diff options
author | Mike Snitzer <snitzer@redhat.com> | 2018-09-17 18:38:47 +0300 |
---|---|---|
committer | Mike Snitzer <snitzer@redhat.com> | 2018-09-18 05:46:49 +0300 |
commit | b592211c33f745af67a3271ce77c10fc1e6d6241 (patch) | |
tree | e7d3f619055d7c721b4a32b3af14e070cfd21c4e /drivers/md/dm-mpath.c | |
parent | 013ad043906b2befd4a9bfb06219ed9fedd92716 (diff) |
dm mpath: fix attached_handler_name leak and dangling hw_handler_name pointer
Commit e8f74a0f0011 ("dm mpath: eliminate need to use
scsi_device_from_queue") introduced 2 regressions:
1) memory leak occurs if attached_handler_name is not assigned to
m->hw_handler_name
2) m->hw_handler_name can become a dangling pointer if the
RETAIN_ATTACHED_HW_HANDLER flag is set and scsi_dh_attach() returns
-EBUSY.
Fix both of these by clearing 'attached_handler_name' pointer passed to
setup_scsi_dh() after it is assigned to m->hw_handler_name. And if
setup_scsi_dh() doesn't consume 'attached_handler_name' parse_path()
will kfree() it.
Fixes: e8f74a0f0011 ("dm mpath: eliminate need to use scsi_device_from_queue")
Cc: stable@vger.kernel.org # 4.16+
Reported-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-mpath.c')
-rw-r--r-- | drivers/md/dm-mpath.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index d94ba6f72ff5..419362c2d8ac 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -806,19 +806,19 @@ static int parse_path_selector(struct dm_arg_set *as, struct priority_group *pg, } static int setup_scsi_dh(struct block_device *bdev, struct multipath *m, - const char *attached_handler_name, char **error) + const char **attached_handler_name, char **error) { struct request_queue *q = bdev_get_queue(bdev); int r; if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags)) { retain: - if (attached_handler_name) { + if (*attached_handler_name) { /* * Clear any hw_handler_params associated with a * handler that isn't already attached. */ - if (m->hw_handler_name && strcmp(attached_handler_name, m->hw_handler_name)) { + if (m->hw_handler_name && strcmp(*attached_handler_name, m->hw_handler_name)) { kfree(m->hw_handler_params); m->hw_handler_params = NULL; } @@ -830,7 +830,8 @@ retain: * handler instead of the original table passed in. */ kfree(m->hw_handler_name); - m->hw_handler_name = attached_handler_name; + m->hw_handler_name = *attached_handler_name; + *attached_handler_name = NULL; } } @@ -867,7 +868,7 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps struct pgpath *p; struct multipath *m = ti->private; struct request_queue *q; - const char *attached_handler_name; + const char *attached_handler_name = NULL; /* we need at least a path arg */ if (as->argc < 1) { @@ -890,7 +891,7 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL); if (attached_handler_name || m->hw_handler_name) { INIT_DELAYED_WORK(&p->activate_path, activate_path_work); - r = setup_scsi_dh(p->path.dev->bdev, m, attached_handler_name, &ti->error); + r = setup_scsi_dh(p->path.dev->bdev, m, &attached_handler_name, &ti->error); if (r) { dm_put_device(ti, p->path.dev); goto bad; @@ -905,6 +906,7 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps return p; bad: + kfree(attached_handler_name); free_pgpath(p); return ERR_PTR(r); } |