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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-22 07:27:36 +0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-22 07:27:36 +0400 |
commit | cb60e3e65c1b96a4d6444a7a13dc7dd48bc15a2b (patch) | |
tree | 4322be35db678f6299348a76ad60a2023954af7d /samples/seccomp/bpf-fancy.c | |
parent | 99262a3dafa3290866512ddfb32609198f8973e9 (diff) | |
parent | ff2bb047c4bce9742e94911eeb44b4d6ff4734ab (diff) | |
download | linux-cb60e3e65c1b96a4d6444a7a13dc7dd48bc15a2b.tar.xz |
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
"New notable features:
- The seccomp work from Will Drewry
- PR_{GET,SET}_NO_NEW_PRIVS from Andy Lutomirski
- Longer security labels for Smack from Casey Schaufler
- Additional ptrace restriction modes for Yama by Kees Cook"
Fix up trivial context conflicts in arch/x86/Kconfig and include/linux/filter.h
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (65 commits)
apparmor: fix long path failure due to disconnected path
apparmor: fix profile lookup for unconfined
ima: fix filename hint to reflect script interpreter name
KEYS: Don't check for NULL key pointer in key_validate()
Smack: allow for significantly longer Smack labels v4
gfp flags for security_inode_alloc()?
Smack: recursive tramsmute
Yama: replace capable() with ns_capable()
TOMOYO: Accept manager programs which do not start with / .
KEYS: Add invalidation support
KEYS: Do LRU discard in full keyrings
KEYS: Permit in-place link replacement in keyring list
KEYS: Perform RCU synchronisation on keys prior to key destruction
KEYS: Announce key type (un)registration
KEYS: Reorganise keys Makefile
KEYS: Move the key config into security/keys/Kconfig
KEYS: Use the compat keyctl() syscall wrapper on Sparc64 for Sparc32 compat
Yama: remove an unused variable
samples/seccomp: fix dependencies on arch macros
Yama: add additional ptrace scopes
...
Diffstat (limited to 'samples/seccomp/bpf-fancy.c')
-rw-r--r-- | samples/seccomp/bpf-fancy.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/samples/seccomp/bpf-fancy.c b/samples/seccomp/bpf-fancy.c new file mode 100644 index 000000000000..8eb483aaec46 --- /dev/null +++ b/samples/seccomp/bpf-fancy.c @@ -0,0 +1,102 @@ +/* + * Seccomp BPF example using a macro-based generator. + * + * Copyright (c) 2012 The Chromium OS Authors <chromium-os-dev@chromium.org> + * Author: Will Drewry <wad@chromium.org> + * + * 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 <linux/filter.h> +#include <linux/seccomp.h> +#include <linux/unistd.h> +#include <stdio.h> +#include <string.h> +#include <sys/prctl.h> +#include <unistd.h> + +#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; + 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; +} |