path: root/fs/dlm/user.c
diff options
authorDavid Teigland <teigland@redhat.com>2013-02-04 15:31:22 -0600
committerDavid Teigland <teigland@redhat.com>2013-02-04 15:31:22 -0600
commitd4b0bcf32b946590afd29e202d6a399b84fe6c67 (patch)
treeab44da9a693c1e7fd22e5f45d26e1e7742281516 /fs/dlm/user.c
parent6edacf05c8362f4c368991b55d85e8122cfc9a24 (diff)
dlm: check the write size from user
Return EINVAL from write if the size is larger than allowed. Do this before allocating kernel memory for the bogus size, which could lead to OOM. Reported-by: Sasha Levin <levinsasha928@gmail.com> Tested-by: Jana Saout <jana@saout.de> Signed-off-by: David Teigland <teigland@redhat.com>
Diffstat (limited to 'fs/dlm/user.c')
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index 7ff49852b0c..911649a47dd 100644
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -503,11 +503,11 @@ static ssize_t device_write(struct file *file, const char __user *buf,
return -EINVAL;
- if (count > sizeof(struct dlm_write_request32) + DLM_RESNAME_MAXLEN)
+ /*
+ * can't compare against COMPAT/dlm_write_request32 because
+ * we don't yet know if is64bit is zero
+ */
if (count > sizeof(struct dlm_write_request) + DLM_RESNAME_MAXLEN)
return -EINVAL;
kbuf = kzalloc(count + 1, GFP_NOFS);