From: Sasha Levin <sashal@kernel.org>
To: Carlos Llamas <cmllamas@google.com>
Cc: stable@vger.kernel.org,
syzbot+7f10c1653e35933c0f1e@syzkaller.appspotmail.com,
Alice Ryhl <aliceryhl@google.com>, Todd Kjos <tkjos@google.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [PATCH 6.1] binder: fix memory leaks of spam and pending work
Date: Sat, 9 Dec 2023 02:09:18 -0500 [thread overview]
Message-ID: <ZXQSnm8Ye5IYzniU@sashalap> (raw)
In-Reply-To: <20231208034923.998315-1-cmllamas@google.com>
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
next prev parent reply other threads:[~2023-12-09 7:09 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-08 3:49 [PATCH 6.1] binder: fix memory leaks of spam and pending work Carlos Llamas
2023-12-09 7:09 ` Sasha Levin [this message]
2023-12-09 11:41 ` Greg Kroah-Hartman
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