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authorCheng Lin <cheng.lin130@zte.com.cn>2019-01-04 02:26:13 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-01-05 00:13:45 +0300
commit09be178400829dddc1189b50a7888495dd26aa84 (patch)
treed348e4d50c5dea50864bbf71613b2d44514a656c
parentafe922c2daae4a8f0101a30658c886c2b6eb2a96 (diff)
downloadlinux-09be178400829dddc1189b50a7888495dd26aa84.tar.xz
proc/sysctl: fix return error for proc_doulongvec_minmax()
If the number of input parameters is less than the total parameters, an EINVAL error will be returned. For example, we use proc_doulongvec_minmax to pass up to two parameters with kern_table: { .procname = "monitor_signals", .data = &monitor_sigs, .maxlen = 2*sizeof(unsigned long), .mode = 0644, .proc_handler = proc_doulongvec_minmax, }, Reproduce: When passing two parameters, it's work normal. But passing only one parameter, an error "Invalid argument"(EINVAL) is returned. [root@cl150 ~]# echo 1 2 > /proc/sys/kernel/monitor_signals [root@cl150 ~]# cat /proc/sys/kernel/monitor_signals 1 2 [root@cl150 ~]# echo 3 > /proc/sys/kernel/monitor_signals -bash: echo: write error: Invalid argument [root@cl150 ~]# echo $? 1 [root@cl150 ~]# cat /proc/sys/kernel/monitor_signals 3 2 [root@cl150 ~]# The following is the result after apply this patch. No error is returned when the number of input parameters is less than the total parameters. [root@cl150 ~]# echo 1 2 > /proc/sys/kernel/monitor_signals [root@cl150 ~]# cat /proc/sys/kernel/monitor_signals 1 2 [root@cl150 ~]# echo 3 > /proc/sys/kernel/monitor_signals [root@cl150 ~]# echo $? 0 [root@cl150 ~]# cat /proc/sys/kernel/monitor_signals 3 2 [root@cl150 ~]# There are three processing functions dealing with digital parameters, __do_proc_dointvec/__do_proc_douintvec/__do_proc_doulongvec_minmax. This patch deals with __do_proc_doulongvec_minmax, just as __do_proc_dointvec does, adding a check for parameters 'left'. In __do_proc_douintvec, its code implementation explicitly does not support multiple inputs. static int __do_proc_douintvec(...){ ... /* * Arrays are not supported, keep this simple. *Do not* add * support for them. */ if (vleft != 1) { *lenp = 0; return -EINVAL; } ... } So, just __do_proc_doulongvec_minmax has the problem. And most use of proc_doulongvec_minmax/proc_doulongvec_ms_jiffies_minmax just have one parameter. Link: http://lkml.kernel.org/r/1544081775-15720-1-git-send-email-cheng.lin130@zte.com.cn Signed-off-by: Cheng Lin <cheng.lin130@zte.com.cn> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--kernel/sysctl.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 1825f712e73b..7f6c1a3b3485 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2787,6 +2787,8 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
bool neg;
left -= proc_skip_spaces(&p);
+ if (!left)
+ break;
err = proc_get_long(&p, &left, &val, &neg,
proc_wspace_sep,