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| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-12-16 13:42:06 -0500 |
|---|---|---|
| committer | Andreas Blaesius <skate4life@gmx.de> | 2017-05-17 19:25:36 +0200 |
| commit | 2f2242ea20d7f4e3b0d8247f2a5be2b0feb37262 (patch) | |
| tree | 2dd7546f0dbeeaf3fce757b4cc82ae8b63eb2818 | |
| parent | f4d9d78deb47216e846fa9afe01c1c72ecf09ae2 (diff) | |
| download | kernel_samsung_tuna-2f2242ea20d7f4e3b0d8247f2a5be2b0feb37262.tar.gz kernel_samsung_tuna-2f2242ea20d7f4e3b0d8247f2a5be2b0feb37262.tar.bz2 kernel_samsung_tuna-2f2242ea20d7f4e3b0d8247f2a5be2b0feb37262.zip | |
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.
Change-Id: I9fe7a5855db598eaa515007603b7e327aee74305
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | block/bsg.c | 3 | ||||
| -rw-r--r-- | drivers/scsi/sg.c | 3 |
2 files changed, 6 insertions, 0 deletions
diff --git a/block/bsg.c b/block/bsg.c index c3c4092b046..ede6acc4861 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -675,6 +675,9 @@ bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) dprintk("%s: write %Zd bytes\n", bd->name, count); + if (unlikely(segment_eq(get_fs(), KERNEL_DS))) + return -EINVAL; + bsg_set_block(bd, file); bytes_written = 0; diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 4172f891f01..819c84bec38 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -543,6 +543,9 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) sg_io_hdr_t *hp; unsigned char cmnd[MAX_COMMAND_SIZE]; + if (unlikely(segment_eq(get_fs(), KERNEL_DS))) + return -EINVAL; + if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))) return -ENXIO; SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n", |