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authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>2013-09-11 14:23:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-09-11 15:58:18 -0700
commit3ddc5b46a8e90f3c9251338b60191d0a804b0d92 (patch)
tree5c76cd730cb94e75f30953d6cd1aed9386fcee37 /block/compat_ioctl.c
parent20d0e57017b69e7e4ae7166c43f3a3f023ab9702 (diff)
downloadlinux-stericsson-3ddc5b46a8e90f3c9251338b60191d0a804b0d92.tar.gz
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/compat_ioctl.c')
-rw-r--r--block/compat_ioctl.c2
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;