From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 84FF221D58F; Sat, 7 Jun 2025 10:11:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749291114; cv=none; b=GQs096QIR/cZnPixHnnZoqWGMnncIx+OeMxF3LZ8IKmqjHyuMUjtfN9fexyPMBshHpt18jvGSH5qhiMbQmpYgi8tldC8NF6htEk9cE8sKfwnFZCR8HsVoNhW2F6G8ngli44s9/WLJWRa6wNqSxSPEz6IY6900589cOL8HHLeKMo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749291114; c=relaxed/simple; bh=C+otZMIHTCRpH2lzMJX954T7xRVU3nNb7Jgy90CYyTU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Dd7+fnPqe3cp8yO8/HMUayPrVAxKymG74T6Yu9v1x0EW7NYCfpty1ki8cMQdEHrKiMlbuhFfMPo0Z15fsoULq+tt+iSmcnlzs8siZ0I55SRQqiNbqEtJgSUFq9ziCVze1BdbEWmoKEm2Ofvy65Bt6+NJ/3E3eVpBcEl3mcsNnOE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=A8r1XOuT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="A8r1XOuT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B916FC4CEF1; Sat, 7 Jun 2025 10:11:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1749291114; bh=C+otZMIHTCRpH2lzMJX954T7xRVU3nNb7Jgy90CYyTU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A8r1XOuT3JLZCkqw6Z634aUp8HgKYVuGrNBAZOkt2Y1V/nCL+6UbrI05BeZ/jXQxF 50+xTYuIMPnItSk14sxahFteIkxbdcj4JbRvhF1AP2t4ys473M3f642D+UV0MplgLo KROyAmu8AH6fKcXd640KbgDrIYwAkmnfxnTgiGjU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+4af454407ec393de51d6@syzkaller.appspotmail.com, Carlos Llamas Subject: [PATCH 6.15 28/34] binder: fix yet another UAF in binder_devices Date: Sat, 7 Jun 2025 12:08:09 +0200 Message-ID: <20250607100720.816894979@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250607100719.711372213@linuxfoundation.org> References: <20250607100719.711372213@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Carlos Llamas commit 9857af0fcff385c75433f2162c30c62eb912ef6d upstream. Commit e77aff5528a18 ("binderfs: fix use-after-free in binder_devices") addressed a use-after-free where devices could be released without first being removed from the binder_devices list. However, there is a similar path in binder_free_proc() that was missed: ================================================================== BUG: KASAN: slab-use-after-free in binder_remove_device+0xd4/0x100 Write of size 8 at addr ffff0000c773b900 by task umount/467 CPU: 12 UID: 0 PID: 467 Comm: umount Not tainted 6.15.0-rc7-00138-g57483a362741 #9 PREEMPT Hardware name: linux,dummy-virt (DT) Call trace: binder_remove_device+0xd4/0x100 binderfs_evict_inode+0x230/0x2f0 evict+0x25c/0x5dc iput+0x304/0x480 dentry_unlink_inode+0x208/0x46c __dentry_kill+0x154/0x530 [...] Allocated by task 463: __kmalloc_cache_noprof+0x13c/0x324 binderfs_binder_device_create.isra.0+0x138/0xa60 binder_ctl_ioctl+0x1ac/0x230 [...] Freed by task 215: kfree+0x184/0x31c binder_proc_dec_tmpref+0x33c/0x4ac binder_deferred_func+0xc10/0x1108 process_one_work+0x520/0xba4 [...] ================================================================== Call binder_remove_device() within binder_free_proc() to ensure the device is removed from the binder_devices list before being kfreed. Cc: stable@vger.kernel.org Fixes: 12d909cac1e1 ("binderfs: add new binder devices to binder_devices") Reported-by: syzbot+4af454407ec393de51d6@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=4af454407ec393de51d6 Tested-by: syzbot+4af454407ec393de51d6@syzkaller.appspotmail.com Signed-off-by: Carlos Llamas Link: https://lore.kernel.org/r/20250524220758.915028-1-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -5246,6 +5246,7 @@ static void binder_free_proc(struct bind __func__, proc->outstanding_txns); device = container_of(proc->context, struct binder_device, context); if (refcount_dec_and_test(&device->ref)) { + binder_remove_device(device); kfree(proc->context->name); kfree(device); }