Date: Mon, 12 Feb 2018 18:40:19 +0000 (UTC) From: Brooks Davis <brooks@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r329177 - in stable/11/sys: compat/freebsd32 kern Message-ID: <201802121840.w1CIeJ4l099785@repo.freebsd.org>
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Author: brooks Date: Mon Feb 12 18:40:19 2018 New Revision: 329177 URL: https://svnweb.freebsd.org/changeset/base/329177 Log: MFC r328799: Add kern.ipc.{msqids,semsegs,sema} sysctls for FreeBSD32. Stop leaking kernel pointers though theses sysctls and make sure that the padding in the structures is zeroed on allocation to avoid other leaks. Reviewed by: gordon, kib Obtained from: CheriBSD Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D13459 Modified: stable/11/sys/compat/freebsd32/freebsd32_ipc.h stable/11/sys/kern/sysv_msg.c stable/11/sys/kern/sysv_sem.c stable/11/sys/kern/sysv_shm.c Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/compat/freebsd32/freebsd32_ipc.h ============================================================================== --- stable/11/sys/compat/freebsd32/freebsd32_ipc.h Mon Feb 12 18:30:20 2018 (r329176) +++ stable/11/sys/compat/freebsd32/freebsd32_ipc.h Mon Feb 12 18:40:19 2018 (r329177) @@ -47,6 +47,18 @@ struct semid_ds32 { int32_t sem_ctime; }; +#ifdef _KERNEL +struct semid_kernel32 { + /* Data structure exposed to user space. */ + struct semid_ds32 u; + + /* Kernel-private components of the semaphore. */ + int32_t label; + int32_t cred; +}; +#endif /* _KERNEL */ + + union semun32 { int val; uint32_t buf; @@ -67,6 +79,17 @@ struct msqid_ds32 { int32_t msg_ctime; }; +#ifdef _KERNEL +struct msqid_kernel32 { + /* Data structure exposed to user space. */ + struct msqid_ds32 u; + + /* Kernel-private components of the message queue. */ + uint32_t label; + uint32_t cred; +}; +#endif + struct shmid_ds32 { struct ipc_perm32 shm_perm; int32_t shm_segsz; @@ -77,6 +100,15 @@ struct shmid_ds32 { int32_t shm_dtime; int32_t shm_ctime; }; + +#ifdef _KERNEL +struct shmid_kernel32 { + struct shmid_ds32 u; + int32_t *object; + int32_t *label; + int32_t *cred; +}; +#endif struct shm_info32 { int32_t used_ids; Modified: stable/11/sys/kern/sysv_msg.c ============================================================================== --- stable/11/sys/kern/sysv_msg.c Mon Feb 12 18:30:20 2018 (r329176) +++ stable/11/sys/kern/sysv_msg.c Mon Feb 12 18:40:19 2018 (r329177) @@ -220,7 +220,7 @@ msginit() msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK); msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK); msqids = malloc(sizeof(struct msqid_kernel) * msginfo.msgmni, M_MSG, - M_WAITOK); + M_WAITOK | M_ZERO); /* * msginfo.msgssz should be a power of two for efficiency reasons. @@ -1417,7 +1417,12 @@ static int sysctl_msqids(SYSCTL_HANDLER_ARGS) { struct msqid_kernel tmsqk; +#ifdef COMPAT_FREEBSD32 + struct msqid_kernel32 tmsqk32; +#endif struct prison *pr, *rpr; + void *outaddr; + size_t outsize; int error, i; pr = req->td->td_ucred->cr_prison; @@ -1434,7 +1439,40 @@ sysctl_msqids(SYSCTL_HANDLER_ARGS) tmsqk.u.msg_perm.key = IPC_PRIVATE; } mtx_unlock(&msq_mtx); - error = SYSCTL_OUT(req, &tmsqk, sizeof(tmsqk)); +#ifdef COMPAT_FREEBSD32 + if (SV_CURPROC_FLAG(SV_ILP32)) { + bzero(&tmsqk32, sizeof(tmsqk32)); + freebsd32_ipcperm_out(&tmsqk.u.msg_perm, + &tmsqk32.u.msg_perm); + /* Don't copy u.msg_first or u.msg_last */ + CP(tmsqk, tmsqk32, u.msg_cbytes); + CP(tmsqk, tmsqk32, u.msg_qnum); + CP(tmsqk, tmsqk32, u.msg_qbytes); + CP(tmsqk, tmsqk32, u.msg_lspid); + CP(tmsqk, tmsqk32, u.msg_lrpid); + CP(tmsqk, tmsqk32, u.msg_stime); + CP(tmsqk, tmsqk32, u.msg_rtime); + CP(tmsqk, tmsqk32, u.msg_ctime); + /* Don't copy label or cred */ + outaddr = &tmsqk32; + outsize = sizeof(tmsqk32); + } else +#endif + { + /* Don't leak kernel pointers */ + tmsqk.u.msg_first = NULL; + tmsqk.u.msg_last = NULL; + tmsqk.label = NULL; + tmsqk.cred = NULL; + /* + * XXX: some padding also exists, but we take care to + * allocate our pool of msqid_kernel structs with + * zeroed