From: Kefeng Wang <wangkefeng.wang@huawei.com>
To: Russell King <linux@armlinux.org.uk>,
<linux-arm-kernel@lists.infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
<linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Jungseung Lee <js07.lee@gmail.com>,
Kefeng Wang <wangkefeng.wang@huawei.com>
Subject: [PATCH v2 7/7] ARM: mm: Fix PXN process with LPAE feature
Date: Wed, 2 Jun 2021 15:02:46 +0800 [thread overview]
Message-ID: <20210602070246.83990-8-wangkefeng.wang@huawei.com> (raw)
In-Reply-To: <20210602070246.83990-1-wangkefeng.wang@huawei.com>
When user code execution with privilege mode, it will lead to
infinite loop in the page fault handler if ARM_LPAE enabled,
The issue could be reproduced with
"echo EXEC_USERSPACE > /sys/kernel/debug/provoke-crash/DIRECT"
Lets' fix it by adding the check in do_page_fault() and panic
when ARM_LPAE enabled.
Fixes: 1d4d37159d01 ("ARM: 8235/1: Support for the PXN CPU feature on ARMv7")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
arch/arm/mm/fault.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 7cfa9a59d3ec..279bbeb33b48 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -257,8 +257,14 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
vm_flags = VM_WRITE;
}
- if (fsr & FSR_LNX_PF)
+ if (fsr & FSR_LNX_PF) {
vm_flags = VM_EXEC;
+#ifdef CONFIG_ARM_LPAE
+ if (addr && addr < TASK_SIZE && !user_mode(regs))
+ die_kernel_fault("execution of user memory",
+ addr, fsr, regs);
+#endif
+ }
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
--
2.26.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-06-02 6:56 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-02 7:02 [PATCH v2 0/7] ARM: mm: cleanup page fault and fix pxn process issue Kefeng Wang
2021-06-02 7:02 ` [PATCH v2 1/7] ARM: mm: Rafactor the __do_page_fault() Kefeng Wang
2021-06-02 10:29 ` Russell King (Oracle)
2021-06-02 7:02 ` [PATCH v2 2/7] ARM: mm: Kill task_struct argument for __do_page_fault() Kefeng Wang
2021-06-02 10:31 ` Russell King (Oracle)
2021-06-02 7:02 ` [PATCH v2 3/7] ARM: mm: Cleanup access_error() Kefeng Wang
2021-06-02 10:39 ` Russell King (Oracle)
2021-06-02 7:02 ` [PATCH v2 4/7] ARM: mm: print out correct page table entries Kefeng Wang
2021-06-02 10:44 ` Russell King (Oracle)
2021-06-02 11:24 ` Kefeng Wang
2021-06-02 7:02 ` [PATCH v2 5/7] ARM: mm: Print physical address of page table base in show_pte() Kefeng Wang
2021-06-02 10:47 ` Russell King (Oracle)
2021-06-02 11:25 ` Kefeng Wang
2021-06-02 7:02 ` [PATCH v2 6/7] ARM: mm: Provide die_kernel_fault() helper Kefeng Wang
2021-06-02 10:49 ` Russell King (Oracle)
2021-06-02 7:02 ` Kefeng Wang [this message]
2021-06-02 10:52 ` [PATCH v2 7/7] ARM: mm: Fix PXN process with LPAE feature Russell King (Oracle)
2021-06-02 15:13 ` Kefeng Wang
2021-06-02 15:58 ` Russell King (Oracle)
2021-06-03 9:38 ` Kefeng Wang
2021-06-07 8:32 ` Kefeng Wang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210602070246.83990-8-wangkefeng.wang@huawei.com \
--to=wangkefeng.wang@huawei.com \
--cc=akpm@linux-foundation.org \
--cc=catalin.marinas@arm.com \
--cc=js07.lee@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@armlinux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).