diff options
| author | Alexander Wetzel <Alexander@wetzel-home.de> | 2024-03-20 22:30:32 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-17 11:19:34 +0200 |
| commit | 46af9047523e2517712ae8e71d984286c626e022 (patch) | |
| tree | 4e78fcb54fd6e817028e206ce66be94044736f34 | |
| parent | d15023fb407337028a654237d8968fefdcf87c2f (diff) | |
scsi: sg: Avoid sg device teardown race
commit 27f58c04a8f438078583041468ec60597841284d upstream.
sg_remove_sfp_usercontext() must not use sg_device_destroy() after calling
scsi_device_put().
sg_device_destroy() is accessing the parent scsi_device request_queue which
will already be set to NULL when the preceding call to scsi_device_put()
removed the last reference to the parent scsi_device.
The resulting NULL pointer exception will then crash the kernel.
Link: https://lore.kernel.org/r/20240305150509.23896-1-Alexander@wetzel-home.de
Fixes: db59133e9279 ("scsi: sg: fix blktrace debugfs entries leakage")
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Wetzel <Alexander@wetzel-home.de>
Link: https://lore.kernel.org/r/20240320213032.18221-1-Alexander@wetzel-home.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/scsi/sg.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 0d8afffd1683..8bd95ee1825a 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -2208,6 +2208,7 @@ sg_remove_sfp_usercontext(struct work_struct *work) { struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work); struct sg_device *sdp = sfp->parentdp; + struct scsi_device *device = sdp->device; Sg_request *srp; unsigned long iflags; @@ -2233,8 +2234,9 @@ sg_remove_sfp_usercontext(struct work_struct *work) "sg_remove_sfp: sfp=0x%p\n", sfp)); kfree(sfp); - scsi_device_put(sdp->device); + WARN_ON_ONCE(kref_read(&sdp->d_ref) != 1); kref_put(&sdp->d_ref, sg_device_destroy); + scsi_device_put(device); module_put(THIS_MODULE); } |