Messages in this thread Patch in this message | | | Subject | [PATCH v4 4/9] ipc: add new SHM_SET command for sys_shmctl() call | From | Stanislav Kinsbursky <> | Date | Mon, 13 Aug 2012 16:31:54 +0400 |
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New SHM_SET command will be interpreted exactly as IPC_SET, but also will update key, cuid and cgid values. IOW, it allows to change existent key value. The fact, that key is not used is checked before update. Otherwise -EEXIST is returned.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> --- include/linux/shm.h | 1 + ipc/compat.c | 1 + ipc/shm.c | 13 +++++++++++-- security/selinux/hooks.c | 1 + security/smack/smack_lsm.c | 1 + 5 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/include/linux/shm.h b/include/linux/shm.h index 92808b8..6fc5447 100644 --- a/include/linux/shm.h +++ b/include/linux/shm.h @@ -63,6 +63,7 @@ struct shmid_ds { /* ipcs ctl commands */ #define SHM_STAT 13 #define SHM_INFO 14 +#define SHM_SET 15 /* Obsolete, used only for backwards compatibility */ struct shminfo { diff --git a/ipc/compat.c b/ipc/compat.c index aa88515..e7d4af7 100644 --- a/ipc/compat.c +++ b/ipc/compat.c @@ -688,6 +688,7 @@ long compat_sys_shmctl(int first, int second, void __user *uptr) case IPC_SET: + case SHM_SET: if (version == IPC_64) { err = get_compat_shmid64_ds(&s64, uptr); } else { diff --git a/ipc/shm.c b/ipc/shm.c index d4c0a9e..677b9f6 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -635,6 +635,9 @@ copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version) out->shm_perm.uid = tbuf_old.shm_perm.uid; out->shm_perm.gid = tbuf_old.shm_perm.gid; out->shm_perm.mode = tbuf_old.shm_perm.mode; + out->shm_perm.cuid = tbuf_old.shm_perm.cuid; + out->shm_perm.cgid = tbuf_old.shm_perm.cgid; + out->shm_perm.key = tbuf_old.shm_perm.key; return 0; } @@ -739,12 +742,13 @@ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, struct shmid_kernel *shp; int err; - if (cmd == IPC_SET) { + if (cmd == IPC_SET || cmd == SHM_SET) { if (copy_shmid_from_user(&shmid64, buf, version)) return -EFAULT; } - ipcp = ipcctl_pre_down(ns, &shm_ids(ns), shmid, cmd, + ipcp = ipcctl_pre_down(ns, &shm_ids(ns), shmid, + (cmd != SHM_SET) ? : IPC_SET, &shmid64.shm_perm, 0); if (IS_ERR(ipcp)) return PTR_ERR(ipcp); @@ -758,6 +762,10 @@ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, case IPC_RMID: do_shm_rmid(ns, ipcp); goto out_up; + case SHM_SET: + err = ipc_update_key(&shm_ids(ns), &shmid64.shm_perm, ipcp); + if (err) + break; case IPC_SET: ipc_update_perm(&shmid64.shm_perm, ipcp); shp->shm_ctim = get_seconds(); @@ -935,6 +943,7 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) } case IPC_RMID: case IPC_SET: + case SHM_SET: err = shmctl_down(ns, shmid, cmd, buf, version); return err; default: diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 6c56ebf..9e07e22 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -5054,6 +5054,7 @@ static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd) perms = SHM__GETATTR | SHM__ASSOCIATE; break; case IPC_SET: + case SHM_SET: perms = SHM__SETATTR; break; case SHM_LOCK: diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index ee0bb57..a25dfd1 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -2145,6 +2145,7 @@ static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd) may = MAY_READ; break; case IPC_SET: + case SHM_SET: case SHM_LOCK: case SHM_UNLOCK: case IPC_RMID:
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