PENDING
 as commit 0567461a7a6e is not present. Remove fixes tag accordingly.]
Signed-off-by: Carlos Llamas <cmllamas@google.com>
---
 drivers/android/binder.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index e4a6da81cd4b..9cc3a2b1b4fc 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -4788,6 +4788,7 @@ static void binder_release_work(struct binder_proc *proc,
 				"undelivered TRANSACTION_ERROR: %u\n",
 				e->cmd);
 		} break;
+		case BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT:
 		case BINDER_WORK_TRANSACTION_COMPLETE: {
 			binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
 				"undelivered TRANSACTION_COMPLETE\n");

base-commit: c6114c845984144944f1abc07c61de219367a4da
-- 
2.43.0.472.g3155946c3a-goog

Re: [PATCH 6.1] binder: fix memory leaks of spam and pending work

[Sasha Levin]

On Fri, Dec 08, 2023 at 03:49:23AM +0000, Carlos Llamas wrote:
>commit 1aa3aaf8953c84bad398adf6c3cabc9d6685bf7d upstream
>
>A transaction complete work is allocated and queued for each
>transaction. Under certain conditions the work->type might be marked as
>BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT to notify userspace about
>potential spamming threads or as BINDER_WORK_TRANSACTION_PENDING when
>the target is currently frozen.
>
>However, these work types are not being handled in binder_release_work()
>so they will leak during a cleanup. This was reported by syzkaller with
>the following kmemleak dump:
>
>BUG: memory leak
>unreferenced object 0xffff88810e2d6de0 (size 32):
>  comm "syz-executor338", pid 5046, jiffies 4294968230 (age 13.590s)
>  hex dump (first 32 bytes):
>    e0 6d 2d 0e 81 88 ff ff e0 6d 2d 0e 81 88 ff ff  .m-......m-.....
>    04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>  backtrace:
>    [<ffffffff81573b75>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1114
>    [<ffffffff83d41873>] kmalloc include/linux/slab.h:599 [inline]
>    [<ffffffff83d41873>] kzalloc include/linux/slab.h:720 [inline]
>    [<ffffffff83d41873>] binder_transaction+0x573/0x4050 drivers/android/binder.c:3152
>    [<ffffffff83d45a05>] binder_thread_write+0x6b5/0x1860 drivers/android/binder.c:4010
>    [<ffffffff83d486dc>] binder_ioctl_write_read drivers/android/binder.c:5066 [inline]
>    [<ffffffff83d486dc>] binder_ioctl+0x1b2c/0x3cf0 drivers/android/binder.c:5352
>    [<ffffffff816b25f2>] vfs_ioctl fs/ioctl.c:51 [inline]
>    [<ffffffff816b25f2>] __do_sys_ioctl fs/ioctl.c:871 [inline]
>    [<ffffffff816b25f2>] __se_sys_ioctl fs/ioctl.c:857 [inline]
>    [<ffffffff816b25f2>] __x64_sys_ioctl+0xf2/0x140 fs/ioctl.c:857
>    [<ffffffff84b30008>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>    [<ffffffff84b30008>] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
>    [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
>Fix the leaks by kfreeing these work types in binder_release_work() and
>handle them as a BINDER_WORK_TRANSACTION_COMPLETE cleanup.
>
>Cc: stable@vger.kernel.org
>Fixes: a7dc1e6f99df ("binder: tell userspace to dump current backtrace when detected oneway spamming")
>Reported-by: syzbot+7f10c1653e35933c0f1e@syzkaller.appspotmail.com
>Closes: https://syzkaller.appspot.com/bug?extid=7f10c1653e35933c0f1e
>Suggested-by: Alice Ryhl <aliceryhl@google.com>
>Signed-off-by: Carlos Llamas <cmllamas@google.com>
>Reviewed-by: Alice Ryhl <aliceryhl@google.com>
>Acked-by: Todd Kjos <tkjos@google.com>
>Link: https://lore.kernel.org/r/20230922175138.230331-1-cmllamas@google.com
>Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>[cmllamas: backport to v6.1 by dropping BINDER_WORK_TRANSACTION_PENDING
> as commit 0567461a7a6e is not present. Remove fixes tag accordingly.]

