From f1fb41765d0bff77514ffeaef37bbb45608f6c62 Mon Sep 17 00:00:00 2001 From: "Ricardo B. Marliere" Date: Sat, 2 Mar 2024 13:47:22 -0300 Subject: scsi: sg: Make sg_sysfs_class constant Since commit 43a7206b0963 ("driver core: class: make class_register() take a const *"), the driver core allows for struct class to be in read-only memory, so move the sg_sysfs_class structure to be declared at build time placing it into read-only memory, instead of having to be dynamically allocated at boot time. Cc: Greg Kroah-Hartman Suggested-by: Greg Kroah-Hartman Signed-off-by: Ricardo B. Marliere Link: https://lore.kernel.org/r/20240302-class_cleanup-scsi-v1-1-b9096b990e27@marliere.net Signed-off-by: Martin K. Petersen --- drivers/scsi/sg.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'drivers/scsi/sg.c') diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 86210e4dd0d3..6ef6256246df 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1424,7 +1424,9 @@ static const struct file_operations sg_fops = { .llseek = no_llseek, }; -static struct class *sg_sysfs_class; +static const struct class sg_sysfs_class = { + .name = "scsi_generic" +}; static int sg_sysfs_valid = 0; @@ -1526,7 +1528,7 @@ sg_add_device(struct device *cl_dev) if (sg_sysfs_valid) { struct device *sg_class_member; - sg_class_member = device_create(sg_sysfs_class, cl_dev->parent, + sg_class_member = device_create(&sg_sysfs_class, cl_dev->parent, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), sdp, "%s", sdp->name); @@ -1616,7 +1618,7 @@ sg_remove_device(struct device *cl_dev) read_unlock_irqrestore(&sdp->sfd_lock, iflags); sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic"); - device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index)); + device_destroy(&sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index)); cdev_del(sdp->cdev); sdp->cdev = NULL; @@ -1687,11 +1689,9 @@ init_sg(void) SG_MAX_DEVS, "sg"); if (rc) return rc; - sg_sysfs_class = class_create("scsi_generic"); - if ( IS_ERR(sg_sysfs_class) ) { - rc = PTR_ERR(sg_sysfs_class); + rc = class_register(&sg_sysfs_class); + if (rc) goto err_out; - } sg_sysfs_valid = 1; rc = scsi_register_interface(&sg_interface); if (0 == rc) { @@ -1700,7 +1700,7 @@ init_sg(void) #endif /* CONFIG_SCSI_PROC_FS */ return 0; } - class_destroy(sg_sysfs_class); + class_unregister(&sg_sysfs_class); register_sg_sysctls(); err_out: unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS); @@ -1715,7 +1715,7 @@ exit_sg(void) remove_proc_subtree("scsi/sg", NULL); #endif /* CONFIG_SCSI_PROC_FS */ scsi_unregister_interface(&sg_interface); - class_destroy(sg_sysfs_class); + class_unregister(&sg_sysfs_class); sg_sysfs_valid = 0; unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS); -- cgit v1.2.3 From 27f58c04a8f438078583041468ec60597841284d Mon Sep 17 00:00:00 2001 From: Alexander Wetzel Date: Wed, 20 Mar 2024 22:30:32 +0100 Subject: 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/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 Link: https://lore.kernel.org/r/20240320213032.18221-1-Alexander@wetzel-home.de Reviewed-by: Bart Van Assche Signed-off-by: Martin K. Petersen --- drivers/scsi/sg.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/scsi/sg.c') 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); } -- cgit v1.2.3