When we pass a negative value to the proc_doulongvec_minmax() function, the function returns 0, but the corresponding interface value does not change. we can easily reproduce this problem with the following commands: `cd /proc/sys/fs/epoll` `echo -1 > max_user_watches; echo $?; cat max_user_watches` This function requires a non-negative number to be passed in, so when a negative number is passed in, -EINVAL is returned. Reported-by: Hulk Robot <hulkci@xxxxxxxxxx> Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx> --- V1->V2: Modify the judgment position. kernel/sysctl.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 7f07b058b180..4211e39a5fd3 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1147,10 +1147,11 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, err = proc_get_long(&p, &left, &val, &neg, proc_wspace_sep, sizeof(proc_wspace_sep), NULL); - if (err) + if (err || neg) { + err = -EINVAL; break; - if (neg) - continue; + } + val = convmul * val / convdiv; if ((min && val < *min) || (max && val > *max)) { err = -EINVAL; -- 2.31.1