when mounting with modefromsid, we end up writing 4 ACE in a security descriptor that only has room for 3, thus triggering an out-of-bounds write. fix this by changing the min size of a security descriptor. Signed-off-by: Aurelien Aptel <aaptel@xxxxxxxx> --- fs/cifs/cifsacl.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/cifs/cifsacl.h b/fs/cifs/cifsacl.h index dd95a6fa24bf..eb428349f29a 100644 --- a/fs/cifs/cifsacl.h +++ b/fs/cifs/cifsacl.h @@ -45,7 +45,7 @@ */ #define DEFAULT_SEC_DESC_LEN (sizeof(struct cifs_ntsd) + \ sizeof(struct cifs_acl) + \ - (sizeof(struct cifs_ace) * 3)) + (sizeof(struct cifs_ace) * 4)) /* * Maximum size of a string representation of a SID: -- 2.16.4
