From: ebiederm@xmission.com (Eric W. Biederman)
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
Michael Schmitz <schmitzmic@gmail.com>,
linux-arch <linux-arch@vger.kernel.org>,
Jens Axboe <axboe@kernel.dk>, Oleg Nesterov <oleg@redhat.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Richard Henderson <rth@twiddle.net>,
Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
Matt Turner <mattst88@gmail.com>,
alpha <linux-alpha@vger.kernel.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
linux-m68k <linux-m68k@lists.linux-m68k.org>,
Arnd Bergmann <arnd@kernel.org>,
Ley Foon Tan <ley.foon.tan@intel.com>, Tejun Heo <tj@kernel.org>,
Kees Cook <keescook@chromium.org>
Subject: [PATCH 2/9] signal/seccomp: Refactor seccomp signal and coredump generation
Date: Thu, 24 Jun 2021 13:59:55 -0500 [thread overview]
Message-ID: <87r1gr6qc4.fsf_-_@disp2133> (raw)
In-Reply-To: <875yy3850g.fsf_-_@disp2133> (Eric W. Biederman's message of "Thu, 24 Jun 2021 13:57:35 -0500")
Factor out force_sig_seccomp from the seccomp signal generation and
place it in kernel/signal.c. The function force_sig_seccomp takes a
paramter force_coredump to indicate that the sigaction field should be
reset to SIGDFL so that a coredump will be generated when the signal
is delivered.
force_sig_seccomp is then used to replace both seccomp_send_sigsys
and seccomp_init_siginfo.
force_sig_info_to_task gains an extra parameter to force using
the default signal action.
With this change seccomp is no longer a special case and there
becomes exactly one place do_coredump is called from.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
include/linux/sched/signal.h | 1 +
kernel/seccomp.c | 43 ++++++++----------------------------
kernel/signal.c | 30 +++++++++++++++++++++----
3 files changed, 36 insertions(+), 38 deletions(-)
diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index 7f4278fa21fe..774be5d3ac3e 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -329,6 +329,7 @@ int force_sig_pkuerr(void __user *addr, u32 pkey);
int force_sig_perf(void __user *addr, u32 type, u64 sig_data);
int force_sig_ptrace_errno_trap(int errno, void __user *addr);
+int force_sig_seccomp(int syscall, int reason, bool force_coredump);
extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
extern void force_sigsegv(int sig);
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 6ecd3f3a52b5..3e06d4628d98 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -920,30 +920,6 @@ void get_seccomp_filter(struct task_struct *tsk)
refcount_inc(&orig->users);
}
-static void seccomp_init_siginfo(kernel_siginfo_t *info, int syscall, int reason)
-{
- clear_siginfo(info);
- info->si_signo = SIGSYS;
- info->si_code = SYS_SECCOMP;
- info->si_call_addr = (void __user *)KSTK_EIP(current);
- info->si_errno = reason;
- info->si_arch = syscall_get_arch(current);
- info->si_syscall = syscall;
-}
-
-/**
- * seccomp_send_sigsys - signals the task to allow in-process syscall emulation
- * @syscall: syscall number to send to userland
- * @reason: filter-supplied reason code to send to userland (via si_errno)
- *
- * Forces a SIGSYS with a code of SYS_SECCOMP and related sigsys info.
