From: Baokun Li libaokun1@huawei.com

mainline inclusion from mainline-5.17-rc1 commit 1622ed7d0743201293094162c26019d2573ecacb category: bugfix bugzilla: 185873, https://gitee.com/openeuler/kernel/issues/I4MTTR CVE: NA

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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: Baokun Li libaokun1@huawei.com Reported-by: Hulk Robot hulkci@huawei.com Acked-by: Luis Chamberlain mcgrof@kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Baokun Li libaokun1@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- kernel/sysctl.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 35512e2ea8a34..31c35a65fbb78 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -3017,10 +3017,11 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int 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;