diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2013-09-11 14:24:38 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-09-11 15:59:03 -0700 |
| commit | 5d1baf3b63bfc8c709dc44df85ff1475c7ef489d (patch) | |
| tree | c22cad96687d70a544674f7eb823026aecf4ceeb | |
| parent | 96d0df79f2644fc823f26c06491e182d87a90c2a (diff) | |
| download | linux-5d1baf3b63bfc8c709dc44df85ff1475c7ef489d.tar.bz2 | |
exec: introduce exec_binprm() for "depth == 0" code
task_pid_nr_ns() and trace/ptrace code in the middle of the recursive
search_binary_handler() looks confusing and imho annoying. We only need
this code if "depth == 0", lets add a simple helper which calls
search_binary_handler() and does trace_sched_process_exec() +
ptrace_event().
The patch also moves the setting of task->did_exec, we need to do this
only once.
Note: we can kill either task->did_exec or PF_FORKNOEXEC.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Zach Levis <zml@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/exec.c | 36 |
1 files changed, 22 insertions, 14 deletions
diff --git a/fs/exec.c b/fs/exec.c index 2d1e52a58fe9..4d95b4709ea0 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1373,7 +1373,6 @@ int search_binary_handler(struct linux_binprm *bprm) unsigned int depth = bprm->recursion_depth; int try,retval; struct linux_binfmt *fmt; - pid_t old_pid, old_vpid; /* This allows 4 levels of binfmt rewrites before failing hard. */ if (depth > 5) @@ -1387,12 +1386,6 @@ int search_binary_handler(struct linux_binprm *bprm) if (retval) return retval; - /* Need to fetch pid before load_binary changes it */ - old_pid = current->pid; - rcu_read_lock(); - old_vpid = task_pid_nr_ns(current, task_active_pid_ns(current->parent)); - rcu_read_unlock(); - retval = -ENOENT; for (try=0; try<2; try++) { read_lock(&binfmt_lock); @@ -1407,16 +1400,11 @@ int search_binary_handler(struct linux_binprm *bprm) retval = fn(bprm); bprm->recursion_depth = depth; if (retval >= 0) { - if (depth == 0) { - trace_sched_process_exec(current, old_pid, bprm); - ptrace_event(PTRACE_EVENT_EXEC, old_vpid); - } put_binfmt(fmt); allow_write_access(bprm->file); if (bprm->file) fput(bprm->file); bprm->file = NULL; - current->did_exec = 1; proc_exec_connector(current); return retval; } @@ -1450,9 +1438,29 @@ int search_binary_handler(struct linux_binprm *bprm) } return retval; } - EXPORT_SYMBOL(search_binary_handler); +static int exec_binprm(struct linux_binprm *bprm) +{ + pid_t old_pid, old_vpid; + int ret; + + /* Need to fetch pid before load_binary changes it */ + old_pid = current->pid; + rcu_read_lock(); + old_vpid = task_pid_nr_ns(current, task_active_pid_ns(current->parent)); + rcu_read_unlock(); + + ret = search_binary_handler(bprm); + if (ret >= 0) { + trace_sched_process_exec(current, old_pid, bprm); + ptrace_event(PTRACE_EVENT_EXEC, old_vpid); + current->did_exec = 1; + } + + return ret; +} + /* * sys_execve() executes a new program. */ @@ -1541,7 +1549,7 @@ static int do_execve_common(const char *filename, if (retval < 0) goto out; - retval = search_binary_handler(bprm); + retval = exec_binprm(bprm); if (retval < 0) goto out; |