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 <skinsbur...@parallels.com> --- include/uapi/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/uapi/linux/shm.h b/include/uapi/linux/shm.h index ec36fa1..d7413fd 100644 --- a/include/uapi/linux/shm.h +++ b/include/uapi/linux/shm.h @@ -56,6 +56,7 @@ 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 af30d13..35c750d 100644 --- a/ipc/compat.c +++ b/ipc/compat.c @@ -692,6 +692,7 @@ 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 80b0046..aebc50d 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -636,6 +636,9 @@ 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; } @@ -740,12 +743,13 @@ 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) ? cmd : IPC_SET, &shmid64.shm_perm, 0); if (IS_ERR(ipcp)) return PTR_ERR(ipcp); @@ -759,6 +763,10 @@ 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: err = ipc_update_perm(&shmid64.shm_perm, ipcp); if (err) @@ -938,6 +946,7 @@ 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 24ab414..62b2447 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -5027,6 +5027,7 @@ 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 38be92c..c7eabc9 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -2121,6 +2121,7 @@ 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: _______________________________________________ Devel mailing list Devel@openvz.org https://openvz.org/mailman/listinfo/devel