From 70da2340fbc68e91e701762f785479ab495a0869 Mon Sep 17 00:00:00 2001 From: Amerigo Wang Date: Mon, 14 Dec 2009 17:59:52 -0800 Subject: [PATCH] 'sysctl_max_map_count' should be non-negative Jan Engelhardt reported we have this problem: setting max_map_count to a value large enough results in programs dying at first try. This is on 2.6.31.6: 15:59 borg:/proc/sys/vm # echo $[1<<31-1] >max_map_count 15:59 borg:/proc/sys/vm # cat max_map_count 1073741824 15:59 borg:/proc/sys/vm # echo $[1<<31] >max_map_count 15:59 borg:/proc/sys/vm # cat max_map_count Killed This is because we have a chance to make 'max_map_count' negative. but it's meaningless. Make it only accept non-negative values. Reported-by: Jan Engelhardt Signed-off-by: WANG Cong Cc: Ingo Molnar Cc: Peter Zijlstra Cc: James Morris Cc: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 60fc93131095..45e4bef0012a 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1131,7 +1131,8 @@ static struct ctl_table vm_table[] = { .data = &sysctl_max_map_count, .maxlen = sizeof(sysctl_max_map_count), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec, + .extra1 = &zero, }, #else { -- 2.20.1