From 8cf7630b29701d364f8df4a50e4f1f5e752b2778 Mon Sep 17 00:00:00 2001 From: Zev Weiss Date: Mon, 11 Mar 2019 23:28:02 -0700 Subject: [PATCH] kernel/sysctl.c: add missing range check in do_proc_dointvec_minmax_conv This bug has apparently existed since the introduction of this function in the pre-git era (4500e91754d3 in Thomas Gleixner's history.git, "[NET]: Add proc_dointvec_userhz_jiffies, use it for proper handling of neighbour sysctls."). As a minimal fix we can simply duplicate the corresponding check in do_proc_dointvec_conv(). Link: http://lkml.kernel.org/r/20190207123426.9202-3-zev@bewilderbeest.net Signed-off-by: Zev Weiss Cc: Brendan Higgins Cc: Iurii Zaikin Cc: Kees Cook Cc: Luis Chamberlain Cc: [2.6.2+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 7bb3988425ee..0854197e0e67 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2645,7 +2645,16 @@ static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp, { struct do_proc_dointvec_minmax_conv_param *param = data; if (write) { - int val = *negp ? -*lvalp : *lvalp; + int val; + if (*negp) { + if (*lvalp > (unsigned long) INT_MAX + 1) + return -EINVAL; + val = -*lvalp; + } else { + if (*lvalp > (unsigned long) INT_MAX) + return -EINVAL; + val = *lvalp; + } if ((param->min && *param->min > val) || (param->max && *param->max < val)) return -EINVAL;