From b64b6bf4fd8b678a9f8477c11773c38a0a246a6d Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Thu, 2 Apr 2009 19:55:24 +0100 Subject: [PATCH] dm io: make sync_io uninterruptible If someone sends signal to a process performing synchronous dm-io call, the kernel may crash. The function sync_io attempts to exit with -EINTR if it has pending signal, however the structure "io" is allocated on stack, so already submitted io requests end up touching unallocated stack space and corrupting kernel memory. sync_io sets its state to TASK_UNINTERRUPTIBLE, so the signal can't break out of io_schedule() --- however, if the signal was pending before sync_io entered while (1) loop, the corruption of kernel memory will happen. There is no way to cancel in-progress IOs, so the best solution is to ignore signals at this point. Cc: stable@kernel.org Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- Reading git-format-patch failed