From a16a47416d3f4f78dd8766e3278459ead45d6193 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 17 Oct 2019 20:39:18 +0100 Subject: scsi: sg: sg_ioctl(): fix copyout handling First of all, __put_user() can fail with access_ok() succeeding. And access_ok() + __copy_to_user() is spelled copy_to_user()... __put_user() *can* fail with access_ok() succeeding... Link: https://lore.kernel.org/r/20191017193925.25539-1-viro@ZenIV.linux.org.uk Signed-off-by: Al Viro Acked-by: Douglas Gilbert Signed-off-by: Martin K. Petersen --- drivers/scsi/sg.c | 43 ++++++++++++++++--------------------------- 1 file changed, 16 insertions(+), 27 deletions(-) (limited to 'drivers/scsi/sg.c') diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index cce757506383..634460421ce4 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -963,26 +963,21 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) case SG_GET_LOW_DMA: return put_user((int) sdp->device->host->unchecked_isa_dma, ip); case SG_GET_SCSI_ID: - if (!access_ok(p, sizeof (sg_scsi_id_t))) - return -EFAULT; - else { - sg_scsi_id_t __user *sg_idp = p; + { + sg_scsi_id_t v; if (atomic_read(&sdp->detaching)) return -ENODEV; - __put_user((int) sdp->device->host->host_no, - &sg_idp->host_no); - __put_user((int) sdp->device->channel, - &sg_idp->channel); - __put_user((int) sdp->device->id, &sg_idp->scsi_id); - __put_user((int) sdp->device->lun, &sg_idp->lun); - __put_user((int) sdp->device->type, &sg_idp->scsi_type); - __put_user((short) sdp->device->host->cmd_per_lun, - &sg_idp->h_cmd_per_lun); - __put_user((short) sdp->device->queue_depth, - &sg_idp->d_queue_depth); - __put_user(0, &sg_idp->unused[0]); - __put_user(0, &sg_idp->unused[1]); + memset(&v, 0, sizeof(v)); + v.host_no = sdp->device->host->host_no; + v.channel = sdp->device->channel; + v.scsi_id = sdp->device->id; + v.lun = sdp->device->lun; + v.scsi_type = sdp->device->type; + v.h_cmd_per_lun = sdp->device->host->cmd_per_lun; + v.d_queue_depth = sdp->device->queue_depth; + if (copy_to_user(p, &v, sizeof(sg_scsi_id_t))) + return -EFAULT; return 0; } case SG_SET_FORCE_PACK_ID: @@ -992,20 +987,16 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) sfp->force_packid = val ? 1 : 0; return 0; case SG_GET_PACK_ID: - if (!access_ok(ip, sizeof (int))) - return -EFAULT; read_lock_irqsave(&sfp->rq_list_lock, iflags); list_for_each_entry(srp, &sfp->rq_list, entry) { if ((1 == srp->done) && (!srp->sg_io_owned)) { read_unlock_irqrestore(&sfp->rq_list_lock, iflags); - __put_user(srp->header.pack_id, ip); - return 0; + return put_user(srp->header.pack_id, ip); } } read_unlock_irqrestore(&sfp->rq_list_lock, iflags); - __put_user(-1, ip); - return 0; + return put_user(-1, ip); case SG_GET_NUM_WAITING: read_lock_irqsave(&sfp->rq_list_lock, iflags); val = 0; @@ -1073,9 +1064,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) val = (sdp->device ? 1 : 0); return put_user(val, ip); case SG_GET_REQUEST_TABLE: - if (!access_ok(p, SZ_SG_REQ_INFO * SG_MAX_QUEUE)) - return -EFAULT; - else { + { sg_req_info_t *rinfo; rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO, @@ -1085,7 +1074,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) read_lock_irqsave(&sfp->rq_list_lock, iflags); sg_fill_request_table(sfp, rinfo); read_unlock_irqrestore(&sfp->rq_list_lock, iflags); - result = __copy_to_user(p, rinfo, + result = copy_to_user(p, rinfo, SZ_SG_REQ_INFO * SG_MAX_QUEUE); result = result ? -EFAULT : 0; kfree(rinfo); -- cgit v1.2.3 From a62726cb9cb42b366f2af2c1951ae2fff66e2ad3 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 17 Oct 2019 20:39:19 +0100 Subject: scsi: sg: sg_new_write(): replace access_ok() + __copy_from_user() with copy_from_user() Link: https://lore.kernel.org/r/20191017193925.25539-2-viro@ZenIV.linux.org.uk Signed-off-by: Al Viro Acked-by: Douglas Gilbert Signed-off-by: Martin K. Petersen --- drivers/scsi/sg.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'drivers/scsi/sg.c') diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 634460421ce4..026628aa556d 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -763,11 +763,7 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf, sg_remove_request(sfp, srp); return -EMSGSIZE; } - if (!access_ok(hp->cmdp, hp->cmd_len)) { - sg_remove_request(sfp, srp); - return -EFAULT; /* protects following copy_from_user()s + get_user()s */ - } - if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) { + if (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) { sg_remove_request(sfp, srp); return -EFAULT; } -- cgit v1.2.3 From 062c9d4527ccbdbf49139607efd44c9c3f82a2fd Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 17 Oct 2019 20:39:20 +0100 Subject: scsi: sg: sg_write(): __get_user() can fail... Link: https://lore.kernel.org/r/20191017193925.25539-3-viro@ZenIV.linux.org.uk Signed-off-by: Al Viro Acked-by: Douglas Gilbert Signed-off-by: Martin K. Petersen --- drivers/scsi/sg.