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| author | Volker Lendecke <vl@samba.org> | 2012-08-07 22:25:53 +0200 |
|---|---|---|
| committer | Jeremy Allison <jra@samba.org> | 2012-08-08 04:12:04 +0200 |
| commit | 64c0367335fab0137e65f8cfa35af77ff854f654 (patch) | |
| tree | a7a2d06943761f2b541d94ef73145205d09c0f7c | |
| parent | c2dee12d678234126648d150f6f03165a2b7c95b (diff) | |
| download | samba-64c0367335fab0137e65f8cfa35af77ff854f654.tar.gz samba-64c0367335fab0137e65f8cfa35af77ff854f654.tar.bz2 samba-64c0367335fab0137e65f8cfa35af77ff854f654.zip | |
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 <jra@samba.org>
Autobuild-Date(master): Wed Aug 8 04:12:04 CEST 2012 on sn-devel-104
| -rw-r--r-- | source3/smbd/blocking.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/source3/smbd/blocking.c b/source3/smbd/blocking.c index 3a45a275aa..95d6c330a0 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: |