From cb79f1998d89821a4dbac47f59a46ee3fbbf3c61 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 26 Jan 2008 16:49:44 -0500 Subject: dlm: dlm/user.c input validation fixes a) in device_write(): add sentinel NUL byte, making sure that lspace.name will be NUL-terminated b) in compat_input() be keep it simple about the amounts of data we are copying. Signed-off-by: Al Viro Signed-off-by: David Teigland --- fs/dlm/user.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) (limited to 'fs') diff --git a/fs/dlm/user.c b/fs/dlm/user.c index 7cbc6826239b..c3060458b68e 100644 --- a/fs/dlm/user.c +++ b/fs/dlm/user.c @@ -82,7 +82,7 @@ struct dlm_lock_result32 { static void compat_input(struct dlm_write_request *kb, struct dlm_write_request32 *kb32, - int max_namelen) + size_t count) { kb->version[0] = kb32->version[0]; kb->version[1] = kb32->version[1]; @@ -94,7 +94,8 @@ static void compat_input(struct dlm_write_request *kb, kb->cmd == DLM_USER_REMOVE_LOCKSPACE) { kb->i.lspace.flags = kb32->i.lspace.flags; kb->i.lspace.minor = kb32->i.lspace.minor; - strcpy(kb->i.lspace.name, kb32->i.lspace.name); + memcpy(kb->i.lspace.name, kb32->i.lspace.name, count - + offsetof(struct dlm_write_request32, i.lspace.name)); } else if (kb->cmd == DLM_USER_PURGE) { kb->i.purge.nodeid = kb32->i.purge.nodeid; kb->i.purge.pid = kb32->i.purge.pid; @@ -112,11 +113,8 @@ static void compat_input(struct dlm_write_request *kb, kb->i.lock.bastaddr = (void *)(long)kb32->i.lock.bastaddr; kb->i.lock.lksb = (void *)(long)kb32->i.lock.lksb; memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN); - if (kb->i.lock.namelen <= max_namelen) - memcpy(kb->i.lock.name, kb32->i.lock.name, - kb->i.lock.namelen); - else - kb->i.lock.namelen = max_namelen; + memcpy(kb->i.lock.name, kb32->i.lock.name, count - + offsetof(struct dlm_write_request32, i.lock.name)); } } @@ -508,7 +506,7 @@ static ssize_t device_write(struct file *file, const char __user *buf, #endif return -EINVAL; - kbuf = kmalloc(count, GFP_KERNEL); + kbuf = kzalloc(count + 1, GFP_KERNEL); if (!kbuf) return -ENOMEM; @@ -526,15 +524,14 @@ static ssize_t device_write(struct file *file, const char __user *buf, if (!kbuf->is64bit) { struct dlm_write_request32 *k32buf; k32buf = (struct dlm_write_request32 *)kbuf; - kbuf = kmalloc(count + (sizeof(struct dlm_write_request) - + kbuf = kmalloc(count + 1 + (sizeof(struct dlm_write_request) - sizeof(struct dlm_write_request32)), GFP_KERNEL); if (!kbuf) return -ENOMEM; if (proc) set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags); - compat_input(kbuf, k32buf, - count - sizeof(struct dlm_write_request32)); + compat_input(kbuf, k32buf, count + 1); kfree(k32buf); } #endif -- cgit v1.2.1