Queued up, thanks!

-- 
Thanks,
Sasha

Re: [PATCH 6.1] binder: fix memory leaks of spam and pending work

[Greg Kroah-Hartman]

On Sat, Dec 09, 2023 at 02:09:18AM -0500, Sasha Levin wrote:
> On Fri, Dec 08, 2023 at 03:49:23AM +0000, Carlos Llamas wrote:
> > commit 1aa3aaf8953c84bad398adf6c3cabc9d6685bf7d upstream
> > 
> > A transaction complete work is allocated and queued for each
> > transaction. Under certain conditions the work->type might be marked as
> > BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT to notify userspace about
> > potential spamming threads or as BINDER_WORK_TRANSACTION_PENDING when
> > the target is currently frozen.
> > 
> > However, these work types are not being handled in binder_release_work()
> > so they will leak during a cleanup. This was reported by syzkaller with
> > the following kmemleak dump:
> > 
> > BUG: memory leak
> > unreferenced object 0xffff88810e2d6de0 (size 32):
> >  comm "syz-executor338", pid 5046, jiffies 4294968230 (age 13.590s)
> >  hex dump (first 32 bytes):
> >    e0 6d 2d 0e 81 88 ff ff e0 6d 2d 0e 81 88 ff ff  .m-......m-.....
> >    04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
> >  backtrace:
> >    [<ffffffff81573b75>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1114
> >    [<ffffffff83d41873>] kmalloc include/linux/slab.h:599 [inline]
> >    [<ffffffff83d41873>] kzalloc include/linux/slab.h:720 [inline]
> >    [<ffffffff83d41873>] binder_transaction+0x573/0x4050 drivers/android/binder.c:3152
> >    [<ffffffff83d45a05>] binder_thread_write+0x6b5/0x1860 drivers/android/binder.c:4010
> >    [<ffffffff83d486dc>] binder_ioctl_write_read drivers/android/binder.c:5066 [inline]
> >    [<ffffffff83d486dc>] binder_ioctl+0x1b2c/0x3cf0 drivers/android/binder.c:5352
> >    [<ffffffff816b25f2>] vfs_ioctl fs/ioctl.c:51 [inline]
> >    [<ffffffff816b25f2>] __do_sys_ioctl fs/ioctl.c:871 [inline]
> >    [<ffffffff816b25f2>] __se_sys_ioctl fs/ioctl.c:857 [inline]
> >    [<ffffffff816b25f2>] __x64_sys_ioctl+0xf2/0x140 fs/ioctl.c:857
> >    [<ffffffff84b30008>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> >    [<ffffffff84b30008>] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
> >    [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
> > 
> > Fix the leaks by kfreeing these work types in binder_release_work() and
> > handle them as a BINDER_WORK_TRANSACTION_COMPLETE cleanup.
> > 
> > Cc: stable@vger.kernel.org
> > Fixes: a7dc1e6f99df ("binder: tell userspace to dump current backtrace when detected oneway spamming")
> > Reported-by: syzbot+7f10c1653e35933c0f1e@syzkaller.appspotmail.com
> > Closes: https://syzkaller.appspot.com/bug?extid=7f10c1653e35933c0f1e
> > Suggested-by: Alice Ryhl <aliceryhl@google.com>
> > Signed-off-by: Carlos Llamas <cmllamas@google.com>
> > Reviewed-by: Alice Ryhl <aliceryhl@google.com>
> > Acked-by: Todd Kjos <tkjos@google.com>
> > Link: https://lore.kernel.org/r/20230922175138.230331-1-cmllamas@google.com
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > [cmllamas: backport to v6.1 by dropping BINDER_WORK_TRANSACTION_PENDING
> > as commit 0567461a7a6e is not present. Remove fixes tag accordingly.]
> 
> Queued up, thanks!

Did you not push this out?  I don't see this in the queue at the moment.

thanks,

greg k-h