From: Xie Yuanbin <xieyuanbin1@huawei.com>
To: <linux@armlinux.org.uk>
Cc: <akpm@linux-foundation.org>, <david@kernel.org>,
<liam@infradead.org>, <liaohua4@huawei.com>,
<lilinjie8@huawei.com>, <linusw@kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
<ljs@kernel.org>, <mhocko@suse.com>, <rppt@kernel.org>,
<sunnanyong@huawei.com>, <surenb@google.com>, <vbabka@kernel.org>,
<xieyuanbin1@huawei.com>, <xiqi2@huawei.com>
Subject: Re: [PATCH v3 1/2] ARM: mm: fix use-after-free in __do_user_fault() under CONFIG_DEBUG_USER
Date: Tue, 7 Jul 2026 21:14:09 +0800 [thread overview]
Message-ID: <20260707131409.79043-1-xieyuanbin1@huawei.com> (raw)
In-Reply-To: <akzpuerKqOY7qfFi@shell.armlinux.org.uk>
On Tue, 7 Jul 2026 12:57:45 +0100, Russell King wrote:
> No. This information is useful debug for kernel oops.
For kernel oops, I think it should be `!user_mode(regs)`, Qi Xi's reply:
On Tue, 7 Jul 2026 19:48:12 +0800, Qi Xi wrote:
> For do_DataAbort() fallback:
>
> if (user_mode(regs)) {
> if (addr < TASK_SIZE) {
> mmap_read_lock(current->mm);
> show_pte(KERN_ALERT, current->mm, addr);
> mmap_read_unlock(current->mm);
> }
> } else {
> show_pte(KERN_ALERT, current->mm, addr);
> }
changes nothing to kernel oops. It only skip show_pte() for user-mode
faults, and the fault addr is a kernel address, which means a user
program is trying to access a kernel address.
I think it is reasonable to skip show_pte() in this case?
next prev parent reply other threads:[~2026-07-07 13:15 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-26 7:30 [PATCH v3 0/2] ARM: mm: fix use-after-free in show_pte() Qi Xi
2026-06-26 7:30 ` [PATCH v3 1/2] ARM: mm: fix use-after-free in __do_user_fault() under CONFIG_DEBUG_USER Qi Xi
2026-06-26 9:44 ` Russell King
2026-06-27 1:39 ` Qi Xi
2026-07-06 13:32 ` Xie Yuanbin
2026-07-07 11:48 ` Qi Xi
2026-07-07 11:57 ` Russell King
2026-07-07 12:47 ` Qi Xi
2026-07-07 12:47 ` Lorenzo Stoakes
2026-07-07 13:14 ` Xie Yuanbin [this message]
2026-07-07 13:20 ` Lorenzo Stoakes
2026-07-07 14:04 ` Xie Yuanbin
2026-07-07 15:34 ` Russell King
2026-07-10 2:32 ` Qi Xi
2026-07-11 7:27 ` Lorenzo Stoakes
2026-07-11 7:56 ` Xie Yuanbin
2026-07-11 8:05 ` Lorenzo Stoakes
2026-07-11 8:13 ` Xie Yuanbin
2026-07-07 12:46 ` Lorenzo Stoakes
2026-07-07 13:35 ` Xie Yuanbin
2026-07-11 6:43 ` Lorenzo Stoakes
2026-06-26 7:30 ` [PATCH v3 2/2] ARM: mm: protect show_pte() in do_DataAbort() fallback path Qi Xi
2026-06-26 9:45 ` Russell King
2026-06-26 10:16 ` Xie Yuanbin
2026-06-26 12:37 ` Russell King
2026-06-27 1:22 ` Xie Yuanbin
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