[PATCH] setrlimit incorrectly allows hard limits to exceed soft limits

Kingsley Cheung
2002-11-11T04:03:44Z

Hi,

In 2.4.19 (also 2.5.46) setrlimit code only ever makes a comparison to
check the old soft limit with the new soft limit and the new hard
limit with the old hard limit. There is never a check to ensure the
new soft limit never exceeds the new hard limit.

Just try "ulimit -H -m 10000" for memory limits that were not
previously set. You end up with (hard limit = 10000) < (soft limit =
unlimited).

Fix is trivial.

--- sys.c Sat Aug 3 10:39:46 2002
+++ edited.sys.c Mon Nov 11 14:49:19 2002
@@ -1118,6 +1118,8 @@

if (resource >= RLIM_NLIMITS)
return -EINVAL;
+ if (new_rlim.rlim_cur > new_rlim.rlim_max)
+ return -EINVAL;
if(copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
return -EFAULT;
old_rlim = current->rlim + resource;

--
Kingsley