From: guoren@kernel.org
To: palmerdabbelt@google.com
Cc: linux-riscv@lists.infradead.org,
Guo Ren <guoren@linux.alibaba.com>,
Andreas Schwab <schwab@linux-m68k.org>,
linux-kernel@vger.kernel.org, Atish Patra <atishp@atishpatra.org>
Subject: [PATCH] riscv: Fixup bootup failure with HARDENED_USERCOPY
Date: Tue, 6 Oct 2020 16:49:33 +0000 [thread overview]
Message-ID: <1602002973-92934-1-git-send-email-guoren@kernel.org> (raw)
From: Guo Ren <guoren@linux.alibaba.com>
As Aurelien has reported:
[ 3.484586] AppArmor: AppArmor sha1 policy hashing enabled
[ 4.749835] Freeing unused kernel memory: 492K
[ 4.752017] Run /init as init process
[ 4.753571] usercopy: Kernel memory overwrite attempt detected to kernel text (offset 507879, size 11)!
[ 4.754838] ------------[ cut here ]------------
[ 4.755651] kernel BUG at mm/usercopy.c:99!
[ 4.756445] Kernel BUG [#1]
[ 4.756815] Modules linked in:
[ 4.757542] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.8.0-1-riscv64 #1 Debian 5.8.7-1
[ 4.758372] epc: ffffffe0003b5120 ra : ffffffe0003b5120 sp : ffffffe07f783ca0
[ 4.758960] gp : ffffffe000cc7230 tp : ffffffe07f77cec0 t0 : ffffffe000cdafc0
[ 4.759772] t1 : 0000000000000064 t2 : 0000000000000000 s0 : ffffffe07f783cf0
[ 4.760534] s1 : ffffffe00095d780 a0 : 000000000000005b a1 : 0000000000000020
[ 4.761309] a2 : 0000000000000005 a3 : 0000000000000000 a4 : ffffffe000c1f340
[ 4.761848] a5 : ffffffe000c1f340 a6 : 0000000000000000 a7 : 0000000000000087
[ 4.762684] s2 : ffffffe000941848 s3 : 000000000007bfe7 s4 : 000000000000000b
[ 4.763500] s5 : 0000000000000000 s6 : ffffffe00091cc00 s7 : fffffffffffff000
[ 4.764376] s8 : 0000003ffffff000 s9 : ffffffe0769f3200 s10: 000000000000000b
[ 4.765208] s11: ffffffe07d548c40 t3 : 0000000000000000 t4 : 000000000001dcd0
[ 4.766059] t5 : ffffffe000cc8510 t6 : ffffffe000cd64aa
[ 4.766712] status: 0000000000000120 badaddr: 0000000000000000 cause: 0000000000000003
[ 4.768308] ---[ end trace 1f8e733e834d4c3e ]---
[ 4.769129] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
[ 4.770070] SMP: stopping secondary CPUs
[ 4.771110] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---
Above failure is relate to commit: a0fa4027dc911 (riscv: Fixup
static_obj() fail). When we expand static_obj include INIT_DATA,
we also include INIT_TEXT into usercopy check kernel text:
/* Is this address range in the kernel text area? */
static inline void check_kernel_text_object(const unsigned long ptr,
unsigned long n, bool to_user)
{
unsigned long textlow = (unsigned long)_stext;
unsigned long texthigh = (unsigned long)_etext;
unsigned long textlow_linear, texthigh_linear;
if (overlaps(ptr, n, textlow, texthigh))
usercopy_abort("kernel text", NULL, to_user, ptr - textlow, n);
When INIT_TEXT/DATA are freed, new allocation will reuse these
memory and overlaps check will be triggered.
The patch met static_obj and check_kernel_text_object requirements.
Link: https://lore.kernel.org/linux-riscv/1593266228-61125-1-git-send-email-guoren@kernel.org/T/#t
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reported-by: Aurelien Jarno <aurelien@aurel32.net>
Tested-by: Aurelien Jarno <aurelien@aurel32.net>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Atish Patra <atishp@atishpatra.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
---
arch/riscv/kernel/vmlinux.lds.S | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S
index f3586e3..34d00d9 100644
--- a/arch/riscv/kernel/vmlinux.lds.S
+++ b/arch/riscv/kernel/vmlinux.lds.S
@@ -22,13 +22,11 @@ SECTIONS
/* Beginning of code and text segment */
. = LOAD_OFFSET;
_start = .;
- _stext = .;
HEAD_TEXT_SECTION
. = ALIGN(PAGE_SIZE);
__init_begin = .;
INIT_TEXT_SECTION(PAGE_SIZE)
- INIT_DATA_SECTION(16)
. = ALIGN(8);
__soc_early_init_table : {
__soc_early_init_table_start = .;
@@ -55,6 +53,7 @@ SECTIONS
. = ALIGN(SECTION_ALIGN);
.text : {
_text = .;
+ _stext = .;
TEXT_TEXT
SCHED_TEXT
CPUIDLE_TEXT
@@ -67,6 +66,8 @@ SECTIONS
_etext = .;
}
+ INIT_DATA_SECTION(16)
+
/* Start of data section */
_sdata = .;
RO_DATA(SECTION_ALIGN)
--
2.7.4
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
next reply other threads:[~2020-10-06 16:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-06 16:49 guoren [this message]
2020-10-07 4:12 ` [PATCH] riscv: Fixup bootup failure with HARDENED_USERCOPY Palmer Dabbelt
2020-10-07 7:12 ` Atish Patra
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=1602002973-92934-1-git-send-email-guoren@kernel.org \
--to=guoren@kernel.org \
--cc=atishp@atishpatra.org \
--cc=guoren@linux.alibaba.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=palmerdabbelt@google.com \
--cc=schwab@linux-m68k.org \
/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).