diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 4a3d70baa7f1..6791813cd439 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -191,6 +191,8 @@ LSM_HOOK(int, 0, kernel_post_read_file, struct file *file, char *buf, loff_t size, enum kernel_read_file_id id) LSM_HOOK(int, 0, task_fix_setuid, struct cred *new, const struct cred *old, int flags) +LSM_HOOK(int, 0, task_fix_setgid, struct cred *new, const struct cred * old, + int flags) LSM_HOOK(int, 0, task_setpgid, struct task_struct *p, pid_t pgid) LSM_HOOK(int, 0, task_getpgid, struct task_struct *p) LSM_HOOK(int, 0, task_getsid, struct task_struct *p) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 73d87955e26b..95b7c1d32062 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -659,6 +659,15 @@ * @old is the set of credentials that are being replaces * @flags contains one of the LSM_SETID_* values. * Return 0 on success. + * @task_fix_setgid: + * Update the module's state after setting one or more of the group + * identity attributes of the current process. The @flags parameter + * indicates which of the set*gid system calls invoked this hook. + * @new is the set of credentials that will be installed. Modifications + * should be made to this rather than to @current->cred. + * @old is the set of credentials that are being replaced. + * @flags contains one of the LSM_SETID_* values. + * Return 0 on success. * @task_setpgid: * Check permission before setting the process group identifier of the * process @p to @pgid. diff --git a/include/linux/security.h b/include/linux/security.h index 469fa91f8cf8..0a0a03b36a3b 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -392,6 +392,8 @@ int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, enum kernel_read_file_id id); int security_task_fix_setuid(struct cred *new, const struct cred *old, int flags); +int security_task_fix_setgid(struct cred *new, const struct cred *old, + int flags); int security_task_setpgid(struct task_struct *p, pid_t pgid); int security_task_getpgid(struct task_struct *p); int security_task_getsid(struct task_struct *p); @@ -1036,6 +1038,13 @@ static inline int security_task_fix_setuid(struct cred *new, return cap_task_fix_setuid(new, old, flags); } +static inline int security_task_fix_setgid(struct cred *new, + const struct cred *old, + int flags) +{ + return 0; +} + static inline int security_task_setpgid(struct task_struct *p, pid_t pgid) { return 0; diff --git a/kernel/sys.c b/kernel/sys.c index fd46865b46ba..00a96746e28a 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; } } diff --git a/security/security.c b/security/security.c index 2a652e59c413..0ce3e73edd42 100644 --- a/security/security.c +++ b/security/security.c @@ -1696,6 +1696,12 @@ int security_task_fix_setuid(struct cred *new, const struct cred *old, return call_int_hook(task_fix_setuid, 0, new, old, flags); } +int security_task_fix_setgid(struct cred *new, const struct cred *old, + int flags) +{ + return call_int_hook(task_fix_setgid, 0, new, old, flags); +} + int security_task_setpgid(struct task_struct *p, pid_t pgid) { return call_int_hook(task_setpgid, 0, p, pgid);