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 A859A5FDD2; Tue, 14 May 2024 11:41:08 +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=1715686868; cv=none; b=i781wKVgjfeoCoffcKdgLkKi9MEJhGbFf5s+/S1wJHw6LsOjGwTh/TcszIxI+ch8jrdFSmF/nvFJvHSM5BEnk4BimssR1dztEpg8HmCnrpfv3+s6EIDha4uqGG7wHogPjrL3wsWzaNCR+bxPjnhvcfi6DFEfR2kT6TToOnu2edI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715686868; c=relaxed/simple; bh=cg8BQAb6jEH/Sxi0rVSz9dhApdHjYCFuGn6acmHddHw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aL9zhviB10ckrO0CbaWaVSQ9EoqsiOW5ODkm+LLeCGlt5gcFIXJ0fhSWlGLFw8M0Taz+CF1QF6LWOzoSgE88R/69orpmZkIzWOkEDhxssZwJZsLreli2AnTerv4Iz+fk3WeD0pBt4ibXRgcFRblxXuvv7tiqfOxez9UI/Fckq8s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=UKmN5JYP; 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="UKmN5JYP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E8E1C32781; Tue, 14 May 2024 11:41:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1715686868; bh=cg8BQAb6jEH/Sxi0rVSz9dhApdHjYCFuGn6acmHddHw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UKmN5JYPJBv1HqaI7gbtbvweeKawvx4Hx2DySTsGuPd90HCTWn8GzIopZ2G/peEmQ 0cWv4ZoTxVmZoMOwlrj/pd5UW1qwLGSQddsfMVI6+Z8R76Il9LocYaYm7p9nZ3fte+ jDSuZldkR5kQh2vESfi8y+xOyyl0CroixH5HwMOI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Duoming Zhou , Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 4.19 48/63] Bluetooth: Fix use-after-free bugs caused by sco_sock_timeout Date: Tue, 14 May 2024 12:20:09 +0200 Message-ID: <20240514100949.827387247@linuxfoundation.org> X-Mailer: git-send-email 2.45.0 In-Reply-To: <20240514100948.010148088@linuxfoundation.org> References: <20240514100948.010148088@linuxfoundation.org> User-Agent: quilt/0.67 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 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Duoming Zhou [ Upstream commit 483bc08181827fc475643272ffb69c533007e546 ] When the sco connection is established and then, the sco socket is releasing, timeout_work will be scheduled to judge whether the sco disconnection is timeout. The sock will be deallocated later, but it is dereferenced again in sco_sock_timeout. As a result, the use-after-free bugs will happen. The root cause is shown below: Cleanup Thread | Worker Thread sco_sock_release | sco_sock_close | __sco_sock_close | sco_sock_set_timer | schedule_delayed_work | sco_sock_kill | (wait a time) sock_put(sk) //FREE | sco_sock_timeout | sock_hold(sk) //USE The KASAN report triggered by POC is shown below: [ 95.890016] ================================================================== [ 95.890496] BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x5e/0x1c0 [ 95.890755] Write of size 4 at addr ffff88800c388080 by task kworker/0:0/7 ... [ 95.890755] Workqueue: events sco_sock_timeout [ 95.890755] Call Trace: [ 95.890755] [ 95.890755] dump_stack_lvl+0x45/0x110 [ 95.890755] print_address_description+0x78/0x390 [ 95.890755] print_report+0x11b/0x250 [ 95.890755] ? __virt_addr_valid+0xbe/0xf0 [ 95.890755] ? sco_sock_timeout+0x5e/0x1c0 [ 95.890755] kasan_report+0x139/0x170 [ 95.890755] ? update_load_avg+0xe5/0x9f0 [ 95.890755] ? sco_sock_timeout+0x5e/0x1c0 [ 95.890755] kasan_check_range+0x2c3/0x2e0 [ 95.890755] sco_sock_timeout+0x5e/0x1c0 [ 95.890755] process_one_work+0x561/0xc50 [ 95.890755] worker_thread+0xab2/0x13c0 [ 95.890755] ? pr_cont_work+0x490/0x490 [ 95.890755] kthread+0x279/0x300 [ 95.890755] ? pr_cont_work+0x490/0x490 [ 95.890755] ? kthread_blkcg+0xa0/0xa0 [ 95.890755] ret_from_fork+0x34/0x60 [ 95.890755] ? kthread_blkcg+0xa0/0xa0 [ 95.890755] ret_from_fork_asm+0x11/0x20 [ 95.890755] [ 95.890755] [ 95.890755] Allocated by task 506: [ 