coredump: format_corename() can leak cn->corename
do_coredump() assumes that format_corename() can only fail if
expand_corename() fails and frees cn->corename. This is not true, for
example cn_print_exe_file() can fail and in this case nobody frees
cn->corename.
Change do_coredump() to always do kfree(cn->corename) after it calls
format_corename() (NULL is fine), change expand_corename() to do nothing
if kmalloc() fails.
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 dafafba..11bc368 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -58,16 +58,14 @@
static int expand_corename(struct core_name *cn)
{
- char *old_corename = cn->corename;
+ int size = CORENAME_MAX_SIZE * atomic_inc_return(&call_count);
+ char *corename = krealloc(cn->corename, size, GFP_KERNEL);
- cn->size = CORENAME_MAX_SIZE * atomic_inc_return(&call_count);
- cn->corename = krealloc(old_corename, cn->size, GFP_KERNEL);
-
- if (!cn->corename) {
- kfree(old_corename);
+ if (!corename)
return -ENOMEM;
- }
+ cn->size = size;
+ cn->corename = corename;
return 0;
}
@@ -157,10 +155,9 @@
int pid_in_pattern = 0;
int err = 0;
+ cn->used = 0;
cn->size = CORENAME_MAX_SIZE * atomic_read(&call_count);
cn->corename = kmalloc(cn->size, GFP_KERNEL);
- cn->used = 0;
-
if (!cn->corename)
return -ENOMEM;
@@ -549,7 +546,7 @@
if (ispipe < 0) {
printk(KERN_WARNING "format_corename failed\n");
printk(KERN_WARNING "Aborting core\n");
- goto fail_corename;
+ goto fail_unlock;
}
if (cprm.limit == 1) {
@@ -669,7 +666,6 @@
atomic_dec(&core_dump_count);
fail_unlock:
kfree(cn.corename);
-fail_corename:
coredump_finish(mm, core_dumped);
revert_creds(old_cred);
fail_creds: