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| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-12-16 13:42:06 -0500 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-02-23 03:54:47 +0000 |
| commit | 249741c2c0d7a905da66efc6d1292d3915aef1fc (patch) | |
| tree | af5d2bc4a251f147f9e13b81e1b10b3cc48058b3 /block | |
| parent | 1685cd22d7ebda79ea519457499f9cc4ced1e966 (diff) | |
| download | linux-stable-249741c2c0d7a905da66efc6d1292d3915aef1fc.tar.gz linux-stable-249741c2c0d7a905da66efc6d1292d3915aef1fc.tar.bz2 linux-stable-249741c2c0d7a905da66efc6d1292d3915aef1fc.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: Ben Hutchings <ben@decadent.org.uk>
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 ff46addde5d8..8af4880ab2a2 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -676,6 +676,9 @@ 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; |