d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Make sure we restrict Linux only IPC calls from being executed

Browse Source 
through the FreeBSD ABI.  IPC_INFO, SHM_INFO, SHM_STAT were added
specifically for Linux binary support.  They are not documented
as being a part of the FreeBSD ABI, also, the structures necessary
for them have been hidden away from the users for a long time.

Also, the Linux ABI layer uses it's own structures to populate the
responses back to the user to ensure that the ABI is consistent.

I think there is a bit more separation work that needs to happen.

Reviewed by:	jhb
Discussed with:	jhb
Discussed on:	freebsd-arch@ (very briefly)
MFC after:	1 month
This commit is contained in:
Christian S.J. Peron 2008-02-12 20:55:03 +00:00
parent b95bd24d29
commit 4f18813f1f
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=176221
3 changed files with 22 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
sys/kern/sysv_shm.c
View File

@ -545,6 +545,15 @@ kern_shmctl(td, shmid, cmd, buf, bufsz)
mtx_lock(&Giant);
switch (cmd) {
/*
* It is possible that kern_shmctl is being called from the Linux ABI
* layer, in which case, we will need to implement IPC_INFO. It should
* be noted that other shmctl calls will be funneled through here for
* Linix binaries as well.
*
* NB: The Linux ABI layer will convert this data to structure(s) more
* consistent with the Linux ABI.
*/
case IPC_INFO:
memcpy(buf, &shminfo, sizeof(shminfo));
if (bufsz)
@ -639,6 +648,15 @@ shmctl(td, uap)
struct shmid_ds buf;
size_t bufsz;
/*
* The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
* Linux binaries. If we see the call come through the FreeBSD ABI,
* return an error back to the user since we do not to support this.
*/
if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
uap->cmd == SHM_STAT)
return (EINVAL);
/* IPC_SET needs to copyin the buffer before calling kern_shmctl */
if (uap->cmd == IPC_SET) {
if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds))))
@ -651,9 +669,6 @@ shmctl(td, uap)
/* Cases in which we need to copyout */
switch (uap->cmd) {
case IPC_INFO:
case SHM_INFO:
case SHM_STAT:
case IPC_STAT:
error = copyout(&buf, uap->buf, bufsz);
break;

3
sys/sys/ipc.h
View File

@ -100,6 +100,9 @@ struct ipc_perm {
#define IPC_SET 1 /* set options */
#define IPC_STAT 2 /* get options */
#if __BSD_VISIBLE
/*
* For Linux compatability.
*/
#define IPC_INFO 3 /* get info */
#endif

2
sys/sys/shm.h
View File

@ -56,7 +56,7 @@
#define SHM_LOCK 11
#define SHM_UNLOCK 12
/* ipcs shmctl commands */
/* ipcs shmctl commands for Linux compatability */
#define SHM_STAT 13
#define SHM_INFO 14