- */
-static void seccomp_send_sigsys(int syscall, int reason)
-{
- struct kernel_siginfo info;
- seccomp_init_siginfo(&info, syscall, reason);
- force_sig_info(&info);
-}
#endif /* CONFIG_SECCOMP_FILTER */
/* For use with seccomp_actions_logged */
@@ -1195,7 +1171,7 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
/* Show the handler the original registers. */
syscall_rollback(current, current_pt_regs());
/* Let the filter pass back 16 bits of data. */
- seccomp_send_sigsys(this_syscall, data);
+ force_sig_seccomp(this_syscall, data, false);
goto skip;
case SECCOMP_RET_TRACE:
@@ -1266,18 +1242,17 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
/* Dump core only if this is the last remaining thread. */
if (action != SECCOMP_RET_KILL_THREAD ||
get_nr_threads(current) == 1) {
- kernel_siginfo_t info;
-
/* Show the original registers in the dump. */
syscall_rollback(current, current_pt_regs());
- /* Trigger a manual coredump since do_exit skips it. */
- seccomp_init_siginfo(&info, this_syscall, data);
- do_coredump(&info);
+ /* Trigger a coredump with SIGSYS */
+ force_sig_seccomp(this_syscall, data, true);
+ } else {
+ if (action == SECCOMP_RET_KILL_THREAD)
+ do_exit(SIGSYS);
+ else
+ do_group_exit(SIGSYS);
}
- if (action == SECCOMP_RET_KILL_THREAD)
- do_exit(SIGSYS);
- else
- do_group_exit(SIGSYS);
+ return -1;
}
unreachable();
diff --git a/kernel/signal.c b/kernel/signal.c
index f7c6ffcbd044..da37cc4515f2 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -54,6 +54,7 @@
#include <asm/unistd.h>
#include <asm/siginfo.h>
#include <asm/cacheflush.h>
+#include <asm/syscall.h> /* for syscall_get_* */
/*
* SLAB caches for signal bits.
@@ -1349,7 +1350,7 @@ int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p
* that is why we also clear SIGNAL_UNKILLABLE.
*/
static int
-force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t)
+force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, bool sigdfl)
{
unsigned long int flags;
int ret, blocked, ignored;
@@ -1360,7 +1361,7 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t)
action = &t->sighand->action[sig-1];
ignored = action->sa.sa_handler == SIG_IGN;
blocked = sigismember(&t->blocked, sig);
- if (blocked || ignored) {
+ if (blocked || ignored || sigdfl) {
action->sa.sa_handler = SIG_DFL;
if (blocked) {
sigdelset(&t->blocked, sig);
@@ -1381,7 +1382,7 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t)
int force_sig_info(struct kernel_siginfo *info)
{
- return force_sig_info_to_task(info, current);
+ return force_sig_info_to_task(info, current, false);
}
/*
@@ -1712,7 +1713,7 @@ int force_sig_fault_to_task(int sig, int code, void __user *addr
info.si_flags = flags;
info.si_isr = isr;
#endif
- return force_sig_info_to_task(&info, t);
+ return force_sig_info_to_task(&info, t, false);
}
int force_sig_fault(int sig, int code, void __user *addr
@@ -1820,6 +1821,27 @@ int force_sig_perf(void __user *addr, u32 type, u64 sig_data)
return force_sig_info(&info);
}
+/**
+ * force_sig_seccomp - signals the task to allow in-process syscall emulation
+ * @syscall: syscall number to send to userland
+ * @reason: filter-supplied reason code to send to userland (via si_errno)
+ *
+ * Forces a SIGSYS with a code of SYS_SECCOMP and related sigsys info.
+ */
+int force_sig_seccomp(int syscall, int reason, bool force_coredump)
+{
+ struct kernel_siginfo info;
+
+ clear_siginfo(&info);
+ info.si_signo = SIGSYS;
+ info.si_code = SYS_SECCOMP;
+ info.si_call_addr = (void __user *)KSTK_EIP(current);
+ info.si_errno = reason;
+ info.si_arch = syscall_get_arch(current);
+ info.si_syscall = syscall;
+ return force_sig_info_to_task(&info, current, force_coredump);
+}
+
/* For the crazy architectures that include trap information in
* the errno field, instead of an actual errno value.
