3.16.85-rc1 review patch. If anyone has any objections, please let me know.
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From: Ben Hutchings ben@decadent.org.uk
Change the type of next_cmd_len to unsigned char, done in upstream commit 65c26a0f3969 "sg: relax 16 byte cdb restriction".
Move the range check from sg_write() to sg_ioctl(), which was done by that commit and commit bf33f87dd04c "scsi: sg: check length passed to SG_NEXT_CMD_LEN". Continue limiting the command length to MAX_COMMAND_SIZE (16).
Signed-off-by: Ben Hutchings ben@decadent.org.uk --- --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -160,7 +160,7 @@ typedef struct sg_fd { /* holds the sta char low_dma; /* as in parent but possibly overridden to 1 */ char force_packid; /* 1 -> pack_id input to read(), 0 -> ignored */ char cmd_q; /* 1 -> allow command queuing, 0 -> don't */ - char next_cmd_len; /* 0 -> automatic (def), >0 -> use on next write() */ + unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */ char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */ char mmap_called; /* 0 -> mmap() never called on this fd */ struct kref f_ref; @@ -653,12 +653,6 @@ sg_write(struct file *filp, const char _ buf += SZ_SG_HEADER; __get_user(opcode, buf); if (sfp->next_cmd_len > 0) { - if (sfp->next_cmd_len > MAX_COMMAND_SIZE) { - SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n")); - sfp->next_cmd_len = 0; - sg_remove_request(sfp, srp); - return -EIO; - } cmd_size = sfp->next_cmd_len; sfp->next_cmd_len = 0; /* reset so only this write() effected */ } else { @@ -1045,6 +1039,8 @@ sg_ioctl(struct file *filp, unsigned int result = get_user(val, ip); if (result) return result; + if (val > MAX_COMMAND_SIZE) + return -ENOMEM; sfp->next_cmd_len = (val > 0) ? val : 0; return 0; case SG_GET_VERSION_NUM: