From: Andrew Morton <akpm@linux-foundation.org>
To: adobriyan@gmail.com, akpm@linux-foundation.org,
hkallweit1@gmail.com, keescook@chromium.org, linux-mm@kvack.org,
mcgrof@kernel.org, mhiramat@kernel.org, mhocko@suse.com,
mm-commits@vger.kernel.org, nixiaoming@huawei.com,
rdunlap@infradead.org, stable@vger.kernel.org,
torvalds@linux-foundation.org, vbabka@suse.cz,
yzaikin@google.com
Subject: [patch 18/19] proc_sysctl: fix oops caused by incorrect command parameters
Date: Sat, 23 Jan 2021 21:02:16 -0800 [thread overview]
Message-ID: <20210124050216.W3v89CyuW%akpm@linux-foundation.org> (raw)
In-Reply-To: <20210123210029.a7c704d0cab204683e41ad10@linux-foundation.org>
From: Xiaoming Ni <nixiaoming@huawei.com>
Subject: proc_sysctl: fix oops caused by incorrect command parameters
The process_sysctl_arg() does not check whether val is empty before
invoking strlen(val). If the command line parameter () is incorrectly
configured and val is empty, oops is triggered.
For example:
"hung_task_panic=1" is incorrectly written as "hung_task_panic", oops is
triggered. The call stack is as follows:
Kernel command line: .... hung_task_panic
......
Call trace:
__pi_strlen+0x10/0x98
parse_args+0x278/0x344
do_sysctl_args+0x8c/0xfc
kernel_init+0x5c/0xf4
ret_from_fork+0x10/0x30
To fix it, check whether "val" is empty when "phram" is a sysctl field.
Error codes are returned in the failure branch, and error logs are
generated by parse_args().
Link: https://lkml.kernel.org/r/20210118133029.28580-1-nixiaoming@huawei.com
Fixes: 3db978d480e2843 ("kernel/sysctl: support setting sysctl parameters from kernel command line")
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: <stable@vger.kernel.org> [5.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
fs/proc/proc_sysctl.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
--- a/fs/proc/proc_sysctl.c~proc_sysctl-fix-oops-caused-by-incorrect-command-parameters
+++ a/fs/proc/proc_sysctl.c
@@ -1770,6 +1770,12 @@ static int process_sysctl_arg(char *para
return 0;
}
+ if (!val)
+ return -EINVAL;
+ len = strlen(val);
+ if (len == 0)
+ return -EINVAL;
+
/*
* To set sysctl options, we use a temporary mount of proc, look up the
* respective sys/ file and write to it. To avoid mounting it when no
@@ -1811,7 +1817,6 @@ static int process_sysctl_arg(char *para
file, param, val);
goto out;
}
- len = strlen(val);
wret = kernel_write(file, val, len, &pos);
if (wret < 0) {
err = wret;
_
next prev parent reply other threads:[~2021-01-24 5:02 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-24 5:00 incoming Andrew Morton
2021-01-24 5:00 ` [patch 01/19] x86/setup: don't remove E820_TYPE_RAM for pfn 0 Andrew Morton
2021-01-24 5:01 ` [patch 02/19] mm: fix initialization of struct page for holes in memory layout Andrew Morton
2021-01-24 5:01 ` [patch 03/19] mm: memcg/slab: optimize objcg stock draining Andrew Morton
2021-01-24 5:01 ` [patch 04/19] mm: memcg: fix memcg file_dirty numa stat Andrew Morton
2021-01-24 5:01 ` [patch 05/19] mm: fix numa stats for thp migration Andrew Morton
2021-01-24 5:01 ` [patch 06/19] mm: memcontrol: prevent starvation when writing memory.high Andrew Morton
2021-01-24 18:01 ` Shakeel Butt
2021-01-24 18:35 ` Linus Torvalds
2021-01-24 5:01 ` [patch 07/19] kasan: fix unaligned address is unhandled in kasan_remove_zero_shadow Andrew Morton
2021-01-24 5:01 ` [patch 08/19] kasan: fix incorrect arguments passing in kasan_add_zero_shadow Andrew Morton
2021-01-24 5:01 ` [patch 09/19] kasan: fix HW_TAGS boot parameters Andrew Morton
2021-01-24 5:01 ` [patch 10/19] kasan, mm: fix conflicts with init_on_alloc/free Andrew Morton
2021-01-24 5:01 ` [patch 11/19] kasan, mm: fix resetting page_alloc tags for HW_TAGS Andrew Morton
2021-01-24 5:01 ` [patch 12/19] ubsan: disable unsigned-overflow check for i386 Andrew Morton
2021-01-24 5:01 ` [patch 13/19] mm: fix page reference leak in soft_offline_page() Andrew Morton
2021-01-24 5:01 ` [patch 14/19] sparc/mm/highmem: flush cache and TLB Andrew Morton
2021-01-24 5:02 ` [patch 15/19] mm/highmem: prepare for overriding set_pte_at() Andrew Morton
2021-01-24 5:02 ` [patch 16/19] mips/mm/highmem: use set_pte() for kmap_local() Andrew Morton
2021-01-24 5:02 ` [patch 17/19] powerpc/mm/highmem: use __set_pte_at() " Andrew Morton
2021-01-24 5:02 ` Andrew Morton [this message]
2021-01-24 5:02 ` [patch 19/19] MAINTAINERS: add a couple more files to the Clang/LLVM section Andrew Morton
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=20210124050216.W3v89CyuW%akpm@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=adobriyan@gmail.com \
--cc=hkallweit1@gmail.com \
--cc=keescook@chromium.org \
--cc=linux-mm@kvack.org \
--cc=mcgrof@kernel.org \
--cc=mhiramat@kernel.org \
--cc=mhocko@suse.com \
--cc=mm-commits@vger.kernel.org \
--cc=nixiaoming@huawei.com \
--cc=rdunlap@infradead.org \
--cc=stable@vger.kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=vbabka@suse.cz \
--cc=yzaikin@google.com \
/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).