From 64c0367335fab0137e65f8cfa35af77ff854f654 Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Tue, 7 Aug 2012 22:25:53 +0200 Subject: [PATCH] s3: Fix a crash in reply_lockingX_error A timed brlock with 2 locks comes in and the second one blocks, file is closed. smbd_cancel_pending_lock_requests_by_fid sets blr->fsp to NULL. reply_lockingX_error (called via MSG_SMB_BLOCKING_LOCK_CANCEL) deferences blr->fsp because blr->lock_num==1 (the second one blocked). This patch fixes the bug by only undoing the locks if fsp!=NULL. fsp==NULL is the close case where everything is undone anyway. Thanks to Peter Somogyi, somogyi@hu.ibm.com for this bug report. Autobuild-User(master): Jeremy Allison Autobuild-Date(master): Wed Aug 8 04:12:04 CEST 2012 on sn-devel-104 --- source3/smbd/blocking.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/source3/smbd/blocking.c b/source3/smbd/blocking.c index 3a45a275aa8..95d6c330a0e 100644 --- a/source3/smbd/blocking.c +++ b/source3/smbd/blocking.c @@ -336,7 +336,7 @@ static void generic_blocking_lock_error(struct blocking_lock_record *blr, NTSTAT obtained first. *****************************************************************************/ -static void reply_lockingX_error(struct blocking_lock_record *blr, NTSTATUS status) +static void undo_locks_obtained(struct blocking_lock_record *blr) { files_struct *fsp = blr->fsp; uint16 num_ulocks = SVAL(blr->req->vwv+6, 0); @@ -380,8 +380,6 @@ static void reply_lockingX_error(struct blocking_lock_record *blr, NTSTATUS stat offset, WINDOWS_LOCK); } - - generic_blocking_lock_error(blr, status); } /**************************************************************************** @@ -394,7 +392,16 @@ static void blocking_lock_reply_error(struct blocking_lock_record *blr, NTSTATUS switch(blr->req->cmd) { case SMBlockingX: - reply_lockingX_error(blr, status); + /* + * This code can be called during the rundown of a + * file after it was already closed. In that case, + * blr->fsp==NULL and we do not need to undo any + * locks, they are already gone. + */ + if (blr->fsp != NULL) { + undo_locks_obtained(blr); + } + generic_blocking_lock_error(blr, status); break; case SMBtrans2: case SMBtranss2: -- 2.11.4.GIT