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If configured as AD DC and aio_pthread appended into 'vfs objects'[1], run these commands would get segfault: 1. sudo samba-tool ntacl get . 2. sudo net vfs getntacl sysvol . gdb said it goes through aio_pthread_openat_fn() @ vfs_aio_pthread.c[2], and the fsp->conn->sconn->client is null (0x0). 'sconn->client' memory is allocated when a new connection is accpeted: smbd_accept_connection > smbd_process > smbXsrv_client_create While running local commands looks like it would not go through smbXsrv_client_create so the 'client' is null, segfault might happen. We should not dereference 'client->server_multi_channel_enabled', if 'client' is null. BUG: https://bugzilla.samba.org/show_bug.cgi?id=15441 [1] smb.conf example, samba-4.18.5, ubuntu 22.04.2 [global] dns forwarder = 127.0.0.53 netbios name = U22-JONES-88X1 realm = U22-JONES-88X1.X88X1.JONES server role = active directory domain controller workgroup = X88X1 idmap_ldb:use rfc2307 = yes vfs objects = dfs_samba4 acl_xattr aio_pthread [sysvol] path = /var/lib/samba/sysvol read only = No [netlogon] path = /var/lib/samba/sysvol/u22-jones-88x1.x88x1.jones/scripts read only = No [2] gdb (gdb) run /usr/local/samba/bin/samba-tool ntacl get . Starting program: /usr/local/Python3/bin/python3 /usr/local/samba/bin/samba-tool ntacl get . [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/libthread_db.so.1". Program received signal SIGSEGV, Segmentation fault. 0x00007fffd0eb809e in aio_pthread_openat_fn (handle=0x8d5cc0, dirfsp=0x8c3070, smb_fname=0x18ab4f0, fsp=0x1af3550, flags=196608, mode=0) at ../../source3/modules/vfs_aio_pthread.c:467 warning: Source file is more recent than executable. 467 if (fsp->conn->sconn->client->server_multi_channel_enabled) { (gdb) bt at ../../source3/modules/vfs_aio_pthread.c:467 at ../../source3/smbd/pysmbd.c:320 ---Type <return> to continue, or q <return> to quit--- (gdb) f at ../../source3/modules/vfs_aio_pthread.c:467 467 if (fsp->conn->sconn->client->server_multi_channel_enabled) { (gdb) p fsp->conn->sconn->client $1 = (struct smbXsrv_client *) 0x0 (gdb) Signed-off-by: Jones Syue <jonessyue@qnap.com> Reviewed-by: Ralph Boehme <slow@samba.org> Reviewed-by: Stefan Metzmacher <metze@samba.org> |
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.. | ||
getdate.c | ||
getdate.h | ||
getdate.y | ||
hash_inode.c | ||
hash_inode.h | ||
lib_vxfs.c | ||
nfs4_acls.c | ||
nfs4_acls.h | ||
nfs4acl_xattr_ndr.c | ||
nfs4acl_xattr_ndr.h | ||
nfs4acl_xattr_nfs.c | ||
nfs4acl_xattr_nfs.h | ||
nfs4acl_xattr_util.c | ||
nfs4acl_xattr_util.h | ||
nfs4acl_xattr_xdr.c | ||
nfs4acl_xattr_xdr.h | ||
nfs4acl_xattr.h | ||
nfs41acl.x | ||
non_posix_acls.c | ||
non_posix_acls.h | ||
offload_token.c | ||
offload_token.h | ||
posixacl_xattr.c | ||
posixacl_xattr.h | ||
README-gpfs-acl.txt | ||
README.nfs4acls.txt | ||
test_nfs4_acls.c | ||
test_vfs_full_audit.c | ||
test_vfs_gpfs.c | ||
test_vfs_posixacl.c | ||
The_New_VFS.org | ||
The_New_VFS.txt | ||
util_reparse.c | ||
util_reparse.h | ||
vfs_acl_common.c | ||
vfs_acl_common.h | ||
vfs_acl_tdb.c | ||
vfs_acl_xattr.c | ||
vfs_afsacl.c | ||
vfs_aio_fork.c | ||
vfs_aio_pthread.c | ||
vfs_aixacl2.c | ||
vfs_aixacl_util.c | ||
vfs_aixacl_util.h | ||
vfs_aixacl.c | ||
vfs_aixacl.h | ||
vfs_audit.c | ||
vfs_btrfs.c | ||
vfs_cacheprime.c | ||
vfs_cap.c | ||
vfs_catia.c | ||
vfs_ceph_snapshots.c | ||
vfs_ceph.c | ||
vfs_commit.c | ||
vfs_crossrename.c | ||
vfs_default_quota.c | ||
vfs_default.c | ||
vfs_delay_inject.c | ||
vfs_dfs_samba4.c | ||
vfs_dirsort.c | ||
vfs_error_inject.c | ||
vfs_expand_msdfs.c | ||
vfs_extd_audit.c | ||
vfs_fake_acls.c | ||
vfs_fake_dfq.c | ||
vfs_fake_perms.c | ||
vfs_fileid.c | ||
vfs_fruit.c | ||
vfs_full_audit.c | ||
vfs_glusterfs_fuse.c | ||
vfs_glusterfs.c | ||
vfs_gpfs.c | ||
vfs_hpuxacl.c | ||
vfs_hpuxacl.h | ||
vfs_io_uring.c | ||
vfs_linux_xfs_sgid.c | ||
vfs_media_harmony.c | ||
vfs_nfs4acl_xattr.c | ||
vfs_not_implemented.c | ||
vfs_offline.c | ||
vfs_posix_eadb.c | ||
vfs_posixacl.c | ||
vfs_posixacl.h | ||
vfs_prealloc.c | ||
vfs_preopen.c | ||
vfs_readahead.c | ||
vfs_readonly.c | ||
vfs_recycle.c | ||
vfs_shadow_copy2.c | ||
