From nobody Fri May 19 20:22:31 2023 X-Original-To: dev-commits-src-branches@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 4QNJDR3VjQz4CLDF; Fri, 19 May 2023 20:22:31 +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 4QNJDR2tRwz3Ny2; Fri, 19 May 2023 20:22:31 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1684527751; 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=xjhBaPLT/46Fklg+549r1MlryeAS+dpLFMo5QSYcPFI=; b=kFUTqcXPPEMSjkUPBIhSpIiwMc7/7v9n8UEFcaYC1SAl4FyNEYsy02iH8WeWx9sVyx6oON re8ThxVEOvWs6enBKyFIrrwzBbjCj1DK2C44pRhEvSrZ1Z6g2fwk4hhHikb5lMyktL9SKO hOPqauujimRMss7+WD/i3+mX4p9yi+oixRYNN1wE3SJr3rEF5XaKBpq0mFlBfBqEyi9pFQ V8J56EI6gL5BdQv3jPLtJLJSpBCjVbwW/3AN0Rx3Zi5zcxIPf8HMGrksPH5bkOeugYUkcq 0mikoUH9UCe263pcndDDCQszNH3PkLWg4RCrVl7qzJdLqdVavJGpg9dh0MAREw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1684527751; 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=xjhBaPLT/46Fklg+549r1MlryeAS+dpLFMo5QSYcPFI=; b=d5QSpcHKCQXElCaQgI7Md34zsSNbygm6oUWgd8GsZUZ2+LWdBAUFN2CJLmAHKGNfgxlzmf 8klOaI3c0P4BY2iR0cGWIzPCKX6y2QoAR/BaXGIeEEfL7TdNDchUQ4jyMWO7RhBXaf7txd Xdo+jyHzVAwNNjb3MpZcHYTFRgGMR+kINnP79AkIOFqOgtD1lQ1VcJ7i25PlJ9LyscL+Av 1C0o6iIPUILb0ityOW66OajbvEK7Ub4gnln2MpFKBXqbC/Eu33dRlgRKn569i7ucdStZv+ kbQ6+k8JavEMP74Lcu168zYV6nTROW15mJqGhDucE9JHlYUPSVbPVj/HUM8yRA== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1684527751; a=rsa-sha256; cv=none; b=OLpV9YgjUlA6CgaO1ujLh/lUCh96jjK5IO0Qi0em3AN5GI+jl858f9bXFmnBm6OFO9ENst 5zmh1lCkNKw0pA5MHqieAj6pafO9XBQb2wgw+KVV2sS4GsbRY2S7l2/YIcNAOCu1oLjOAx 3Sg9P0kfs91nOsJvXW9vJOjMwyBEi2T3iDKLvbvNW2H1lfLpvLAL2tndwuFqm+0KTO2FNq OsdWDzoiRcpQNFjfX+KOPk3jSOoXxAt0XdxnJ2HzO4wALneIHMwp0cCOVJFgiRbDDekhaD UNcbFzURD1dZt8DRYDRmYljj7S/vgmaj0iQgcvn0gy4IzvEE/armg1/epXrAVA== 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 4QNJDR1wm9zhR0; Fri, 19 May 2023 20:22:31 +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 34JKMVbm018086; Fri, 19 May 2023 20:22:31 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 34JKMVow018085; Fri, 19 May 2023 20:22:31 GMT (envelope-from git) Date: Fri, 19 May 2023 20:22:31 GMT Message-Id: <202305192022.34JKMVow018085@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Rick Macklem Subject: git: 202d52261b92 - stable/13 - vfs_export: Add mnt_exjail to control exports done in prisons List-Id: Commits to the stable branches of the FreeBSD src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-branches List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-branches@freebsd.org X-BeenThere: dev-commits-src-branches@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/stable/13 X-Git-Reftype: branch X-Git-Commit: 202d52261b92abdfb1ec39564ee1be3812bcdf92 Auto-Submitted: auto-generated X-ThisMailContainsUnwantedMimeParts: N The branch stable/13 has been updated by rmacklem: URL: https://cgit.FreeBSD.org/src/commit/?id=202d52261b92abdfb1ec39564ee1be3812bcdf92 commit 202d52261b92abdfb1ec39564ee1be3812bcdf92 Author: Rick Macklem AuthorDate: 2023-02-21 21:00:42 +0000 Commit: Rick Macklem CommitDate: 2023-05-19 20:17:17 +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. mnt_exjail replaces mnt_pad0 and should not change the size of "struct mount" nor change the offsets of the other fields in "struct mount". As such, it should be safe to MFC. (cherry picked from commit 88175af8b75ea8850757cc9dca68b6d336b82675) --- 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 | 5 +- 6 files changed, 192 insertions(+), 14 deletions(-) diff --git a/sys/fs/nfsserver/nfs_nfsdport.c b/sys/fs/nfsserver/nfs_nfsdport.c index 4247177a3fc0..50d3aa57c4aa 100644 --- a/sys/fs/nfsserver/nfs_nfsdport.c +++ b/sys/fs/nfsserver/nfs_nfsdport.c @@ -3270,8 +3270,16 @@ 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; @@ -3305,8 +3313,14 @@ 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; @@ -3476,7 +3490,7 @@ 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 622b9f6c7cb9..0203dcd0faf1 100644 --- a/sys/kern/kern_jail.c +++ b/sys/kern/kern_jail.c @@ -3035,6 +3035,7 @@ 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 d5b137e7ffab..4c941c2616ff 100644 --- a/sys/kern/vfs_mount.c +++ b/sys/kern/vfs_mount.c @@ -618,6 +618,11 @@ 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); @@ -1236,7 +1241,7 @@ 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)): @@ -1258,7 +1263,7 @@ 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 f4d4e521d7de..e81b272677bb 100644 --- a/sys/sys/jail.h +++ b/sys/sys/jail.h @@ -190,7 +190,8 @@ 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 9a69240ddba5..382be23e37e5 100644 --- a/sys/sys/mount.h +++ b/sys/sys/mount.h @@ -222,7 +222,7 @@ struct mount { int mnt_writeopcount; /* (i) write syscalls pending */ struct vfsoptlist *mnt_opt; /* current mount options */ struct vfsoptlist *mnt_optnew; /* new options passed to fs */ - u_int mnt_pad0; /* was mnt_maxsymlinklen */ + struct ucred *mnt_exjail; /* (i) jail which did exports */ struct statfs mnt_stat; /* cache of filesystem stats */ struct ucred *mnt_cred; /* credentials of mounter */ void * mnt_data; /* private data */ @@ -985,8 +985,9 @@ 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 *);