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/scsi/sg.c') diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 026628aa556d..4c62237cdf37 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -640,13 +640,15 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) if (count < (SZ_SG_HEADER + 6)) return -EIO; /* The minimum scsi command length is 6 bytes. */ + buf += SZ_SG_HEADER; + if (__get_user(opcode, buf)) + return -EFAULT; + if (!(srp = sg_add_request(sfp))) { SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp, "sg_write: queue full\n")); return -EDOM; } - buf += SZ_SG_HEADER; - __get_user(opcode, buf); mutex_lock(&sfp->f_mutex); if (sfp->next_cmd_len > 0) { cmd_size = sfp->next_cmd_len; -- cgit v1.2.3 From c35a5cfb41509c2214228aa321509ffd91cbf063 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 17 Oct 2019 20:39:21 +0100 Subject: scsi: sg: sg_read(): simplify reading ->pack_id of userland sg_io_hdr_t We don't need to allocate a temporary buffer and read the entire structure in it, only to fetch a single field and free what we'd allocated. Just use get_user() and be done with it... Link: https://lore.kernel.org/r/20191017193925.25539-4-viro@ZenIV.linux.org.uk Signed-off-by: Al Viro Acked-by: Douglas Gilbert Signed-off-by: Martin K. Petersen --- drivers/scsi/sg.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) (limited to 'drivers/scsi/sg.c') diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 4c62237cdf37..2d30e89075e9 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -441,17 +441,8 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos) } if (old_hdr->reply_len < 0) { if (count >= SZ_SG_IO_HDR) { - sg_io_hdr_t *new_hdr; - new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL); - if (!new_hdr) { - retval = -ENOMEM; - goto free_old_hdr; - } - retval =__copy_from_user - (new_hdr, buf, SZ_SG_IO_HDR); - req_pack_id = new_hdr->pack_id; - kfree(new_hdr); - if (retval) { + sg_io_hdr_t __user *p = (void __user *)buf; + if (get_user(req_pack_id, &p->pack_id)) { retval = -EFAULT; goto free_old_hdr; } -- cgit v1.2.3 From d9fc5617bcb6f8278ffedd0f25bfbb697da5ca87 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 17 Oct 2019 20:39:22 +0100 Subject: scsi: sg: sg_new_write(): don't bother with access_ok ... just use copy_from_user(). We copy only SZ_SG_IO_HDR bytes, so that would, strictly speaking, loosen the check. However, for call chains via ->write() the caller has actually checked the entire range and SG_IO passes exactly SZ_SG_IO_HDR for count. So no visible behaviour changes happen if we check only what we really need for copyin. Link: https://lore.kernel.org/r/20191017193925.25539-5-viro@ZenIV.linux.org.uk Signed-off-by: Al Viro Acked-by: Douglas Gilbert Signed-off-by: Martin K. Petersen --- drivers/scsi/sg.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'drivers/scsi/sg.c') diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 2d30e89075e9..3702f66493f7 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -717,8 +717,6 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf, if (count < SZ_SG_IO_HDR) return -EINVAL; - if (!access_ok(buf, count)) - return -EFAULT; /* protects following copy_from_user()s + get_user()s */ sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */ if (!(srp = sg_add_request(sfp))) { @@ -728,7 +726,7 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf, } srp->sg_io_owned = sg_io_owned; hp = &srp->header; - if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) { + if (copy_from_user(hp, buf, SZ_SG_IO_HDR)) { sg_remove_request(sfp, srp); return -EFAULT; } -- cgit v1.2.3 From c8c12792d5fe11375af54c6bbbbebdda105eb933 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 17 Oct 2019 20:39:23 +0100 Subject: scsi: sg: sg_read(): get rid of access_ok()/__copy_..._user() Use copy_..._user() instead, both in sg_read() and in sg_read_oxfer(). And don't open-code memdup_user()... Link: https://lore.kernel.org/r/20191017193925.25539-6-viro@ZenIV.linux.org.uk Signed-off-by: Al Viro Acked-by: Douglas Gilbert Signed-off-by: Martin K. Petersen --- drivers/scsi/sg.