From nobody Tue Feb 21 21:03:17 2023 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4PLsFd2VmZz3tDGq; Tue, 21 Feb 2023 21:03:17 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4PLsFd2F74z4Cjq; Tue, 21 Feb 2023 21:03:17 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1677013397; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=2YkEpQkryhbpmNTptwi42PT0X/pNawD6BIHX9ubEtDY=; b=TCvyO73VeFuV9PBGSb7AS1M0kKNdSG5EVC2CrVfgGljDLknTx7Ej9ANIRSKR+kIk54ddSM InuF+vyhNKgnGj9wSgXKuwzQSBUwMiXf2Lmn5aRQuZUvJk17FdOVa9qcLaaF6MSeTv0uW2 zC0zlQ5HbnP3Ie7Yx6hKMEBINIM/drWSxmPwLZ1NOgwWY4kPlFPefr51kg2VaVAulvwAR3 qA7Mnl9roszH7xG3Ob10QRWIfiAY1OnEOV+yQdaulAkO4lHLiLWIpUZTWAA5WmDanfSV0u 1dbWENiGiV/GfQPYbLf9tPJMnNbLAAy3MCo0PtW9j5QoFqJRz/rNAABJCxsylg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1677013397; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=2YkEpQkryhbpmNTptwi42PT0X/pNawD6BIHX9ubEtDY=; b=msskdtpZZJmJa1EGEUv7rpemFAKGsfnHfhd3aGMqv5svBCUxdaswvEbaRbmjTqza6+CilV UbS8olBSv4/qOhsv6qDzlBqgef0C1+yHJoGCZZ3fjL9zKyTr46wjEIbGYCJG1PrxUFZIdv y6n85DB6MgtHvLj/uYv9NexBZwOtU3TPyVxePoF8Flb3ZZA29+U2pxyLSELPWr2xUAZYKH SfLUQoF5l/oOpN4aurfn8hMG6MD/dZ/2TGXLLe0krX5xtTbMzd+X2MVZGTqDtnk8yDdjdX DC6T1NT3oGVe86GY7ZilWx5fqD0cDU+zPa9r1h3qpsOBgkNXDC0v0lr2sVE9bg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1677013397; a=rsa-sha256; cv=none; b=tezJKchK31+/ga2bStpdwIYFgMef6kS9BwsBSL1X3K9L7EMxdqdcj1JAu0YKEtYd1UqnZu myhxEqgvhRg1wxcF6WkKxPbbtK6oUPX1mWXnhePcpZP8h+KgtWZXrjQ5OPOJ6aW9ANh4pQ jZFrWKOxzVcnoy/gh5TPEU2LATK4VK0fXRvherrOxLKI3SJYZbyzqcoIaIak2lb/QrOd9G OqIiBCQf5jsSfSQ7vjFUPxMqQbULTxH0XryOp4t5HKdkqsBbW7Q+yrqkHfC3LOQ9Lf6/dg QJDR6tb57kHlwrPv7W70wDyh8laCKbTAtDu9TKTaJFfpCpGi2QJ9riDUqaCXNQ== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4PLsFd1J6YzbJ2; Tue, 21 Feb 2023 21:03:17 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 31LL3HSi024965; Tue, 21 Feb 2023 21:03:17 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 31LL3HUG024964; Tue, 21 Feb 2023 21:03:17 GMT (envelope-from git) Date: Tue, 21 Feb 2023 21:03:17 GMT Message-Id: <202302212103.31LL3HUG024964@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Rick Macklem Subject: git: 88175af8b75e - main - vfs_export: Add mnt_exjail to control exports done in prisons List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-all@freebsd.org X-BeenThere: dev-commits-src-all@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: rmacklem X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 88175af8b75ea8850757cc9dca68b6d336b82675 Auto-Submitted: auto-generated X-ThisMailContainsUnwantedMimeParts: N The branch main has been updated by rmacklem: URL: https://cgit.FreeBSD.org/src/commit/?id=88175af8b75ea8850757cc9dca68b6d336b82675 commit 88175af8b75ea8850757cc9dca68b6d336b82675 Author: Rick Macklem AuthorDate: 2023-02-21 21:00:42 +0000 Commit: Rick Macklem CommitDate: 2023-02-21 21:00:42 +0000 vfs_export: Add mnt_exjail to control exports done in prisons If there are multiple instances of mountd(8) (in different prisons), there will be confusion if they manipulate the exports of the same file system. This patch adds mnt_exjail to "struct mount" so that the credentials (and, therefore, the