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| author | Kees Cook <keescook@chromium.org> | 2017-02-07 15:18:51 -0800 |
|---|---|---|
| committer | James Morris <james.l.morris@oracle.com> | 2017-02-23 09:42:35 +1100 |
| commit | d7276e321ff8a53106a59c85ca46d03e34288893 (patch) | |
| tree | e3b752b1b1a94ff0794e29e5658dfd48dd9b7d4d /kernel/seccomp.c | |
| parent | 37c85961c3f87f2141c84e53df31e59db072fd2e (diff) | |
| download | lwn-d7276e321ff8a53106a59c85ca46d03e34288893.tar.gz lwn-d7276e321ff8a53106a59c85ca46d03e34288893.zip | |
seccomp: Only dump core when single-threaded
The SECCOMP_RET_KILL filter return code has always killed the current
thread, not the entire process. Changing this as a side-effect of dumping
core isn't a safe thing to do (a few test suites have already flagged this
behavioral change). Instead, restore the RET_KILL semantics, but still
dump core when a RET_KILL delivers SIGSYS to a single-threaded process.
Fixes: b25e67161c29 ("seccomp: dump core when using SECCOMP_RET_KILL")
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Diffstat (limited to 'kernel/seccomp.c')
| -rw-r--r-- | kernel/seccomp.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/kernel/seccomp.c b/kernel/seccomp.c index f8f88ebcb3ba..e15185c28de5 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -643,11 +643,14 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd, default: { siginfo_t info; audit_seccomp(this_syscall, SIGSYS, action); - /* Show the original registers in the dump. */ - syscall_rollback(current, task_pt_regs(current)); - /* Trigger a manual coredump since do_exit skips it. */ - seccomp_init_siginfo(&info, this_syscall, data); - do_coredump(&info); + /* Dump core only if this is the last remaining thread. */ + if (get_nr_threads(current) == 1) { + /* Show the original registers in the dump. */ + syscall_rollback(current, task_pt_regs(current)); + /* Trigger a manual coredump since do_exit skips it. */ + seccomp_init_siginfo(&info, this_syscall, data); + do_coredump(&info); + } do_exit(SIGSYS); } } |