*/
--
2.20.1
next prev parent reply other threads:[~2021-06-24 19:00 UTC|newest]
Thread overview: 112+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-10 20:57 Kernel stack read with PTRACE_EVENT_EXIT and io_uring threads Eric W. Biederman
2021-06-10 22:04 ` Linus Torvalds
2021-06-11 21:39 ` Eric W. Biederman
2021-06-11 23:26 ` Linus Torvalds
2021-06-13 21:54 ` Eric W. Biederman
2021-06-13 22:18 ` Linus Torvalds
2021-06-14 2:05 ` Michael Schmitz
2021-06-14 5:03 ` Michael Schmitz
2021-06-14 16:26 ` Eric W. Biederman
2021-06-14 22:26 ` Michael Schmitz
2021-06-15 19:30 ` Eric W. Biederman
2021-06-15 19:36 ` [PATCH] alpha: Add extra switch_stack frames in exit, exec, and kernel threads Eric W. Biederman
2021-06-15 22:02 ` Linus Torvalds
2021-06-16 16:32 ` Eric W. Biederman
2021-06-16 18:29 ` [PATCH 0/2] alpha/ptrace: Improved switch_stack handling Eric W. Biederman
2021-06-16 18:31 ` [PATCH 1/2] alpha/ptrace: Record and handle the absence of switch_stack Eric W. Biederman
2021-06-16 20:00 ` Linus Torvalds
2021-06-16 20:37 ` Linus Torvalds
2021-06-16 20:57 ` Eric W. Biederman
2021-06-16 21:02 ` Al Viro
2021-06-16 21:08 ` Linus Torvalds
2021-06-16 20:42 ` Eric W. Biederman
2021-06-16 20:17 ` Al Viro
2021-06-21 2:01 ` Michael Schmitz
2021-06-21 2:17 ` Linus Torvalds
2021-06-21 3:18 ` Michael Schmitz
2021-06-21 3:37 ` Linus Torvalds
2021-06-21 4:08 ` Michael Schmitz
2021-06-21 3:44 ` Al Viro
2021-06-21 5:31 ` Michael Schmitz
2021-06-21 2:27 ` Al Viro
2021-06-21 3:36 ` Michael Schmitz
2021-06-16 18:32 ` [PATCH 2/2] alpha/ptrace: Add missing switch_stack frames Eric W. Biederman
2021-06-16 20:25 ` Al Viro
2021-06-16 20:28 ` Al Viro
2021-06-16 20:49 ` Eric W. Biederman
2021-06-16 20:54 ` Al Viro
2021-06-16 20:47 ` Eric W. Biederman
2021-06-16 20:55 ` Al Viro
2021-06-16 20:50 ` [PATCH] alpha: Add extra switch_stack frames in exit, exec, and kernel threads Al Viro
2021-06-15 20:56 ` Kernel stack read with PTRACE_EVENT_EXIT and io_uring threads Michael Schmitz
2021-06-16 0:23 ` Finn Thain
2021-06-15 21:58 ` Linus Torvalds
2021-06-16 15:06 ` Eric W. Biederman
2021-06-21 13:54 ` Al Viro
2021-06-21 14:16 ` Al Viro
2021-06-21 16:50 ` Eric W. Biederman
2021-06-21 23:05 ` Al Viro
2021-06-22 16:39 ` Eric W. Biederman
2021-06-21 15:38 ` Linus Torvalds
2021-06-21 18:59 ` Al Viro
2021-06-21 19:22 ` Linus Torvalds
2021-06-21 19:45 ` Al Viro
2021-06-21 23:14 ` Linus Torvalds
2021-06-21 23:23 ` Al Viro
2021-06-21 23:36 ` Linus Torvalds
2021-06-22 21:02 ` Eric W. Biederman
2021-06-22 21:48 ` Michael Schmitz
2021-06-23 5:26 ` Michael Schmitz
2021-06-23 14:36 ` Eric W. Biederman
2021-06-22 0:01 ` Michael Schmitz
2021-06-22 20:04 ` Michael Schmitz
2021-06-22 20:18 ` Al Viro
