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authorLinus Torvalds <torvalds@linux-foundation.org>2021-11-10 16:15:54 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-11-10 16:15:54 -0800
commit5147da902e0dd162c6254a61e4c57f21b60a9b1c (patch)
tree862b1147d858f56d24193d7e5921436019066b00 /kernel/entry
parenta41b74451b35f7a6529689760eb8c05241feecbc (diff)
parentf91140e4553408cacd326624cd50fc367725e04a (diff)
Merge branch 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull exit cleanups from Eric Biederman: "While looking at some issues related to the exit path in the kernel I found several instances where the code is not using the existing abstractions properly. This set of changes introduces force_fatal_sig a way of sending a signal and not allowing it to be caught, and corrects the misuse of the existing abstractions that I found. A lot of the misuse of the existing abstractions are silly things such as doing something after calling a no return function, rolling BUG by hand, doing more work than necessary to terminate a kernel thread, or calling do_exit(SIGKILL) instead of calling force_sig(SIGKILL). In the review a deficiency in force_fatal_sig and force_sig_seccomp where ptrace or sigaction could prevent the delivery of the signal was found. I have added a change that adds SA_IMMUTABLE to change that makes it impossible to interrupt the delivery of those signals, and allows backporting to fix force_sig_seccomp And Arnd found an issue where a function passed to kthread_run had the wrong prototype, and after my cleanup was failing to build." * 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (23 commits) soc: ti: fix wkup_m3_rproc_boot_thread return type signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed signal: Replace force_sigsegv(SIGSEGV) with force_fatal_sig(SIGSEGV) exit/r8188eu: Replace the macro thread_exit with a simple return 0 exit/rtl8712: Replace the macro thread_exit with a simple return 0 exit/rtl8723bs: Replace the macro thread_exit with a simple return 0 signal/x86: In emulate_vsyscall force a signal instead of calling do_exit signal/sparc32: In setup_rt_frame and setup_fram use force_fatal_sig signal/sparc32: Exit with a fatal signal when try_to_clear_window_buffer fails exit/syscall_user_dispatch: Send ordinary signals on failure signal: Implement force_fatal_sig exit/kthread: Have kernel threads return instead of calling do_exit signal/s390: Use force_sigsegv in default_trap_handler signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved. signal/vm86_32: Replace open coded BUG_ON with an actual BUG_ON signal/sparc: In setup_tsb_params convert open coded BUG into BUG signal/powerpc: On swapcontext failure force SIGSEGV signal/sh: Use force_sig(SIGKILL) instead of do_group_exit(SIGKILL) signal/mips: Update (_save|_restore)_fp_context to fail with -EFAULT signal/sparc32: Remove unreachable do_exit in do_sparc_fault ...
Diffstat (limited to 'kernel/entry')
-rw-r--r--kernel/entry/syscall_user_dispatch.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/kernel/entry/syscall_user_dispatch.c b/kernel/entry/syscall_user_dispatch.c
index c240302f56e2..4508201847d2 100644
--- a/kernel/entry/syscall_user_dispatch.c
+++ b/kernel/entry/syscall_user_dispatch.c
@@ -47,14 +47,18 @@ bool syscall_user_dispatch(struct pt_regs *regs)
* access_ok() is performed once, at prctl time, when
* the selector is loaded by userspace.
*/
- if (unlikely(__get_user(state, sd->selector)))
- do_exit(SIGSEGV);
+ if (unlikely(__get_user(state, sd->selector))) {
+ force_fatal_sig(SIGSEGV);
+ return true;
+ }
if (likely(state == SYSCALL_DISPATCH_FILTER_ALLOW))
return false;
- if (state != SYSCALL_DISPATCH_FILTER_BLOCK)
- do_exit(SIGSYS);
+ if (state != SYSCALL_DISPATCH_FILTER_BLOCK) {
+ force_fatal_sig(SIGSYS);
+ return true;
+ }
}
sd->on_dispatch = true;