/* * Seccomp BPF example using a macro-based generator. * * Copyright (c) 2012 The Chromium OS Authors * Author: Will Drewry * * The code may be used by anyone for any purpose, * and can serve as a starting point for developing * applications using prctl(PR_ATTACH_SECCOMP_FILTER). */ #include #include #include #include #include #include #include #include "bpf-helper.h" #ifndef PR_SET_NO_NEW_PRIVS #define PR_SET_NO_NEW_PRIVS 38 #endif int main(int argc, char **argv) { struct bpf_labels l = { .count = 0, }; static const char msg1[] = "Please type something: "; static const char msg2[] = "You typed: "; char buf[256]; struct sock_filter filter[] = { /* TODO: LOAD_SYSCALL_NR(arch) and enforce an arch */ LOAD_SYSCALL_NR, SYSCALL(__NR_exit, ALLOW), SYSCALL(__NR_exit_group, ALLOW), SYSCALL(__NR_write, JUMP(&l, write_fd)), SYSCALL(__NR_read, JUMP(&l, read)), DENY, /* Don't passthrough into a label */ LABEL(&l, read), ARG(0), JNE(STDIN_FILENO, DENY), ARG(1), JNE((unsigned long)buf, DENY), ARG(2), JGE(sizeof(buf), DENY), ALLOW, LABEL(&l, write_fd), ARG(0), JEQ(STDOUT_FILENO, JUMP(&l, write_buf)), JEQ(STDERR_FILENO, JUMP(&l, write_buf)), DENY, LABEL(&l, write_buf), ARG(1), JEQ((unsigned long)msg1, JUMP(&l, msg1_len)), JEQ((unsigned long)msg2, JUMP(&l, msg2_len)), JEQ((unsigned long)buf, JUMP(&l, buf_len)), DENY, LABEL(&l, msg1_len), ARG(2), JLT(sizeof(msg1), ALLOW), DENY, LABEL(&l, msg2_len), ARG(2), JLT(sizeof(msg2), ALLOW), DENY, LABEL(&l, buf_len), ARG(2), JLT(sizeof(buf), ALLOW), DENY, }; struct sock_fprog prog = { .filter = filter, .len = (unsigned short)(sizeof(filter)/sizeof(filter[0])), }; ssize_t bytes; bpf_resolve_jumps(&l, filter, sizeof(filter)/sizeof(*filter)); if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { perror("prctl(NO_NEW_PRIVS)"); return 1; } if (prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog)) { perror("prctl(SECCOMP)"); return 1; } syscall(__NR_write, STDOUT_FILENO, msg1, strlen(msg1)); bytes = syscall(__NR_read, STDIN_FILENO, buf, sizeof(buf)-1); bytes = (bytes > 0 ? bytes : 0); syscall(__NR_write, STDERR_FILENO, msg2, strlen(msg2)); syscall(__NR_write, STDERR_FILENO, buf, bytes); /* Now get killed */ syscall(__NR_write, STDERR_FILENO, msg2, strlen(msg2)+2); return 0; } e='id' value='a76a82a3e38c8d3fb6499e3dfaeb0949241ab588'/>
path: root/include/math-emu/soft-fp.h
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authorPeter Zijlstra <peterz@infradead.org>2017-01-26 16:39:55 +0100
committerIngo Molnar <mingo@kernel.org>2017-01-30 11:41:25 +0100
commita76a82a3e38c8d3fb6499e3dfaeb0949241ab588 (patch)
treeb5bc906278fe1ac66d75de984d26bf59b43b3ed8 /include/math-emu/soft-fp.h
parent566cf877a1fcb6d6dc0126b076aad062054c2637 (diff)
perf/core: Fix use-after-free bug
Dmitry reported a KASAN use-after-free on event->group_leader. It turns out there's a hole in perf_remove_from_context() due to event_function_call() not calling its function when the task associated with the event is already dead. In this case the event will have been detached from the task, but the grouping will have been retained, such that group operations might still work properly while there are live child events etc. This does however mean that we can miss a perf_group_detach() call when the group decomposes, this in turn can then lead to use-after-free. Fix it by explicitly doing the group detach if its still required. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org # v4.5+ Cc: syzkaller <syzkaller@googlegroups.com> Fixes: 63b6da39bb38 ("perf: Fix perf_event_exit_task() race") Link: http://lkml.kernel.org/r/20170126153955.GD6515@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/math-emu/soft-fp.h')