2021-06-22 21:57 ` Michael Schmitz
2021-06-21 20:03 ` Eric W. Biederman
2021-06-21 23:15 ` Linus Torvalds
2021-06-22 20:52 ` Eric W. Biederman
2021-06-23 0:41 ` Linus Torvalds
2021-06-23 14:33 ` Eric W. Biederman
2021-06-24 18:57 ` [PATCH 0/9] Refactoring exit Eric W. Biederman
2021-06-24 18:59 ` [PATCH 1/9] signal/sh: Use force_sig(SIGKILL) instead of do_group_exit(SIGKILL) Eric W. Biederman
2021-06-24 18:59 ` Eric W. Biederman [this message]
2021-06-26 3:17 ` [PATCH 2/9] signal/seccomp: Refactor seccomp signal and coredump generation Kees Cook
2021-06-28 19:21 ` Eric W. Biederman
2021-06-28 14:34 ` [signal/seccomp] 3fdd8c68c2: kernel-selftests.seccomp.seccomp_bpf.fail kernel test robot
2021-06-24 19:00 ` [PATCH 3/9] signal/seccomp: Dump core when there is only one live thread Eric W. Biederman
2021-06-26 3:20 ` Kees Cook
2021-06-24 19:01 ` [PATCH 4/9] signal: Factor start_group_exit out of complete_signal Eric W. Biederman
2021-06-24 20:04 ` Linus Torvalds
2021-06-25 8:47 ` kernel test robot
2021-06-26 3:24 ` Kees Cook
2021-06-24 19:01 ` [PATCH 5/9] signal/group_exit: Use start_group_exit in place of do_group_exit Eric W. Biederman
2021-06-26 3:35 ` Kees Cook
2021-06-24 19:02 ` [PATCH 6/9] signal: Fold do_group_exit into get_signal fixing io_uring threads Eric W. Biederman
2021-06-26 3:42 ` Kees Cook
2021-06-28 19:25 ` Eric W. Biederman
2021-06-24 19:02 ` [PATCH 7/9] signal: Make individual tasks exiting a first class concept Eric W. Biederman
2021-06-24 20:11 ` Linus Torvalds
2021-06-24 21:37 ` Eric W. Biederman
2021-06-24 19:03 ` [PATCH 8/9] signal/task_exit: Use start_task_exit in place of do_exit Eric W. Biederman
2021-06-26 5:56 ` Kees Cook
2021-06-24 19:03 ` [PATCH 9/9] signal: Move PTRACE_EVENT_EXIT into get_signal Eric W. Biederman
2021-06-24 22:45 ` [PATCH 0/9] Refactoring exit Al Viro
2021-06-27 22:13 ` Al Viro
2021-06-27 22:59 ` Michael Schmitz
2021-06-28 7:31 ` Geert Uytterhoeven
2021-06-28 16:20 ` Eric W. Biederman
2021-06-28 17:14 ` Michael Schmitz
2021-06-28 19:17 ` Geert Uytterhoeven
2021-06-28 20:13 ` Michael Schmitz
2021-06-28 21:18 ` Geert Uytterhoeven
2021-06-28 23:42 ` Michael Schmitz
2021-06-29 20:28 ` [CFT][PATCH] exit/bdflush: Remove the deprecated bdflush system call Eric W. Biederman
2021-06-29 21:45 ` Michael Schmitz
2021-06-30 8:24 ` Geert Uytterhoeven
2021-06-30 8:37 ` Arnd Bergmann
2021-06-30 12:30 ` Cyril Hrubis
2021-06-28 19:02 ` [PATCH 0/9] Refactoring exit Eric W. Biederman
2021-06-21 19:24 ` Kernel stack read with PTRACE_EVENT_EXIT and io_uring threads Al Viro
2021-06-21 23:24 ` Michael Schmitz
2021-06-16 7:38 ` Geert Uytterhoeven
2021-06-16 19:40 ` Michael Schmitz
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