Date: Thu, 16 Jul 2020 13:38:20 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r363245 - in stable/12: lib/libc/sys sys/kern Message-ID: <202007161338.06GDcKjT026474@repo.freebsd.org>
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Author: markj Date: Thu Jul 16 13:38:20 2020 New Revision: 363245 URL: https://svnweb.freebsd.org/changeset/base/363245 Log: MFC r363051, r363055: Avoid copying out kernel pointers from msgctl/semctl(IPC_STAT). Modified: stable/12/lib/libc/sys/msgctl.2 stable/12/lib/libc/sys/semctl.2 stable/12/sys/kern/sysv_msg.c stable/12/sys/kern/sysv_sem.c Directory Properties: stable/12/ (props changed) Modified: stable/12/lib/libc/sys/msgctl.2 ============================================================================== --- stable/12/lib/libc/sys/msgctl.2 Thu Jul 16 13:37:32 2020 (r363244) +++ stable/12/lib/libc/sys/msgctl.2 Thu Jul 16 13:38:20 2020 (r363245) @@ -31,7 +31,7 @@ .\" .\" $FreeBSD$ .\"/ -.Dd July 9, 2009 +.Dd July 9, 2020 .Dt MSGCTL 2 .Os .Sh NAME @@ -63,8 +63,6 @@ and contains (amongst others) the following members: .Bd -literal struct msqid_ds { struct ipc_perm msg_perm; /* msg queue permission bits */ - struct msg *__msg_first; /* kernel data, don't use */ - struct msg *__msg_last; /* kernel data, don't use */ msglen_t msg_cbytes; /* number of bytes in use on the queue */ msgqnum_t msg_qnum; /* number of msgs in the queue */ msglen_t msg_qbytes; /* max # of bytes on the queue */ Modified: stable/12/lib/libc/sys/semctl.2 ============================================================================== --- stable/12/lib/libc/sys/semctl.2 Thu Jul 16 13:37:32 2020 (r363244) +++ stable/12/lib/libc/sys/semctl.2 Thu Jul 16 13:38:20 2020 (r363245) @@ -25,7 +25,7 @@ .\" .\" $FreeBSD$ .\" -.Dd February 23, 2018 +.Dd July 9, 2020 .Dt SEMCTL 2 .Os .Sh NAME @@ -148,7 +148,6 @@ is defined as follows: .Bd -literal struct semid_ds { struct ipc_perm sem_perm; /* operation permission struct */ - struct sem *__sem_base; /* kernel data, don't use */ u_short sem_nsems; /* number of sems in set */ time_t sem_otime; /* last operation time */ time_t sem_ctime; /* last change time */ Modified: stable/12/sys/kern/sysv_msg.c ============================================================================== --- stable/12/sys/kern/sysv_msg.c Thu Jul 16 13:37:32 2020 (r363244) +++ stable/12/sys/kern/sysv_msg.c Thu Jul 16 13:38:20 2020 (r363245) @@ -615,6 +615,13 @@ kern_msgctl(struct thread *td, int msqid, int cmd, str *msqbuf = msqkptr->u; if (td->td_ucred->cr_prison != msqkptr->cred->cr_prison) msqbuf->msg_perm.key = IPC_PRIVATE; + + /* + * Try to hide the fact that the structure layout is shared by + * both the kernel and userland. These pointers are not useful + * to userspace. + */ + msqbuf->__msg_first = msqbuf->__msg_last = NULL; break; default: Modified: stable/12/sys/kern/sysv_sem.c ============================================================================== --- stable/12/sys/kern/sysv_sem.c Thu Jul 16 13:37:32 2020 (r363244) +++ stable/12/sys/kern/sysv_sem.c Thu Jul 16 13:38:20 2020 (r363245) @@ -798,6 +798,13 @@ kern_semctl(struct thread *td, int semid, int semnum, bcopy(&semakptr->u, arg->buf, sizeof(struct semid_ds)); if (cred->cr_prison != semakptr->cred->cr_prison) arg->buf->sem_perm.key = IPC_PRIVATE; + + /* + * Try to hide the fact that the structure layout is shared by + * both the kernel and userland. This pointer is not useful to + * userspace. + */ + arg->buf->__sem_base = NULL; break; case GETNCNT:
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