diff options
author | Mikulas Patocka <mpatocka@redhat.com> | 2009-04-02 19:55:24 +0100 |
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committer | Alasdair G Kergon <agk@redhat.com> | 2009-04-02 19:55:24 +0100 |
commit | b64b6bf4fd8b678a9f8477c11773c38a0a246a6d (patch) | |
tree | 26e12749b51ce21f0f59b8d7ee45a3716d2a96d8 /kernel/ns_cgroup.c | |
parent | 95f8fac8dc6139fedfb87746e0c8fda9b803cb46 (diff) |
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 <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'kernel/ns_cgroup.c')
0 files changed, 0 insertions, 0 deletions