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authorEric W. Biederman <ebiederm@xmission.com>2012-01-21 10:03:13 -0800
committerEric W. Biederman <ebiederm@xmission.com>2012-01-24 16:37:55 -0800
commitf05e53a7fbb28c951c0c8cf3963fa8019ae1d4d3 (patch)
treeaa8f66eb061b79be46619cfe7717bd64663cee1b /fs/proc/proc_sysctl.c
parentbd295b56cfae85f2dd6c2b03951480c91e6d08f3 (diff)
sysctl: Create local copies of directory names used in paths
Creating local copies of directory names is a good idea for two reasons. - The dynamic names used by callers must be copied into new strings by the callers today to ensure the strings do not change between register and unregister of the sysctl table. - Sysctl directories have a potentially different lifetime than the time between register and unregister of any particular sysctl table. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'fs/proc/proc_sysctl.c')
-rw-r--r--fs/proc/proc_sysctl.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 86d32a318e2..bcf60fb8dce 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -943,10 +943,12 @@ struct ctl_table_header *__register_sysctl_paths(
struct ctl_table *new, **prevp;
unsigned int n, npath;
struct ctl_table_set *set;
+ size_t path_bytes = 0;
+ char *new_name;
/* Count the path components */
for (npath = 0; path[npath].procname; ++npath)
- ;
+ path_bytes += strlen(path[npath].procname) + 1;
/*
* For each path component, allocate a 2-element ctl_table array.
@@ -956,24 +958,27 @@ struct ctl_table_header *__register_sysctl_paths(
* We allocate everything in one go so that we don't have to
* worry about freeing additional memory in unregister_sysctl_table.
*/
- header = kzalloc(sizeof(struct ctl_table_header) +
+ header = kzalloc(sizeof(struct ctl_table_header) + path_bytes +
(2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
if (!header)
return NULL;
new = (struct ctl_table *) (header + 1);
+ new_name = (char *)(new + (2 * npath));
/* Now connect the dots */
prevp = &header->ctl_table;
for (n = 0; n < npath; ++n, ++path) {
/* Copy the procname */
- new->procname = path->procname;
+ strcpy(new_name, path->procname);
+ new->procname = new_name;
new->mode = 0555;
*prevp = new;
prevp = &new->child;
new += 2;
+ new_name += strlen(new_name) + 1;
}
*prevp = table;
header->ctl_table_arg = table;