From 39030e1351aa1aa7443bb2da24426573077c83da Mon Sep 17 00:00:00 2001 From: Thomas Cedeno Date: Tue, 9 Jun 2020 10:22:13 -0700 Subject: security: Add LSM hooks to set*gid syscalls The SafeSetID LSM uses the security_task_fix_setuid hook to filter set*uid() syscalls according to its configured security policy. In preparation for adding analagous support in the LSM for set*gid() syscalls, we add the requisite hook here. Tested by putting print statements in the security_task_fix_setgid hook and seeing them get hit during kernel boot. Signed-off-by: Thomas Cedeno Signed-off-by: Micah Morton --- kernel/sys.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sys.c b/kernel/sys.c index d325f3ab624a..f5c06c48d585 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -393,6 +393,10 @@ long __sys_setregid(gid_t rgid, gid_t egid) new->sgid = new->egid; new->fsgid = new->egid; + retval = security_task_fix_setgid(new, old, LSM_SETID_RE); + if (retval < 0) + goto error; + return commit_creds(new); error: @@ -435,6 +439,10 @@ long __sys_setgid(gid_t gid) else goto error; + retval = security_task_fix_setgid(new, old, LSM_SETID_ID); + if (retval < 0) + goto error; + return commit_creds(new); error: @@ -756,6 +764,10 @@ long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) new->sgid = ksgid; new->fsgid = new->egid; + retval = security_task_fix_setgid(new, old, LSM_SETID_RES); + if (retval < 0) + goto error; + return commit_creds(new); error: @@ -862,7 +874,8 @@ long __sys_setfsgid(gid_t gid) ns_capable(old->user_ns, CAP_SETGID)) { if (!gid_eq(kgid, old->fsgid)) { new->fsgid = kgid; - goto change_okay; + if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0) + goto change_okay; } } -- cgit v1.2.3