prison) that did the exports for that file system can be recorded. If another prison has already exported the file system, vfs_export() will fail with an error. If mnt_exjail == NULL, the file system has not been exported. mnt_exjail is checked by the NFS server, so that exports done from within a different prison will not be used. The patch also implements vfs_exjail_destroy(), which is called from prison_cleanup() to release all the mnt_exjail credential references, so that the prison can be removed. Mainly to avoid doing a scan of the mountlist for the case where there were no exports done from within the prison, a count of how many file systems have been exported from within the prison is kept in pr_exportcnt. Reviewed by: markj Discussed with: jamie Differential Revision: https://reviews.freebsd.org/D38371 MFC after: 3 months --- sys/fs/nfsserver/nfs_nfsdport.c | 24 ++++-- sys/kern/kern_jail.c | 1 + sys/kern/vfs_export.c | 164 +++++++++++++++++++++++++++++++++++++++- sys/kern/vfs_mount.c | 9 ++- sys/sys/jail.h | 3 +- sys/sys/mount.h | 7 +- 6 files changed, 194 insertions(+), 14 deletions(-) diff --git a/sys/fs/nfsserver/nfs_nfsdport.c b/sys/fs/nfsserver/nfs_nfsdport.c index cee5f96d7199..34b2f114bd7a 100644 --- a/sys/fs/nfsserver/nfs_nfsdport.c +++ b/sys/fs/nfsserver/nfs_nfsdport.c @@ -3259,8 +3259,16 @@ nfsvno_checkexp(struct mount *mp, struct sockaddr *nam, struct nfsexstuff *exp, { int error; - error = VFS_CHECKEXP(mp, nam, &exp->nes_exflag, credp, - &exp->nes_numsecflavor, exp->nes_secflavors); + error = 0; + *credp = NULL; + MNT_ILOCK(mp); + if (mp->mnt_exjail == NULL || + mp->mnt_exjail->cr_prison != curthread->td_ucred->cr_prison) + error = EACCES; + MNT_IUNLOCK(mp); + if (error == 0) + error = VFS_CHECKEXP(mp, nam, &exp->nes_exflag, credp, + &exp->nes_numsecflavor, exp->nes_secflavors); if (error) { if (NFSD_VNET(nfs_rootfhset)) { exp->nes_exflag = 0; @@ -3294,8 +3302,14 @@ nfsvno_fhtovp(struct mount *mp, fhandle_t *fhp, struct sockaddr *nam, /* Make sure the server replies ESTALE to the client. */ error = ESTALE; if (nam && !error) { - error = VFS_CHECKEXP(mp, nam, &exp->nes_exflag, credp, - &exp->nes_numsecflavor, exp->nes_secflavors); + MNT_ILOCK(mp); + if (mp->mnt_exjail == NULL || + mp->mnt_exjail->cr_prison != curthread->td_ucred->cr_prison) + error = EACCES; + MNT_IUNLOCK(mp); + if (error == 0) + error = VFS_CHECKEXP(mp, nam, &exp->nes_exflag, credp, + &exp->nes_numsecflavor, exp->nes_secflavors); if (error) { if (NFSD_VNET(nfs_rootfhset)) { exp->nes_exflag = 0; @@ -3465,7 +3479,7 @@ nfsrv_v4rootexport(void *argp, struct ucred *cred, struct thread *p) struct nameidata nd; fhandle_t fh; - error = vfs_export(NFSD_VNET(nfsv4root_mnt), &nfsexargp->export); + error = vfs_export(NFSD_VNET(nfsv4root_mnt), &nfsexargp->export, false); if ((nfsexargp->export.ex_flags & MNT_DELEXPORT) != 0) NFSD_VNET(nfs_rootfhset) = 0; else if (error == 0) { diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c index 92e8e4f34b42..b89c576b76ca 100644 --- a/sys/kern/kern_jail.c +++ b/sys/kern/kern_jail.c @@ -3332,6 +3332,7 @@ prison_cleanup(struct prison *pr) { sx_assert(&allprison_lock, SA_XLOCKED); mtx_assert(&pr->pr_mtx, MA_NOTOWNED); + vfs_exjail_delete(pr); shm_remove_prison(pr); (void)osd_jail_call(pr, PR_METHOD_REMOVE, NULL); } diff --git a/sys/kern/vfs_export.c b/sys/kern/vfs_export.c index cab37ce205ad..16d2e88bdc41 100644 --- a/sys/kern/vfs_export.c +++ b/sys/kern/vfs_export.c @@ -52,6 +52,7 @@ __FBSDID("$FreeBSD$"); #include #include #include +#include #include #include #include @@ -296,12 +297,18 @@ vfs_free_addrlist(struct netexport *nep) * and the passed in netexport. * Struct export_args *argp is the variable used to twiddle options, * the structure is described in sys/mount.h + * The do_exjail argument should be true if *mp is in the mountlist + * and false if not. It is not in the mountlist for the NFSv4 rootfs + * fake mount point just used for exports. */ int -vfs_export(struct mount *mp, struct export_args *argp) +vfs_export(struct mount *mp, struct export_args *argp, bool do_exjail) { struct netexport *nep; + struct ucred *cr; + struct prison *pr; int error; + bool new_nep; if ((argp->ex_flags & (MNT_DELEXPORT | MNT_EXPORTED)) == 0) return (EINVAL); @@ -312,6 +319,7 @@ vfs_export(struct mount *mp, struct export_args *argp) return (EINVAL); error = 0; + pr = curthread->td_ucred->cr_prison; lockmgr(&mp->mnt_explock, LK_EXCLUSIVE, NULL); nep = mp->mnt_export; if (argp->ex_flags & MNT_DELEXPORT) { @@ -319,6 +327,21 @@ vfs_export(struct mount *mp, struct export_args *argp) error = ENOENT; goto out; } + MNT_ILOCK(mp); + if (mp->mnt_exjail != NULL && mp->mnt_exjail->cr_prison != pr && + pr == &prison0) { + MNT_IUNLOCK(mp); + /* EXDEV will not get logged by mountd(8). */ + error = EXDEV; + goto out; + } else if (mp->mnt_exjail != NULL && + mp->mnt_exjail->cr_prison != pr) { + MNT_IUNLOCK(mp); + /* EPERM will get logged by mountd(8). */ + error = EPERM; + goto out; + } + MNT_IUNLOCK(mp); if (mp->mnt_flag & MNT_EXPUBLIC) { vfs_setpublicfs(NULL, NULL, NULL); MNT_ILOCK(mp); @@ -330,18 +353,51 @@ vfs_export(struct mount *mp, struct export_args *argp) free(nep, M_MOUNT); nep = NULL; MNT_ILOCK(mp); + cr = mp->mnt_exjail; + mp->mnt_exjail = NULL; mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED); MNT_IUNLOCK(mp); + if (cr != NULL) { + atomic_subtract_int(&pr->pr_exportcnt, 1); + crfree(cr); + } } if (argp->ex_flags & MNT_EXPORTED) { + new_nep = false; + MNT_ILOCK(mp); + if (mp->mnt_exjail == NULL) { + MNT_IUNLOCK(mp); + if (do_exjail && nep != NULL) { + vfs_free_addrlist(nep); + memset(nep, 0, sizeof(*nep)); + new_nep = true; + } + } else if (mp->mnt_exjail->cr_prison != pr) { + MNT_IUNLOCK(mp); + error = EPERM; + goto out; + } else + MNT_IUNLOCK(mp); if (nep == NULL) { - nep = malloc(sizeof(struct netexport), M_MOUNT, M_WAITOK | M_ZERO); + nep = malloc(sizeof(struct netexport), M_MOUNT, + M_WAITOK | M_ZERO); mp->mnt_export = nep; + new_nep = true; } if (argp->ex_flags & MNT_EXPUBLIC) { - if ((error = vfs_setpublicfs(mp, nep, argp)) != 0) + if ((error = vfs_setpublicfs(mp, nep, argp)) != 0) { + if (new_nep) { + mp->mnt_export = NULL; + free(nep, M_MOUNT); + } goto out; + } + new_nep = false; MNT_ILOCK(mp); + if (do_exjail && mp->mnt_exjail == NULL) { + mp->mnt_exjail = crhold(curthread->td_ucred); + atomic_add_int(&pr->pr_exportcnt, 