Attachment 13513 Details for Bug 12995 – Possible patch for master

[patch] Possible patch for master

wip (text/plain), 3.25 KB, created by Ralph Böhme on 2017-08-29 14:16:19 UTC

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Creator: Ralph Böhme

Created: 2017-08-29 14:16:19 UTC

Size: 3.25 KB

patch

obsolete

>From bef82d3180a6df98623664eaed8a7ae51159573b Mon Sep 17 00:00:00 2001
>From: Ralph Boehme <slow@samba.org>
>Date: Tue, 29 Aug 2017 15:55:19 +0200
>Subject: [PATCH 1/3] s3/smbd: remove lp_dos_filemode() check from permissions
> override
>
>We wanted to set the DOS attributes and failed with permission
>denied. Next thing we wanna do here is possible override the kernel
>access check given that the stored security descriptor has
>FILE_WRITE_ATTRIBUTES for the user.
>
>All this has nothing to do with what the "dos filemode" setting is for,
>so just remove it from this codepath.
>
>Bug: ...
>---
> source3/smbd/dosmode.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/source3/smbd/dosmode.c b/source3/smbd/dosmode.c
>index 3181f2e78a9..72980679266 100644
>--- a/source3/smbd/dosmode.c
>+++ b/source3/smbd/dosmode.c
>@@ -475,7 +475,7 @@ NTSTATUS set_ea_dos_attribute(connection_struct *conn,
> 		*/
> 
> 		/* Check if we have write access. */
>-		if(!CAN_WRITE(conn) || !lp_dos_filemode(SNUM(conn)))
>+		if(!CAN_WRITE(conn))
> 			return NT_STATUS_ACCESS_DENIED;
> 
> 		if (!can_write_to_file(conn, smb_fname)) {
>-- 
>2.13.5
>
>
>From 09905d6ccb73a437d6f4d68072bfe3899d049a9b Mon Sep 17 00:00:00 2001
>From: Ralph Boehme <slow@samba.org>
>Date: Tue, 29 Aug 2017 15:57:49 +0200
>Subject: [PATCH 2/3] s3/smbd: setting DOS attributes requires
> FILE_WRITE_ATTRIBUTES
>
>can_write_to_file() tests for FILE_WRITE_DATA, but changing DOS
>attributes requires FILE_WRITE_ATTRIBUTES.
>
>Bug: ...
>---
> source3/smbd/dosmode.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
>diff --git a/source3/smbd/dosmode.c b/source3/smbd/dosmode.c
>index 72980679266..420afd0697f 100644
>--- a/source3/smbd/dosmode.c
>+++ b/source3/smbd/dosmode.c
>@@ -478,7 +478,9 @@ NTSTATUS set_ea_dos_attribute(connection_struct *conn,
> 		if(!CAN_WRITE(conn))
> 			return NT_STATUS_ACCESS_DENIED;
> 
>-		if (!can_write_to_file(conn, smb_fname)) {
>+		status = smbd_check_access_rights(conn, smb_fname, false,
>+						  FILE_WRITE_ATTRIBUTES);
>+		if (!NT_STATUS_IS_OK(status)) {
> 			return NT_STATUS_ACCESS_DENIED;
> 		}
> 
>-- 
>2.13.5
>
>
>From ed9f9bd75794bb7cec074f5c4116f132998a837c Mon Sep 17 00:00:00 2001
>From: Ralph Boehme <slow@samba.org>
>Date: Tue, 29 Aug 2017 16:08:06 +0200
>Subject: [PATCH 3/3] s3/smbd: let get_file_handle_for_metadata() open the file
> read-only
>
>We're only using these filehandles in root override cases where we need
>a filehandle to call filehandle based syscalls (fchmod and
>fsetxattr). This fixes the case of requesting write access on a file
>where the user only has read permissions which fails.
>
>Bug: ...
>---
> source3/smbd/dosmode.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/source3/smbd/dosmode.c b/source3/smbd/dosmode.c
>index 420afd0697f..38d92e8fa2f 100644
>--- a/source3/smbd/dosmode.c
>+++ b/source3/smbd/dosmode.c
>@@ -1154,7 +1154,7 @@ static NTSTATUS get_file_handle_for_metadata(connection_struct *conn,
> 		NULL,                                   /* req */
> 		0,                                      /* root_dir_fid */
> 		smb_fname_cp,				/* fname */
>-		FILE_WRITE_DATA,                        /* access_mask */
>+		FILE_READ_DATA,				/* access_mask */
> 		(FILE_SHARE_READ | FILE_SHARE_WRITE |   /* share_access */
> 			FILE_SHARE_DELETE),
> 		FILE_OPEN,                              /* create_disposition*/
>-- 
>2.13.5
>

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Attachments on bug 12995: 13513 | 13650 | 13683 | 13701 | 13702