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| author | Adam Tkac <vonsch@gmail.com> | 2008-10-15 22:01:45 -0700 | 
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-16 11:21:31 -0700 | 
| commit | 0c2d64fb6cae9aae480f6a46cfe79f8d7d48b59f (patch) | |
| tree | f0080c63a78a021cc3404e12e205e3b82e982427 | |
| parent | b4236f81f2347096df650fb072f50d67bb6066a2 (diff) | |
| download | olio-linux-3.10-0c2d64fb6cae9aae480f6a46cfe79f8d7d48b59f.tar.xz olio-linux-3.10-0c2d64fb6cae9aae480f6a46cfe79f8d7d48b59f.zip  | |
rlimit: permit setting RLIMIT_NOFILE to RLIM_INFINITY
When a process wants to set the limit of open files to RLIM_INFINITY it
gets EPERM even if it has CAP_SYS_RESOURCE capability.
For example, BIND does:
...
#elif defined(NR_OPEN) && defined(__linux__)
        /*
         * Some Linux kernels don't accept RLIM_INFINIT; the maximum
         * possible value is the NR_OPEN defined in linux/fs.h.
         */
        if (resource == isc_resource_openfiles && rlim_value == RLIM_INFINITY) {
                rl.rlim_cur = rl.rlim_max = NR_OPEN;
                unixresult = setrlimit(unixresource, &rl);
                if (unixresult == 0)
                        return (ISC_R_SUCCESS);
        }
#elif ...
If we allow setting RLIMIT_NOFILE to RLIM_INFINITY we increase portability
- you don't have to check if OS is linux and then use different schema for
limits.
The spec says "Specifying RLIM_INFINITY as any resource limit value on a
successful call to setrlimit() shall inhibit enforcement of that resource
limit." and we're presently not doing that.
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | kernel/sys.c | 16 | 
1 files changed, 12 insertions, 4 deletions
diff --git a/kernel/sys.c b/kernel/sys.c index 234d9454294..d5b79f65ad9 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1450,14 +1450,22 @@ asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)  		return -EINVAL;  	if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))  		return -EFAULT; -	if (new_rlim.rlim_cur > new_rlim.rlim_max) -		return -EINVAL;  	old_rlim = current->signal->rlim + resource;  	if ((new_rlim.rlim_max > old_rlim->rlim_max) &&  	    !capable(CAP_SYS_RESOURCE))  		return -EPERM; -	if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open) -		return -EPERM; + +	if (resource == RLIMIT_NOFILE) { +		if (new_rlim.rlim_max == RLIM_INFINITY) +			new_rlim.rlim_max = sysctl_nr_open; +		if (new_rlim.rlim_cur == RLIM_INFINITY) +			new_rlim.rlim_cur = sysctl_nr_open; +		if (new_rlim.rlim_max > sysctl_nr_open) +			return -EPERM; +	} + +	if (new_rlim.rlim_cur > new_rlim.rlim_max) +		return -EINVAL;  	retval = security_task_setrlimit(resource, &new_rlim);  	if (retval)  |