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| author | Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | 2013-09-12 01:23:18 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-09-12 02:58:18 +0400 |
| commit | 3ddc5b46a8e90f3c9251338b60191d0a804b0d92 (patch) | |
| tree | 5c76cd730cb94e75f30953d6cd1aed9386fcee37 /block | |
| parent | 20d0e57017b69e7e4ae7166c43f3a3f023ab9702 (diff) | |
| download | linux-3ddc5b46a8e90f3c9251338b60191d0a804b0d92.tar.xz | |
kernel-wide: fix missing validations on __get/__put/__copy_to/__copy_from_user()
I found the following pattern that leads in to interesting findings:
grep -r "ret.*|=.*__put_user" *
grep -r "ret.*|=.*__get_user" *
grep -r "ret.*|=.*__copy" *
The __put_user() calls in compat_ioctl.c, ptrace compat, signal compat,
since those appear in compat code, we could probably expect the kernel
addresses not to be reachable in the lower 32-bit range, so I think they
might not be exploitable.
For the "__get_user" cases, I don't think those are exploitable: the worse
that can happen is that the kernel will copy kernel memory into in-kernel
buffers, and will fail immediately afterward.
The alpha csum_partial_copy_from_user() seems to be missing the
access_ok() check entirely. The fix is inspired from x86. This could
lead to information leak on alpha. I also noticed that many architectures
map csum_partial_copy_from_user() to csum_partial_copy_generic(), but I
wonder if the latter is performing the access checks on every
architectures.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'block')
| -rw-r--r-- | block/compat_ioctl.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c index 7e5d474dc6ba..fbd5a67cb773 100644 --- a/block/compat_ioctl.c +++ b/block/compat_ioctl.c @@ -70,7 +70,7 @@ static int compat_hdio_getgeo(struct gendisk *disk, struct block_device *bdev, return ret; ret = copy_to_user(ugeo, &geo, 4); - ret |= __put_user(geo.start, &ugeo->start); + ret |= put_user(geo.start, &ugeo->start); if (ret) ret = -EFAULT; |