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| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-12-16 19:42:06 +0100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2016-12-23 05:03:42 +0100 |
| commit | 128394eff343fc6d2f32172f03e24829539c5835 (patch) | |
| tree | 025d426075681b9904895045929e322429b8a251 /block/bsg.c | |
| parent | ufs: fix function declaration for ufs_truncate_blocks (diff) | |
| download | linux-128394eff343fc6d2f32172f03e24829539c5835.tar.xz linux-128394eff343fc6d2f32172f03e24829539c5835.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.
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'block/bsg.c')
| -rw-r--r-- | block/bsg.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/block/bsg.c b/block/bsg.c index 8a05a404ae70..a57046de2f07 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -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); + if (unlikely(segment_eq(get_fs(), KERNEL_DS))) + return -EINVAL; + bsg_set_block(bd, file); bytes_written = 0; |