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) (limited to 'drivers/scsi/sg.c') diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 3702f66493f7..9f6534a025cd 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -429,16 +429,10 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos) SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_read: count=%d\n", (int) count)); - if (!access_ok(buf, count)) - return -EFAULT; if (sfp->force_packid && (count >= SZ_SG_HEADER)) { - old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL); - if (!old_hdr) - return -ENOMEM; - if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) { - retval = -EFAULT; - goto free_old_hdr; - } + old_hdr = memdup_user(buf, SZ_SG_HEADER); + if (IS_ERR(old_hdr)) + return PTR_ERR(old_hdr); if (old_hdr->reply_len < 0) { if (count >= SZ_SG_IO_HDR) { sg_io_hdr_t __user *p = (void __user *)buf; @@ -529,7 +523,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos) /* Now copy the result back to the user buffer. */ if (count >= SZ_SG_HEADER) { - if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) { + if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) { retval = -EFAULT; goto free_old_hdr; } @@ -1960,12 +1954,12 @@ sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer) num = 1 << (PAGE_SHIFT + schp->page_order); for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) { if (num > num_read_xfer) { - if (__copy_to_user(outp, page_address(schp->pages[k]), + if (copy_to_user(outp, page_address(schp->pages[k]), num_read_xfer)) return -EFAULT; break; } else { - if (__copy_to_user(outp, page_address(schp->pages[k]), + if (copy_to_user(outp, page_address(schp->pages[k]), num)) return -EFAULT; num_read_xfer -= num; -- cgit v1.2.3 From a64e5a868573d6fe3b76e8d17538b10499239631 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 17 Oct 2019 20:39:24 +0100 Subject: scsi: sg: sg_write(): get rid of access_ok()/__copy_from_user()/__get_user() Just use plain copy_from_user() and get_user(). Note that while a buf-derived pointer gets stored into ->dxferp, all places that actually use the resulting value feed it either to import_iovec() or to import_single_range(), and both will do validation. Link: https://lore.kernel.org/r/20191017193925.25539-7-viro@ZenIV.linux.org.uk Signed-off-by: Al Viro Acked-by: Douglas Gilbert Signed-off-by: Martin K. Petersen --- drivers/scsi/sg.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'drivers/scsi/sg.c') diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 9f6534a025cd..f3d090b93cdf 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -612,11 +612,9 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) scsi_block_when_processing_errors(sdp->device))) return -ENXIO; - if (!access_ok(buf, count)) - return -EFAULT; /* protects following copy_from_user()s + get_user()s */ if (count < SZ_SG_HEADER) return -EIO; - if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER)) + if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER)) return -EFAULT; blocking = !(filp->f_flags & O_NONBLOCK); if (old_hdr.reply_len < 0) @@ -626,7 +624,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) return -EIO; /* The minimum scsi command length is 6 bytes. */ buf += SZ_SG_HEADER; - if (__get_user(opcode, buf)) + if (get_user(opcode, buf)) return -EFAULT; if (!(srp = sg_add_request(sfp))) { @@ -676,7 +674,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) hp->flags = input_size; /* structure abuse ... */ hp->pack_id = old_hdr.pack_id; hp->usr_ptr = NULL; - if (__copy_from_user(cmnd, buf, cmd_size)) + if (copy_from_user(cmnd, buf, cmd_size)) return -EFAULT; /* * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV, -- cgit v1.2.3 From 1feefb7ec2fe11d666f6bdca6daa7affbf9c6ce9 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 17 Oct 2019 20:39:25 +0100 Subject: scsi: sg: sg_ioctl(): get rid of access_ok() simply not needed there - neither sg_new_read() nor sg_new_write() need it. Link: https://lore.kernel.org/r/20191017193925.25539-8-viro@ZenIV.linux.org.uk Signed-off-by: Al Viro Acked-by: Douglas Gilbert Signed-off-by: Martin K. Petersen --- drivers/scsi/sg.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'drivers/scsi/sg.c') diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index f3d090b93cdf..0940abd91d3c 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -896,8 +896,6 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) return -ENODEV; if (!scsi_block_when_processing_errors(sdp->device)) return -ENXIO; - if (!access_ok(p, SZ_SG_IO_HDR)) - return -EFAULT; result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR, 1, read_only, 1, &srp); if (result < 0) -- cgit v1.2.3