diff options
author | Joel Granados <j.granados@samsung.com> | 2023-11-21 12:02:18 +0100 |
---|---|---|
committer | Luis Chamberlain <mcgrof@kernel.org> | 2023-12-28 04:57:57 -0800 |
commit | 315552310c7de92baea4e570967066569937a843 (patch) | |
tree | 13c9a1058f695bb2b16b6dae36be99fe3ff92ccd /fs/proc | |
parent | 05c1a8d01facb9b24ab267929be94f9fc5ca686d (diff) |
sysctl: Fix out of bounds access for empty sysctl registers
When registering tables to the sysctl subsystem there is a check to see
if header is a permanently empty directory (used for mounts). This check
evaluates the first element of the ctl_table. This results in an out of
bounds evaluation when registering empty directories.
The function register_sysctl_mount_point now passes a ctl_table of size
1 instead of size 0. It now relies solely on the type to identify
a permanently empty register.
Make sure that the ctl_table has at least one element before testing for
permanent emptiness.
Signed-off-by: Joel Granados <j.granados@samsung.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202311201431.57aae8f3-oliver.sang@intel.com
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Diffstat (limited to 'fs/proc')
-rw-r--r-- | fs/proc/proc_sysctl.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 8064ea76f80b..84abf98340a0 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -44,7 +44,7 @@ static struct ctl_table sysctl_mount_point[] = { */ struct ctl_table_header *register_sysctl_mount_point(const char *path) { - return register_sysctl_sz(path, sysctl_mount_point, 0); + return register_sysctl(path, sysctl_mount_point); } EXPORT_SYMBOL(register_sysctl_mount_point); @@ -233,7 +233,8 @@ static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header) return -EROFS; /* Am I creating a permanently empty directory? */ - if (sysctl_is_perm_empty_ctl_table(header->ctl_table)) { + if (header->ctl_table_size > 0 && + sysctl_is_perm_empty_ctl_table(header->ctl_table)) { if (!RB_EMPTY_ROOT(&dir->root)) return -EINVAL; sysctl_set_perm_empty_ctl_header(dir_h); @@ -1213,6 +1214,10 @@ static bool get_links(struct ctl_dir *dir, struct ctl_table_header *tmp_head; struct ctl_table *entry, *link; + if (header->ctl_table_size == 0 || + sysctl_is_perm_empty_ctl_table(header->ctl_table)) + return true; + /* Are there links available for every entry in table? */ list_for_each_table_entry(entry, header) { const char *procname = entry->procname; |