95.890755] kasan_save_track+0x3f/0x70 [ 95.890755] __kasan_kmalloc+0x86/0x90 [ 95.890755] __kmalloc+0x17f/0x360 [ 95.890755] sk_prot_alloc+0xe1/0x1a0 [ 95.890755] sk_alloc+0x31/0x4e0 [ 95.890755] bt_sock_alloc+0x2b/0x2a0 [ 95.890755] sco_sock_create+0xad/0x320 [ 95.890755] bt_sock_create+0x145/0x320 [ 95.890755] __sock_create+0x2e1/0x650 [ 95.890755] __sys_socket+0xd0/0x280 [ 95.890755] __x64_sys_socket+0x75/0x80 [ 95.890755] do_syscall_64+0xc4/0x1b0 [ 95.890755] entry_SYSCALL_64_after_hwframe+0x67/0x6f [ 95.890755] [ 95.890755] Freed by task 506: [ 95.890755] kasan_save_track+0x3f/0x70 [ 95.890755] kasan_save_free_info+0x40/0x50 [ 95.890755] poison_slab_object+0x118/0x180 [ 95.890755] __kasan_slab_free+0x12/0x30 [ 95.890755] kfree+0xb2/0x240 [ 95.890755] __sk_destruct+0x317/0x410 [ 95.890755] sco_sock_release+0x232/0x280 [ 95.890755] sock_close+0xb2/0x210 [ 95.890755] __fput+0x37f/0x770 [ 95.890755] task_work_run+0x1ae/0x210 [ 95.890755] get_signal+0xe17/0xf70 [ 95.890755] arch_do_signal_or_restart+0x3f/0x520 [ 95.890755] syscall_exit_to_user_mode+0x55/0x120 [ 95.890755] do_syscall_64+0xd1/0x1b0 [ 95.890755] entry_SYSCALL_64_after_hwframe+0x67/0x6f [ 95.890755] [ 95.890755] The buggy address belongs to the object at ffff88800c388000 [ 95.890755] which belongs to the cache kmalloc-1k of size 1024 [ 95.890755] The buggy address is located 128 bytes inside of [ 95.890755] freed 1024-byte region [ffff88800c388000, ffff88800c388400) [ 95.890755] [ 95.890755] The buggy address belongs to the physical page: [ 95.890755] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88800c38a800 pfn:0xc388 [ 95.890755] head: order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 [ 95.890755] anon flags: 0x100000000000840(slab|head|node=0|zone=1) [ 95.890755] page_type: 0xffffffff() [ 95.890755] raw: 0100000000000840 ffff888006842dc0 0000000000000000 0000000000000001 [ 95.890755] raw: ffff88800c38a800 000000000010000a 00000001ffffffff 0000000000000000 [ 95.890755] head: 0100000000000840 ffff888006842dc0 0000000000000000 0000000000000001 [ 95.890755] head: ffff88800c38a800 000000000010000a 00000001ffffffff 0000000000000000 [ 95.890755] head: 0100000000000003 ffffea000030e201 ffffea000030e248 00000000ffffffff [ 95.890755] head: 0000000800000000 0000000000000000 00000000ffffffff 0000000000000000 [ 95.890755] page dumped because: kasan: bad access detected [ 95.890755] [ 95.890755] Memory state around the buggy address: [ 95.890755] ffff88800c387f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 95.890755] ffff88800c388000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 95.890755] >ffff88800c388080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 95.890755] ^ [ 95.890755] ffff88800c388100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 95.890755] ffff88800c388180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 95.890755] ================================================================== Fix this problem by adding a check protected by sco_conn_lock to judget whether the conn->hcon is null. Because the conn->hcon will be set to null, when the sock is releasing. Fixes: ba316be1b6a0 ("Bluetooth: schedule SCO timeouts with delayed_work") Signed-off-by: Duoming Zhou Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- net/bluetooth/sco.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c index d8726327bc05e..42b5d56d85a56 100644 --- a/net/bluetooth/sco.c +++ b/net/bluetooth/sco.c @@ -82,6 +82,10 @@ static void sco_sock_timeout(struct work_struct *work) struct sock *sk; sco_conn_lock(conn); + if (!conn->hcon) { + sco_conn_unlock(conn); + return; + } sk = conn->sk; if (sk) sock_hold(sk); -- 2.43.0