From 2475e8c9d3db9743065e38bfd6da87332a1d74a7 Mon Sep 17 00:00:00 2001 From: Michael Adam Date: Mon, 2 Sep 2013 17:36:59 +0200 Subject: [PATCH 1/3] loadparm: add new parameter "acl allow execute always" Signed-off-by: Michael Adam Reviewed-by: Volker Lendecke Reviewed-by: David Disseldorp --- lib/param/param_functions.c | 1 + lib/param/param_table.c | 10 ++++++++++ source3/include/proto.h | 1 + source3/param/loadparm.c | 1 + 4 files changed, 13 insertions(+) diff --git a/lib/param/param_functions.c b/lib/param/param_functions.c index 94652fa..35e199f 100644 --- a/lib/param/param_functions.c +++ b/lib/param/param_functions.c @@ -134,6 +134,7 @@ FN_LOCAL_BOOL(afs_share, bAfs_Share) FN_LOCAL_BOOL(acl_check_permissions, bAclCheckPermissions) FN_LOCAL_BOOL(acl_group_control, bAclGroupControl) FN_LOCAL_BOOL(acl_map_full_control, bAclMapFullControl) +FN_LOCAL_BOOL(acl_allow_execute_always, bAclAllowExecuteAlways) FN_LOCAL_INTEGER(defaultcase, iDefaultCase) FN_LOCAL_INTEGER(minprintspace, iMinPrintSpace) FN_LOCAL_INTEGER(printing, iPrinting) diff --git a/lib/param/param_table.c b/lib/param/param_table.c index a73cd96..5b78eae 100644 --- a/lib/param/param_table.c +++ b/lib/param/param_table.c @@ -920,6 +920,16 @@ static struct parm_struct parm_table[] = { .flags = FLAG_ADVANCED | FLAG_GLOBAL | FLAG_SHARE, }, { + .label = "acl allow execute always", + .type = P_BOOL, + .p_class = P_LOCAL, + .offset = LOCAL_VAR(bAclAllowExecuteAlways), + .special = NULL, + .enum_list = NULL, + .flags = FLAG_ADVANCED | FLAG_GLOBAL | FLAG_SHARE, + }, + + { .label = "create mask", .type = P_OCTAL, .p_class = P_LOCAL, diff --git a/source3/include/proto.h b/source3/include/proto.h index 5f34193..0defbc9 100644 --- a/source3/include/proto.h +++ b/source3/include/proto.h @@ -1326,6 +1326,7 @@ bool lp_afs_share(int ); bool lp_acl_check_permissions(int ); bool lp_acl_group_control(int ); bool lp_acl_map_full_control(int ); +bool lp_acl_allow_execute_always(int); bool lp_durable_handles(int); int lp_create_mask(int ); int lp_force_create_mode(int ); diff --git a/source3/param/loadparm.c b/source3/param/loadparm.c index e09c2bf..2e05bac 100644 --- a/source3/param/loadparm.c +++ b/source3/param/loadparm.c @@ -264,6 +264,7 @@ static struct loadparm_service sDefault = .bAclCheckPermissions = true, .bAclMapFullControl = true, .bAclGroupControl = false, + .bAclAllowExecuteAlways = false, .bChangeNotify = true, .bKernelChangeNotify = true, .iallocation_roundup_size = SMB_ROUNDUP_ALLOCATION_SIZE, -- 1.7.9.5 From b92b0f9700aacd66b5c094eff7efb311fc7e61b4 Mon Sep 17 00:00:00 2001 From: Michael Adam Date: Mon, 2 Sep 2013 17:37:50 +0200 Subject: [PATCH 2/3] s3:smbd: ease file server upgrades from 3.6 and earlier with "acl allow execute aways" 3.6 and earlier allowed open for execution when execute permissions are not present on a file. This has been fixed in Samba 4.0. This patch changes smbd to skip the execute bit from the ACL check in the open code if "acl allow execute always = yes", hence re-establishing the old behaviour in this case. Signed-off-by: Michael Adam Reviewed-by: Volker Lendecke Reviewed-by: David Disseldorp --- source3/smbd/open.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/source3/smbd/open.c b/source3/smbd/open.c index 16ca34a..0eb1ec2 100644 --- a/source3/smbd/open.c +++ b/source3/smbd/open.c @@ -74,6 +74,7 @@ NTSTATUS smbd_check_access_rights(struct connection_struct *conn, struct security_descriptor *sd = NULL; uint32_t rejected_share_access; uint32_t rejected_mask = access_mask; + uint32_t do_not_check_mask = 0; rejected_share_access = access_mask & ~(conn->share_access); @@ -141,10 +142,23 @@ NTSTATUS smbd_check_access_rights(struct connection_struct *conn, * se_file_access_check() also takes care of * owner WRITE_DAC and READ_CONTROL. */ + do_not_check_mask = FILE_READ_ATTRIBUTES; + + /* + * Samba 3.6 and earlier granted execute access even + * if the ACL did not contain execute rights. + * Samba 4.0 is more correct and checks it. + * The compatibilty mode allows to skip this check + * to smoothen upgrades. + */ + if (lp_acl_allow_execute_always(SNUM(conn))) { + do_not_check_mask |= FILE_EXECUTE; + } + status = se_file_access_check(sd, get_current_nttok(conn), false, - (access_mask & ~FILE_READ_ATTRIBUTES), + (access_mask & ~do_not_check_mask), &rejected_mask); DEBUG(10,("smbd_check_access_rights: file %s requesting " -- 1.7.9.5 From 121c19cb7e04c6a2f6a1dba7089fcea67073a212 Mon Sep 17 00:00:00 2001 From: Michael Adam Date: Mon, 2 Sep 2013 16:54:15 +0200 Subject: [PATCH 3/3] docs: document "acl allow execute always" Signed-off-by: Michael Adam Reviewed-by: Volker Lendecke Reviewed-by: David Disseldorp --- .../smbdotconf/protocol/aclallowexecutealways.xml | 26 ++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 docs-xml/smbdotconf/protocol/aclallowexecutealways.xml diff --git a/docs-xml/smbdotconf/protocol/aclallowexecutealways.xml b/docs-xml/smbdotconf/protocol/aclallowexecutealways.xml new file mode 100644 index 0000000..048c388 --- /dev/null +++ b/docs-xml/smbdotconf/protocol/aclallowexecutealways.xml @@ -0,0 +1,26 @@ + + + + This boolean parameter controls the behaviour of smbd + 8 when receiving a protocol request of "open for execution" + from a Windows client. + With Samba 3.6 and older, the execution right in the ACL was not checked, so a client + could execute a file even if it did not have execute rights on the file. In Samba 4.0, + this has been fixed, so that by default, i.e. when this parameter is set to "False", + open for execution is now denied when execution permissions are not present. + + + If this parameter is set to "True", Samba does not check execute permissions on + "open for execution, thus re-establishing the behaviour of Samba 3.6. + This can be useful to smoothen upgrades from older Samba versions to 4.0 and newer. + This setting is not not meant to be used as a permanent setting, but as a temporary relief: + It is recommended to fix the permissions in the ACLs and reset this parameter to the + default after a ceratain transition period. + + +False + -- 1.7.9.5