vfs_shadow_copy.c | ||
vfs_shell_snap.c | ||
vfs_snapper.c | ||
vfs_solarisacl.c | ||
vfs_solarisacl.h | ||
vfs_streams_depot.c | ||
vfs_streams_xattr.c | ||
vfs_syncops.c | ||
vfs_time_audit.c | ||
vfs_tsmsm.c | ||
vfs_unityed_media.c | ||
vfs_virusfilter_clamav.c | ||
vfs_virusfilter_common.h | ||
vfs_virusfilter_dummy.c | ||
vfs_virusfilter_fsav.c | ||
vfs_virusfilter_sophos.c | ||
vfs_virusfilter_utils.c | ||
vfs_virusfilter_utils.h | ||
vfs_virusfilter.c | ||
vfs_vxfs.c | ||
vfs_vxfs.h | ||
vfs_widelinks.c | ||
vfs_worm.c | ||
vfs_xattr_tdb.c | ||
vfs_zfsacl.c | ||
wscript_build |
Configuring NFS4 ACLs in Samba3 =============================== Created: Peter Somogyi, 2006-JUN-06 Last modified: Alexander Werth, 2013-MAY-02 Revision no.: 4 ------------------------------- Parameters in smb.conf: ======================= Each parameter must have a prefix "nfs4:". Each one affects the behaviour only when _setting_ an acl on a file/dir: mode = [simple|special] - simple: Use OWNER@ and GROUP@ special IDs for non inheriting ACEs only. This mode is the default. - special: use OWNER@ and GROUP@ special IDs in ACEs instead of simple user&group ids. This mode is deprecated. Note1: EVERYONE@ is always processed (if found such an ACE). Note2: There is a side effect when _only_ chown is performed. Later this may be worked out. Note3: Mode special inherits incorrect ACL entries when the user creating a file is different from the owner of the caurrent folder. Note4: Mode simple uses inheriting OWNER@ and GROUP@ special IDs to support Creator Owner and Creator Group. It's strongly advised to set "store dos attributes = yes" in smb.conf. chown = [true|false] - true => enable changing owner and group - default. - false => disable support for changing owner or group acedup = [dontcare|reject|ignore|merge] - dontcare: copy ACEs as they come, don't care with "duplicate" records. - reject: stop operation, exit acl setter operation with an error. (deprecated) - ignore: don't include the second matching ACE. (deprecated) - merge: OR 2 ace.flag fields and 2 ace.mask fields of the 2 duplicate ACEs into 1 ACE (default) Two ACEs are considered here "duplicate" when their type and id fields are matching. Example: [smbtest] path = /tests/psomogyi/smbtest writable = yes vfs objects = aixacl2 nfs4: mode = special nfs4: chown = yes nfs4: acedup = merge Configuring AIX ACL support ============================== Binaries: (default install path is [samba]/lib/vfs/) - aixacl.so: provides AIXC ACL support only, can be compiled and works on all AIX platforms - aixacl2.so: provides AIXC and JFS2-NFS4 ACL support, can be compiled and works only under AIX 5.3 and newer. NFS4 acl currently has support only under JFS2 (ext. attr. format must be set to v2). aixacl2.so always detects support for NFS4 acls and redirects to POSIX ACL handling automatically when NFS4 is not supported for a path. Adding "vfs objects = aixacl2" to a share should be done only in case when NFS4 is really supported by the filesystem. (Otherwise you may get performance loss.) For configuration see also the example above. General notes ============= NFS4 handling logic is separated from AIX/jfs2 ACL parsing. Samba and its VFS modules don't reorder ACEs. Windows clients do that (and the smbcacl tool). MSDN also says deny ACEs must come first. NFS4 ACL's validity is checked by the system API, not by Samba. NFS4 ACL rights are enforced by the OS or filesystem, not by Samba. The flag INHERITED_ACE is never set (not required, as doesn't do WinNT/98/me, only since Win2k). Win2k GUI behaves strangely when detecting inheritance (sometimes it doesn't detect, but after adding an ace it shows that - it's some GUI error). Unknown (unmappable) SIDs are not accepted. TODOs ===== - Creator Owner & Group SID handling (same way as posix) - the 4 generic rights bits support (GENERIC_RIGHT_READ_ACCESS, WRITE, EXEC, ALL) - chown & no ACL, but we have OWNER@ and GROUP@ - DIALUP, ANONYMOUS, ... builtin SIDs - audit & alarm support - in theory it's forwarded so it should work, but currently there's no platform which supports them to test - support for a real NFS4 client (we don't have an accepted API yet)