6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexander Wetzel <Alexander@xxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxx Fixes: db59133e9279 ("scsi: sg: fix blktrace debugfs entries leakage") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Alexander Wetzel <Alexander@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20240320213032.18221-1-Alexander@xxxxxxxxxxxxxx Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/scsi/sg.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -2208,6 +2208,7 @@ sg_remove_sfp_usercontext(struct work_st { 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_st "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); }
