diff options
| author | Alexander Wetzel <[email protected]> | 2024-03-20 22:30:32 +0100 |
|---|---|---|
| committer | Martin K. Petersen <[email protected]> | 2024-03-25 15:41:07 -0400 |
| commit | 27f58c04a8f438078583041468ec60597841284d (patch) | |
| tree | b577c903f5887be0875f9bc597ab4efaa96c18ee | |
| parent | f02fe780f28db435671fcc7c0214556e253b5a46 (diff) | |
scsi: sg: Avoid sg device teardown race
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/[email protected]
Fixes: db59133e9279 ("scsi: sg: fix blktrace debugfs entries leakage")
Cc: [email protected]
Signed-off-by: Alexander Wetzel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Bart Van Assche <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
| -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 6ef6256246df..386981c6976a 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -2207,6 +2207,7 @@ 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; @@ -2232,8 +2233,9 @@ 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); } |