p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

sg_write()/bsg_write() is not fit to be called under KERNEL_DS 

Both damn things interpret userland pointers embedded into the payload;
worse, they are actually traversing those.  Leaving aside the bad
API design, this is very much _not_ safe to call with KERNEL_DS.
Bail out early if that happens.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2016-12-16 13:42:06 -05:00
parent f698cccbc8
commit 128394eff3
2 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
block/bsg.c
View File

@ -655,6 +655,9 @@ bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
dprintk("%s: write %Zd bytes\n", bd->name, count); dprintk("%s: write %Zd bytes\n", bd->name, count);
if (unlikely(segment_eq(get_fs(), KERNEL_DS)))
return -EINVAL;
bsg_set_block(bd, file); bsg_set_block(bd, file);
bytes_written = 0; bytes_written = 0;

3
drivers/scsi/sg.c
View File

@ -581,6 +581,9 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
sg_io_hdr_t *hp; sg_io_hdr_t *hp;
unsigned char cmnd[SG_MAX_CDB_SIZE]; unsigned char cmnd[SG_MAX_CDB_SIZE];
if (unlikely(segment_eq(get_fs(), KERNEL_DS)))
return -EINVAL;
if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))) if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
return -ENXIO; return -ENXIO;
SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,