1); + } mp->mnt_flag |= MNT_EXPUBLIC; MNT_IUNLOCK(mp); } @@ -349,9 +405,18 @@ vfs_export(struct mount *mp, struct export_args *argp) argp->ex_numsecflavors = 1; argp->ex_secflavors[0] = AUTH_SYS; } - if ((error = vfs_hang_addrlist(mp, nep, argp))) + if ((error = vfs_hang_addrlist(mp, nep, argp))) { + if (new_nep) { + mp->mnt_export = NULL; + free(nep, M_MOUNT); + } goto out; + } MNT_ILOCK(mp); + if (do_exjail && mp->mnt_exjail == NULL) { + mp->mnt_exjail = crhold(curthread->td_ucred); + atomic_add_int(&pr->pr_exportcnt, 1); + } mp->mnt_flag |= MNT_EXPORTED; MNT_IUNLOCK(mp); } @@ -371,6 +436,97 @@ out: return (error); } +/* + * Get rid of credential references for this prison. + */ +void +vfs_exjail_delete(struct prison *pr) +{ + struct mount *mp; + struct ucred *cr; + int error, i; + + /* + * Since this function is called from prison_cleanup() after + * all processes in the prison have exited, the value of + * pr_exportcnt can no longer increase. It is possible for + * a dismount of a file system exported within this prison + * to be in progress. In this case, the file system is no + * longer in the mountlist and the mnt_exjail will be free'd + * by vfs_mount_destroy() at some time. As such, pr_exportcnt + * and, therefore "i", is the upper bound on the number of + * mnt_exjail entries to be found by this function. + */ + i = atomic_load_int(&pr->pr_exportcnt); + KASSERT(i >= 0, ("vfs_exjail_delete: pr_exportcnt negative")); + if (i == 0) + return; + mtx_lock(&mountlist_mtx); +tryagain: + TAILQ_FOREACH(mp, &mountlist, mnt_list) { + MNT_ILOCK(mp); + if (mp->mnt_exjail != NULL && + mp->mnt_exjail->cr_prison == pr) { + MNT_IUNLOCK(mp); + error = vfs_busy(mp, MBF_MNTLSTLOCK | MBF_NOWAIT); + if (error != 0) { + /* + * If the vfs_busy() fails, we still want to + * get rid of mnt_exjail for two reasons: + * - a credential reference will result in + * a prison not being removed + * - setting mnt_exjail NULL indicates that + * the exports are no longer valid + * The now invalid exports will be deleted + * when the file system is dismounted or + * the file system is re-exported by mountd. + */ + cr = NULL; + MNT_ILOCK(mp); + if (mp->mnt_exjail != NULL && + mp->mnt_exjail->cr_prison == pr) { + cr = mp->mnt_exjail; + mp->mnt_exjail = NULL; + } + MNT_IUNLOCK(mp); + if (cr != NULL) { + crfree(cr); + i--; + } + if (i == 0) + break; + continue; + } + cr = NULL; + lockmgr(&mp->mnt_explock, LK_EXCLUSIVE, NULL); + MNT_ILOCK(mp); + if (mp->mnt_exjail != NULL && + mp->mnt_exjail->cr_prison == pr) { + cr = mp->mnt_exjail; + mp->mnt_exjail = NULL; + mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED); + MNT_IUNLOCK(mp); + vfs_free_addrlist(mp->mnt_export); + free(mp->mnt_export, M_MOUNT); + mp->mnt_export = NULL; + } else + MNT_IUNLOCK(mp); + lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); + if (cr != NULL) { + crfree(cr); + i--; + } + mtx_lock(&mountlist_mtx); + vfs_unbusy(mp); + if (i == 0) + break; + goto tryagain; + } + MNT_IUNLOCK(mp); + } + mtx_unlock(&mountlist_mtx); +} + /* * Set the publicly exported filesystem (WebNFS). Currently, only * one public filesystem is possible in the spec (RFC 2054 and 2055) diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c index 430bafc8502f..a3990b9203dd 100644 --- a/sys/kern/vfs_mount.c +++ b/sys/kern/vfs_mount.c @@ -761,6 +761,11 @@ vfs_mount_destroy(struct mount *mp) #endif if (mp->mnt_opt != NULL) vfs_freeopts(mp->mnt_opt); + if (mp->mnt_exjail != NULL) { + atomic_subtract_int(&mp->mnt_exjail->cr_prison->pr_exportcnt, + 1); + crfree(mp->mnt_exjail); + } if (mp->mnt_export != NULL) { vfs_free_addrlist(mp->mnt_export); free(mp->mnt_export, M_MOUNT); @@ -1395,7 +1400,7 @@ vfs_domount_update( } else export_error = EINVAL; if (export_error == 0) - export_error = vfs_export(mp, &export); + export_error = vfs_export(mp, &export, true); free(export.ex_groups, M_TEMP); break; case (sizeof(export)): @@ -1417,7 +1422,7 @@ vfs_domount_update( else export_error = EINVAL; if (export_error == 0) - export_error = vfs_export(mp, &export); + export_error = vfs_export(mp, &export, true); free(grps, M_TEMP); break; default: diff --git a/sys/sys/jail.h b/sys/sys/jail.h index c50c8607aa0a..0a5a7c3288d7 100644 --- a/sys/sys/jail.h +++ b/sys/sys/jail.h @@ -196,7 +196,8 @@ struct prison { int pr_enforce_statfs; /* (p) statfs permission */ int pr_devfs_rsnum; /* (p) devfs ruleset */ enum prison_state pr_state; /* (q) state in life cycle */ - int pr_spare[2]; + volatile int pr_exportcnt; /* (r) count of mount exports */ + int pr_spare; int pr_osreldate; /* (c) kern.osreldate value */ unsigned long pr_hostid; /* (p) jail hostid */ char pr_name[MAXHOSTNAMELEN]; /* (p) admin jail name */ diff --git a/sys/sys/mount.h b/sys/sys/mount.h index 5f02f261b8f4..8dc28a9e0ed9 100644 --- a/sys/sys/mount.h +++ b/sys/sys/mount.h @@ -216,6 +216,7 @@ struct mount_upper_node { * i - interlock * v - vnode freelist mutex * d - deferred unmount list mutex + * e - mnt_explock * * Unmarked fields are considered stable as long as a ref is held. * @@ -245,13 +246,14 @@ struct mount { void * mnt_data; /* private data */ time_t mnt_time; /* last time written*/ int mnt_iosize_max; /* max size for clusters, etc */ - struct netexport *mnt_export; /* export list */ + struct netexport *mnt_export; /* (e) export list */ struct label *mnt_label; /* MAC label for the fs */ u_int mnt_hashseed; /* Random seed for vfs_hash */ int mnt_lockref; /* (i) Lock reference count */ int mnt_secondary_writes; /* (i) # of secondary writes */ int mnt_secondary_accwrites;/* (i) secondary wr. starts */ struct thread *mnt_susp_owner; /* (i) thread owning suspension */ + struct ucred *mnt_exjail; /* (i) jail which did exports */ #define mnt_endzero mnt_gjprovider char *mnt_gjprovider; /* gjournal provider name */ struct mtx mnt_listmtx; @@ -1015,8 +1017,9 @@ int vfs_setpublicfs /* set publicly exported fs */ (struct mount *, struct netexport *, struct export_args *); void vfs_periodic(struct mount *, int); int vfs_busy(struct mount *, int); +void vfs_exjail_delete(struct prison *); int vfs_export /* process mount export info */ - (struct mount *, struct export_args *); + (struct mount *, struct export_args *, bool); void vfs_free_addrlist(struct netexport *); void vfs_allocate_syncvnode(struct mount *); void vfs_deallocate_syncvnode(struct mount *);