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| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-12-16 13:42:06 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-01-09 08:32:25 +0100 |
| commit | 3f3a6bbe6f9f5e895d8945494173594ee51632da (patch) | |
| tree | 07d69582b4b05fe1b7cf99dc58ab907eb4d0113a /block | |
| parent | d024532a97db32db4b0fc4cd27c7a9ac15b84e5b (diff) | |
| download | linux-stable-3f3a6bbe6f9f5e895d8945494173594ee51632da.tar.gz linux-stable-3f3a6bbe6f9f5e895d8945494173594ee51632da.tar.bz2 linux-stable-3f3a6bbe6f9f5e895d8945494173594ee51632da.zip | |
sg_write()/bsg_write() is not fit to be called under KERNEL_DS
commit 128394eff343fc6d2f32172f03e24829539c5835 upstream.
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.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block')
| -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 d214e929ce18..b9a53615bdef 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; |