coredump: kill cn_escape(), introduce cn_esc_printf()
The usage of cn_escape() looks really annoying, imho this sequence needs a
wrapper. And it is buggy. If cn_printf() does expand_corename()
cn_escape() writes to the freed memory.
Introduce cn_esc_printf() which hopefully does this all right. It records
the index before cn_vprintf(), not "char *" which is no longer valid (in
general) after krealloc().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Colin Walters <walters@verbum.org>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Cc: Lucas De Marchi <lucas.de.marchi@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/coredump.c b/fs/coredump.c
index 2b1d1f5..90d7cee 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -99,11 +99,21 @@
return ret;
}
-static void cn_escape(char *str)
+static int cn_esc_printf(struct core_name *cn, const char *fmt, ...)
{
- for (; *str; str++)
- if (*str == '/')
- *str = '!';
+ int cur = cn->used;
+ va_list arg;
+ int ret;
+
+ va_start(arg, fmt);
+ ret = cn_vprintf(cn, fmt, arg);
+ va_end(arg);
+
+ for (; cur < cn->used; ++cur) {
+ if (cn->corename[cur] == '/')
+ cn->corename[cur] = '!';
+ }
+ return ret;
}
static int cn_print_exe_file(struct core_name *cn)
@@ -113,12 +123,8 @@
int ret;
exe_file = get_mm_exe_file(current->mm);
- if (!exe_file) {
- char *commstart = cn->corename + cn->used;
- ret = cn_printf(cn, "%s (path unknown)", current->comm);
- cn_escape(commstart);
- return ret;
- }
+ if (!exe_file)
+ return cn_esc_printf(cn, "%s (path unknown)", current->comm);
pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY);
if (!pathbuf) {
@@ -132,9 +138,7 @@
goto free_buf;
}
- cn_escape(path);
-
- ret = cn_printf(cn, "%s", path);
+ ret = cn_esc_printf(cn, "%s", path);
free_buf:
kfree(pathbuf);
@@ -207,22 +211,16 @@
break;
}
/* hostname */
- case 'h': {
- char *namestart = cn->corename + cn->used;
+ case 'h':
down_read(&uts_sem);
- err = cn_printf(cn, "%s",
+ err = cn_esc_printf(cn, "%s",
utsname()->nodename);
up_read(&uts_sem);
- cn_escape(namestart);
break;
- }
/* executable */
- case 'e': {
- char *commstart = cn->corename + cn->used;
- err = cn_printf(cn, "%s", current->comm);
- cn_escape(commstart);
+ case 'e':
+ err = cn_esc_printf(cn, "%s", current->comm);
break;
- }
case 'E':
err = cn_print_exe_file(cn);
break;