diff options
Diffstat (limited to 'fs/coredump.c')
| -rw-r--r-- | fs/coredump.c | 80 |
1 files changed, 67 insertions, 13 deletions
diff --git a/fs/coredump.c b/fs/coredump.c index a6b3c196cdef..1c060c0a2d72 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -41,6 +41,7 @@ #include <linux/fs.h> #include <linux/path.h> #include <linux/timekeeping.h> +#include <linux/sysctl.h> #include <linux/uaccess.h> #include <asm/mmu_context.h> @@ -52,9 +53,9 @@ #include <trace/events/sched.h> -int core_uses_pid; -unsigned int core_pipe_limit; -char core_pattern[CORENAME_MAX_SIZE] = "core"; +static int core_uses_pid; +static unsigned int core_pipe_limit; +static char core_pattern[CORENAME_MAX_SIZE] = "core"; static int core_name_size = CORENAME_MAX_SIZE; struct core_name { @@ -62,8 +63,6 @@ struct core_name { int used, size; }; -/* The maximal length of core_pattern is also specified in sysctl.c */ - static int expand_corename(struct core_name *cn, int size) { char *corename = krealloc(cn->corename, size, GFP_KERNEL); @@ -347,13 +346,13 @@ out: return ispipe; } -static int zap_process(struct task_struct *start, int exit_code, int flags) +static int zap_process(struct task_struct *start, int exit_code) { struct task_struct *t; int nr = 0; /* ignore all signals except SIGKILL, see prepare_signal() */ - start->signal->flags = SIGNAL_GROUP_COREDUMP | flags; + start->signal->flags = SIGNAL_GROUP_EXIT; start->signal->group_exit_code = exit_code; start->signal->group_stop_count = 0; @@ -372,13 +371,13 @@ static int zap_process(struct task_struct *start, int exit_code, int flags) static int zap_threads(struct task_struct *tsk, struct core_state *core_state, int exit_code) { + struct signal_struct *signal = tsk->signal; int nr = -EAGAIN; spin_lock_irq(&tsk->sighand->siglock); - if (!signal_group_exit(tsk->signal)) { - tsk->signal->core_state = core_state; - tsk->signal->group_exit_task = tsk; - nr = zap_process(tsk, exit_code, 0); + if (!(signal->flags & SIGNAL_GROUP_EXIT) && !signal->group_exec_task) { + signal->core_state = core_state; + nr = zap_process(tsk, exit_code); clear_tsk_thread_flag(tsk, TIF_SIGPENDING); tsk->flags |= PF_DUMPCORE; atomic_set(&core_state->nr_threads, nr); @@ -426,8 +425,6 @@ static void coredump_finish(bool core_dumped) spin_lock_irq(¤t->sighand->siglock); if (core_dumped && !__fatal_signal_pending(current)) current->signal->group_exit_code |= 0x80; - current->signal->group_exit_task = NULL; - current->signal->flags = SIGNAL_GROUP_EXIT; next = current->signal->core_state->dumper.next; current->signal->core_state = NULL; spin_unlock_irq(¤t->sighand->siglock); @@ -895,6 +892,63 @@ int dump_align(struct coredump_params *cprm, int align) } EXPORT_SYMBOL(dump_align); +#ifdef CONFIG_SYSCTL + +void validate_coredump_safety(void) +{ + if (suid_dumpable == SUID_DUMP_ROOT && + core_pattern[0] != '/' && core_pattern[0] != '|') { + pr_warn( +"Unsafe core_pattern used with fs.suid_dumpable=2.\n" +"Pipe handler or fully qualified core dump path required.\n" +"Set kernel.core_pattern before fs.suid_dumpable.\n" + ); + } +} + +static int proc_dostring_coredump(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + int error = proc_dostring(table, write, buffer, lenp, ppos); + + if (!error) + validate_coredump_safety(); + return error; +} + +static struct ctl_table coredump_sysctls[] = { + { + .procname = "core_uses_pid", + .data = &core_uses_pid, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "core_pattern", + .data = core_pattern, + .maxlen = CORENAME_MAX_SIZE, + .mode = 0644, + .proc_handler = proc_dostring_coredump, + }, + { + .procname = "core_pipe_limit", + .data = &core_pipe_limit, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { } +}; + +static int __init init_fs_coredump_sysctls(void) +{ + register_sysctl_init("kernel", coredump_sysctls); + return 0; +} +fs_initcall(init_fs_coredump_sysctls); +#endif /* CONFIG_SYSCTL */ + /* * The purpose of always_dump_vma() is to make sure that special kernel mappings * that are useful for post-mortem analysis are included in every core dump. |