[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240815070900.GB12106@google.com>
Date: Thu, 15 Aug 2024 16:09:00 +0900
From: Sergey Senozhatsky <senozhatsky@...omium.org>
To: Matthew Brost <matthew.brost@...el.com>
Cc: Tejun Heo <tj@...nel.org>, Lai Jiangshan <jiangshanlai@...il.com>,
linux-kernel@...r.kernel.org,
Sergey Senozhatsky <senozhatsky@...omium.org>
Subject: Re: [PATCH] workqueue: fix null-ptr-deref on __alloc_workqueue()
error
On (24/08/15 16:02), Sergey Senozhatsky wrote:
> wq->lockdep_map is set only after __alloc_workqueue()
> successfully returns. However, on its error path
> __alloc_workqueue() may call destroy_workqueue() which
> expects wq->lockdep_map to be already set, which results
> in a null-ptr-deref in touch_wq_lockdep_map().
>
> Add a simple NULL-check to touch_wq_lockdep_map().
>
> Oops: general protection fault, probably for non-canonical address
> KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
> RIP: 0010:__lock_acquire+0x81/0x7800
> [..]
> Call Trace:
> <TASK>
> ? __die_body+0x66/0xb0
> ? die_addr+0xb2/0xe0
> ? exc_general_protection+0x300/0x470
> ? asm_exc_general_protection+0x22/0x30
> ? __lock_acquire+0x81/0x7800
> ? mark_lock+0x94/0x330
> ? __lock_acquire+0x12fd/0x7800
> ? __lock_acquire+0x3439/0x7800
> lock_acquire+0x14c/0x3e0
> ? __flush_workqueue+0x167/0x13a0
> ? __init_swait_queue_head+0xaf/0x150
> ? __flush_workqueue+0x167/0x13a0
> __flush_workqueue+0x17d/0x13a0
> ? __flush_workqueue+0x167/0x13a0
> ? lock_release+0x50f/0x830
> ? drain_workqueue+0x94/0x300
> drain_workqueue+0xe3/0x300
> destroy_workqueue+0xac/0xc40
> ? workqueue_sysfs_register+0x159/0x2f0
> __alloc_workqueue+0x1506/0x1760
> alloc_workqueue+0x61/0x150
> ...
>
> Signed-off-by: Sergey Senozhatsky <senozhatsky@...omium.org>
> ---
> kernel/workqueue.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index bfeeefeee332..59bd2c1e55af 100644
> --- a/kernel/workqueue.c
> +++ b/kernel/workqueue.c
> @@ -3870,6 +3870,9 @@ static bool flush_workqueue_prep_pwqs(struct workqueue_struct *wq,
> static void touch_wq_lockdep_map(struct workqueue_struct *wq)
> {
> #ifdef CONFIG_LOCKDEP
> + if (unlikely(!wq->lockdep_map))
> + return;
> +
> if (wq->flags & WQ_BH)
> local_bh_disable();
Oh, okay, so this is related to [1]
workqueue: Split alloc_workqueue into internal function and lockdep init
Cc-ing Matthew on this.
[1] https://lore.kernel.org/all/20240809222827.3211998-2-matthew.brost@intel.com/
Powered by blists - more mailing lists