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author | Benjamin LaHaise <bcrl@kvack.org> | 2014-06-24 13:32:51 -0400 |
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committer | Benjamin LaHaise <bcrl@kvack.org> | 2014-06-24 13:46:01 -0400 |
commit | edfbbf388f293d70bf4b7c0bc38774d05e6f711a (patch) | |
tree | 9603bc6513868d7c28052ac1e96e6bbff7121063 /fs | |
parent | f8567a3845ac05bb28f3c1b478ef752762bd39ef (diff) | |
download | linux-edfbbf388f293d70bf4b7c0bc38774d05e6f711a.tar.gz |
aio: fix kernel memory disclosure in io_getevents() introduced in v3.10
A kernel memory disclosure was introduced in aio_read_events_ring() in v3.10 by commit a31ad380bed817aa25f8830ad23e1a0480fef797. The changes made to aio_read_events_ring() failed to correctly limit the index into ctx->ring_pages[], allowing an attacked to cause the subsequent kmap() of an arbitrary page with a copy_to_user() to copy the contents into userspace. This vulnerability has been assigned CVE-2014-0206. Thanks to Mateusz and Petr for disclosing this issue. This patch applies to v3.12+. A separate backport is needed for 3.10/3.11. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Petr Matousek <pmatouse@redhat.com> Cc: Kent Overstreet <kmo@daterainc.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: stable@vger.kernel.org
Diffstat (limited to 'fs')
-rw-r--r-- | fs/aio.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/aio.c b/fs/aio.c index 6a9c7e489adf..955947ef3e02 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1063,6 +1063,9 @@ static long aio_read_events_ring(struct kioctx *ctx, if (head == tail) goto out; + head %= ctx->nr_events; + tail %= ctx->nr_events; + while (ret < nr) { long avail; struct io_event *ev; |