Commit 1622ed7d authored by Baokun Li's avatar Baokun Li Committed by Linus Torvalds
Browse files

sysctl: returns -EINVAL when a negative value is passed to proc_doulongvec_minmax 

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.

Link: https://lkml.kernel.org/r/20211220092627.3744624-1-libaokun1@huawei.com


Signed-off-by: default avatarBaokun Li <libaokun1@huawei.com>
Reported-by: default avatarHulk Robot <hulkci@huawei.com>
Acked-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e565a8ed

kernel/sysctl.c

+4 −3
Original line number Diff line number Diff line
@@ -1145,10 +1145,11 @@ 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;