From f8af6870a061758a37bb6c63d09ce23ab971c6ce Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Tue, 24 Jun 2014 14:19:30 -0700 Subject: [PATCH] s3: smbd - Prevent file truncation on an open that fails with share mode violation. Fix from Volker, really - just tidied up a little. The S_ISFIFO check may not be strictly neccessary, but doesn't hurt (might make the code a bit more complex than it needs to be). Fixes bug #10671 - Samba file corruption as a result of failed lock check. https://bugzilla.samba.org/show_bug.cgi?id=10671 Signed-off-by: Jeremy Allison Reviewed-by: Volker Lendecke Reviewed-by: David Disseldorp (cherry picked from commit 31b3427a417217e5e869baafdf63e633efc39d12) [ddiss@samba.org: 4.1 backport] --- source3/smbd/open.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/source3/smbd/open.c b/source3/smbd/open.c index 5f7bff9a8d3..72b8b598310 100644 --- a/source3/smbd/open.c +++ b/source3/smbd/open.c @@ -839,8 +839,11 @@ static NTSTATUS open_file(files_struct *fsp, } } - /* Actually do the open */ - status = fd_open_atomic(conn, fsp, local_flags, + /* + * Actually do the open - if O_TRUNC is needed handle it + * below under the share mode lock. + */ + status = fd_open_atomic(conn, fsp, local_flags & ~O_TRUNC, unx_mode, p_file_created); if (!NT_STATUS_IS_OK(status)) { DEBUG(3,("Error opening file %s (%s) (local_flags=%d) " @@ -2646,6 +2649,21 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn, return status; } + /* Should we atomically (to the client at least) truncate ? */ + if (!new_file_created) { + if (flags2 & O_TRUNC) { + if (!S_ISFIFO(fsp->fsp_name->st.st_ex_mode)) { + int ret = vfs_set_filelen(fsp, 0); + if (ret != 0) { + status = map_nt_error_from_unix(errno); + TALLOC_FREE(lck); + fd_close(fsp); + return status; + } + } + } + } + grant_fsp_oplock_type(fsp, oplock_request, got_level2_oplock, -- 2.11.4.GIT