memory so this should be OK. + */ + outaddr = &tmsqk; + outsize = sizeof(tmsqk); + } + error = SYSCTL_OUT(req, outaddr, outsize); if (error != 0) break; } Modified: stable/11/sys/kern/sysv_sem.c ============================================================================== --- stable/11/sys/kern/sysv_sem.c Mon Feb 12 18:30:20 2018 (r329176) +++ stable/11/sys/kern/sysv_sem.c Mon Feb 12 18:40:19 2018 (r329177) @@ -271,7 +271,7 @@ seminit(void) sem = malloc(sizeof(struct sem) * seminfo.semmns, M_SEM, M_WAITOK); sema = malloc(sizeof(struct semid_kernel) * seminfo.semmni, M_SEM, - M_WAITOK); + M_WAITOK | M_ZERO); sema_mtx = malloc(sizeof(struct mtx) * seminfo.semmni, M_SEM, M_WAITOK | M_ZERO); semu = malloc(seminfo.semmnu * seminfo.semusz, M_SEM, M_WAITOK); @@ -1467,6 +1467,11 @@ sysctl_sema(SYSCTL_HANDLER_ARGS) { struct prison *pr, *rpr; struct semid_kernel tsemak; +#ifdef COMPAT_FREEBSD32 + struct semid_kernel32 tsemak32; +#endif + void *outaddr; + size_t outsize; int error, i; pr = req->td->td_ucred->cr_prison; @@ -1483,7 +1488,28 @@ sysctl_sema(SYSCTL_HANDLER_ARGS) tsemak.u.sem_perm.key = IPC_PRIVATE; } mtx_unlock(&sema_mtx[i]); - error = SYSCTL_OUT(req, &tsemak, sizeof(tsemak)); +#ifdef COMPAT_FREEBSD32 + if (SV_CURPROC_FLAG(SV_ILP32)) { + bzero(&tsemak32, sizeof(tsemak32)); + freebsd32_ipcperm_out(&tsemak.u.sem_perm, + &tsemak32.u.sem_perm); + /* Don't copy u.sem_base */ + CP(tsemak, tsemak32, u.sem_nsems); + CP(tsemak, tsemak32, u.sem_otime); + CP(tsemak, tsemak32, u.sem_ctime); + /* Don't copy label or cred */ + outaddr = &tsemak32; + outsize = sizeof(tsemak32); + } else +#endif + { + tsemak.u.sem_base = NULL; + tsemak.label = NULL; + tsemak.cred = NULL; + outaddr = &tsemak; + outsize = sizeof(tsemak); + } + error = SYSCTL_OUT(req, outaddr, outsize); if (error != 0) break; } Modified: stable/11/sys/kern/sysv_shm.c ============================================================================== --- stable/11/sys/kern/sysv_shm.c Mon Feb 12 18:30:20 2018 (r329176) +++ stable/11/sys/kern/sysv_shm.c Mon Feb 12 18:40:19 2018 (r329177) @@ -844,7 +844,8 @@ shmrealloc(void) if (shmalloced >= shminfo.shmmni) return; - newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK); + newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, + M_WAITOK | M_ZERO); for (i = 0; i < shmalloced; i++) bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0])); for (; i < shminfo.shmmni; i++) { @@ -922,7 +923,8 @@ shminit(void) } } shmalloced = shminfo.shmmni; - shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK); + shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, + M_WAITOK|M_ZERO); for (i = 0; i < shmalloced; i++) { shmsegs[i].u.shm_perm.mode = SHMSEG_FREE; shmsegs[i].u.shm_perm.seq = 0; @@ -1009,7 +1011,12 @@ static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS) { struct shmid_kernel tshmseg; +#ifdef COMPAT_FREEBSD32 + struct shmid_kernel32 tshmseg32; +#endif struct prison *pr, *rpr; + void *outaddr; + size_t outsize; int error, i; SYSVSHM_LOCK(); @@ -1026,7 +1033,31 @@ sysctl_shmsegs(SYSCTL_HANDLER_ARGS) if (tshmseg.cred->cr_prison != pr) tshmseg.u.shm_perm.key = IPC_PRIVATE; } - error = SYSCTL_OUT(req, &tshmseg, sizeof(tshmseg)); +#ifdef COMPAT_FREEBSD32 + if (SV_CURPROC_FLAG(SV_ILP32)) { + bzero(&tshmseg32, sizeof(tshmseg32)); + freebsd32_ipcperm_out(&tshmseg.u.shm_perm, + &tshmseg32.u.shm_perm); + CP(tshmseg, tshmseg32, u.shm_segsz); + CP(tshmseg, tshmseg32, u.shm_lpid); + CP(tshmseg, tshmseg32, u.shm_cpid); + CP(tshmseg, tshmseg32, u.shm_nattch); + CP(tshmseg, tshmseg32, u.shm_atime); + CP(tshmseg, tshmseg32, u.shm_dtime); + CP(tshmseg, tshmseg32, u.shm_ctime); + /* Don't copy object, label, or cred */ + outaddr = &tshmseg32; + outsize = sizeof(tshmseg32); + } else +#endif + { + tshmseg.object = NULL; + tshmseg.label = NULL; + tshmseg.cred = NULL; + outaddr = &tshmseg; + outsize = sizeof(tshmseg); + } + error = SYSCTL_OUT(req, outaddr, outsize); if (error != 0) break; }
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