From: David Quigley Date: Fri, 30 Jun 2006 08:55:46 +0000 (-0700) Subject: [PATCH] SELinux: extend task_kill hook to handle signals sent by AIO completion X-Git-Tag: v2.6.18-rc1~297 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f9008e4c5c525941967b67777945aa6266ab6326;p=linux-2.6 [PATCH] SELinux: extend task_kill hook to handle signals sent by AIO completion This patch extends the security_task_kill hook to handle signals sent by AIO completion. In this case, the secid of the task responsible for the signal needs to be obtained and saved earlier, so a security_task_getsecid() hook is added, and then this saved value is passed subsequently to the extended task_kill hook for use in checking. Signed-off-by: David Quigley Signed-off-by: James Morris Cc: Stephen Smalley Cc: Chris Wright Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/include/linux/security.h b/include/linux/security.h index c7ea15716d..d4b13d617f 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -567,6 +567,9 @@ struct swap_info_struct; * @p. * @p contains the task_struct for the process. * Return 0 if permission is granted. + * @task_getsecid: + * Retrieve the security identifier of the process @p. + * @p contains the task_struct for the process and place is into @secid. * @task_setgroups: * Check permission before setting the supplementary group set of the * current process. @@ -615,6 +618,7 @@ struct swap_info_struct; * @p contains the task_struct for process. * @info contains the signal information. * @sig contains the signal value. + * @secid contains the sid of the process where the signal originated * Return 0 if permission is granted. * @task_wait: * Check permission before allowing a process to reap a child process @p @@ -1219,6 +1223,7 @@ struct security_operations { int (*task_setpgid) (struct task_struct * p, pid_t pgid); int (*task_getpgid) (struct task_struct * p); int (*task_getsid) (struct task_struct * p); + void (*task_getsecid) (struct task_struct * p, u32 * secid); int (*task_setgroups) (struct group_info *group_info); int (*task_setnice) (struct task_struct * p, int nice); int (*task_setioprio) (struct task_struct * p, int ioprio); @@ -1228,7 +1233,7 @@ struct security_operations { int (*task_getscheduler) (struct task_struct * p); int (*task_movememory) (struct task_struct * p); int (*task_kill) (struct task_struct * p, - struct siginfo * info, int sig); + struct siginfo * info, int sig, u32 secid); int (*task_wait) (struct task_struct * p); int (*task_prctl) (int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, @@ -1839,6 +1844,11 @@ static inline int security_task_getsid (struct task_struct *p) return security_ops->task_getsid (p); } +static inline void security_task_getsecid (struct task_struct *p, u32 *secid) +{ + security_ops->task_getsecid (p, secid); +} + static inline int security_task_setgroups (struct group_info *group_info) { return security_ops->task_setgroups (group_info); @@ -1878,9 +1888,10 @@ static inline int security_task_movememory (struct task_struct *p) } static inline int security_task_kill (struct task_struct *p, - struct siginfo *info, int sig) + struct siginfo *info, int sig, + u32 secid) { - return security_ops->task_kill (p, info, sig); + return security_ops->task_kill (p, info, sig, secid); } static inline int security_task_wait (struct task_struct *p) @@ -2491,6 +2502,9 @@ static inline int security_task_getsid (struct task_struct *p) return 0; } +static inline void security_task_getsecid (struct task_struct *p, u32 *secid) +{ } + static inline int security_task_setgroups (struct group_info *group_info) { return 0; @@ -2530,7 +2544,8 @@ static inline int security_task_movememory (struct task_struct *p) } static inline int security_task_kill (struct task_struct *p, - struct siginfo *info, int sig) + struct siginfo *info, int sig, + u32 secid) { return 0; } diff --git a/security/dummy.c b/security/dummy.c index 9135408085..de53f6eb0c 100644 --- a/security/dummy.c +++ b/security/dummy.c @@ -506,6 +506,9 @@ static int dummy_task_getsid (struct task_struct *p) return 0; } +static void dummy_task_getsecid (struct task_struct *p, u32 *secid) +{ } + static int dummy_task_setgroups (struct group_info *group_info) { return 0; @@ -548,7 +551,7 @@ static int dummy_task_wait (struct task_struct *p) } static int dummy_task_kill (struct task_struct *p, struct siginfo *info, - int sig) + int sig, u32 secid) { return 0; } @@ -981,6 +984,7 @@ void security_fixup_ops (struct security_operations *ops) set_to_dummy_if_null(ops, task_setpgid); set_to_dummy_if_null(ops, task_getpgid); set_to_dummy_if_null(ops, task_getsid); + set_to_dummy_if_null(ops, task_getsecid); set_to_dummy_if_null(ops, task_setgroups); set_to_dummy_if_null(ops, task_setnice); set_to_dummy_if_null(ops, task_setioprio); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index b85afcf385..a5189a3473 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2644,6 +2644,11 @@ static int selinux_task_getsid(struct task_struct *p) return task_has_perm(current, p, PROCESS__GETSESSION); } +static void selinux_task_getsecid(struct task_struct *p, u32 *secid) +{ + selinux_get_task_sid(p, secid); +} + static int selinux_task_setgroups(struct group_info *group_info) { /* See the comment for setuid above. */ @@ -2700,12 +2705,14 @@ static int selinux_task_movememory(struct task_struct *p) return task_has_perm(current, p, PROCESS__SETSCHED); } -static int selinux_task_kill(struct task_struct *p, struct siginfo *info, int sig) +static int selinux_task_kill(struct task_struct *p, struct siginfo *info, + int sig, u32 secid) { u32 perm; int rc; + struct task_security_struct *tsec; - rc = secondary_ops->task_kill(p, info, sig); + rc = secondary_ops->task_kill(p, info, sig, secid); if (rc) return rc; @@ -2716,8 +2723,12 @@ static int selinux_task_kill(struct task_struct *p, struct siginfo *info, int si perm = PROCESS__SIGNULL; /* null signal; existence test */ else perm = signal_to_av(sig); - - return task_has_perm(current, p, perm); + tsec = p->security; + if (secid) + rc = avc_has_perm(secid, tsec->sid, SECCLASS_PROCESS, perm, NULL); + else + rc = task_has_perm(current, p, perm); + return rc; } static int selinux_task_prctl(int option, @@ -4434,6 +4445,7 @@ static struct security_operations selinux_ops = { .task_setpgid = selinux_task_setpgid, .task_getpgid = selinux_task_getpgid, .task_getsid = selinux_task_getsid, + .task_getsecid = selinux_task_getsecid, .task_setgroups = selinux_task_setgroups, .task_setnice = selinux_task_setnice, .task_setioprio = selinux_task_setioprio,