[PATCH v2 3/3] coredump: escape / in hostname and comm

Jiri Slaby
2011-05-12T06:18:13Z

Change every occurence of / in comm and hostname to !. If the process
changes its name to contain /, the core is not dumped (if the
directory tree doesn't exist like that). The same with hostname being
something like myhost/3. Fix this behaviour by using the escape loop
used in %E. (We extract it to a separate function.)

Now both with comm == myprocess/1 and hostname == myhost/1, the core
is dumped like (kernel.core_pattern='core.%p.%e.%h):
core.2349.myprocess!1.myhost!1

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
---
fs/exec.c | 22 +++++++++++++++-------
1 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index 8900f61..dafded4 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1547,10 +1547,17 @@ expand_fail:
return ret;
}

+static void cn_escape(char *str)
+{
+ for (; *str; str++)
+ if (*str == '/')
+ *str = '!';
+}
+
static int cn_print_exe_file(struct core_name *cn)
{
struct file *exe_file;
- char *pathbuf, *path, *p;
+ char *pathbuf, *path;
int ret;

exe_file = get_mm_exe_file(current->mm);
@@ -1572,9 +1579,7 @@ static int cn_print_exe_file(struct core_name *cn)
goto free_buf;
}

- for (p = path; *p; p++)
- if (*p == '/')
- *p = '!';
+ cn_escape(path);

ret = cn_printf(cn, "%s", path);

@@ -1652,17 +1657,20 @@ static int format_corename(struct core_name *cn, long signr)
break;
}
/* hostname */
- case 'h':
+ case 'h': {
+ char *namestart = cn->corename + cn->used;
down_read(&uts_sem);
err = cn_printf(cn, "%s",
utsname()->nodename);
up_read(&uts_sem);
+ cn_escape(namestart);
break;
+ }
/* executable */
case 'e': {
char comm[TASK_COMM_LEN];
- err = cn_printf(cn, "%s",
- get_task_comm(comm, current));
+ cn_escape(get_task_comm(comm, current));
+ err = cn_printf(cn, "%s", comm);
break;
}
case 'E':
--
1.7.4.2