diff options
author | Petr Uzel <petr.uzel@suse.cz> | 2011-10-21 07:31:09 -0400 |
---|---|---|
committer | James Bottomley <JBottomley@Parallels.com> | 2011-10-30 05:27:28 -0400 |
commit | c68bf8eeaa57c852e74adcf597237be149eef830 (patch) | |
tree | bd631c9731acc98e562fe202da55b050637c203f /drivers/scsi/st.c | |
parent | 3308511c93e6ad0d3c58984ecd6e5e57f96b12c8 (diff) |
[SCSI] st: fix race in st_scsi_execute_end
The call to complete() in st_scsi_execute_end() wakes up sleeping thread
in write_behind_check(), which frees the st_request, thus invalidating
the pointer to the associated bio structure, which is then passed to the
blk_rq_unmap_user(). Fix by storing pointer to bio structure into
temporary local variable.
This bug is present since at least linux-2.6.32.
CC: stable@kernel.org
Signed-off-by: Petr Uzel <petr.uzel@suse.cz>
Reported-by: Juergen Groß <juergen.gross@ts.fujitsu.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/st.c')
-rw-r--r-- | drivers/scsi/st.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index 1871b8ae83ae..9b28f39bac26 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c | |||
@@ -462,14 +462,16 @@ static void st_scsi_execute_end(struct request *req, int uptodate) | |||
462 | { | 462 | { |
463 | struct st_request *SRpnt = req->end_io_data; | 463 | struct st_request *SRpnt = req->end_io_data; |
464 | struct scsi_tape *STp = SRpnt->stp; | 464 | struct scsi_tape *STp = SRpnt->stp; |
465 | struct bio *tmp; | ||
465 | 466 | ||
466 | STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors; | 467 | STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors; |
467 | STp->buffer->cmdstat.residual = req->resid_len; | 468 | STp->buffer->cmdstat.residual = req->resid_len; |
468 | 469 | ||
470 | tmp = SRpnt->bio; | ||
469 | if (SRpnt->waiting) | 471 | if (SRpnt->waiting) |
470 | complete(SRpnt->waiting); | 472 | complete(SRpnt->waiting); |
471 | 473 | ||
472 | blk_rq_unmap_user(SRpnt->bio); | 474 | blk_rq_unmap_user(tmp); |
473 | __blk_put_request(req->q, req); | 475 | __blk_put_request(req->q, req); |
474 | } | 476 | } |
475 | 477 | ||