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| author | Xi Wang <xi.wang@gmail.com> | 2012-06-06 19:35:55 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-11-26 11:38:24 -0800 |
| commit | 6b71f61c321b1fe8d35b75ab573ff46c51e59acc (patch) | |
| tree | 8cf3da5771f2fb1d98fdaa84bde7ceeab4056630 | |
| parent | c66a9c7c10955499d96df63ffd87feaee6b01754 (diff) | |
| download | lwn-6b71f61c321b1fe8d35b75ab573ff46c51e59acc.tar.gz lwn-6b71f61c321b1fe8d35b75ab573ff46c51e59acc.zip | |
libceph: fix overflow in osdmap_decode()
(cherry picked from commit e91a9b639a691e0982088b5954eaafb5a25c8f1c)
On 32-bit systems, a large `n' would overflow `n * sizeof(u32)' and bypass
the check ceph_decode_need(p, end, n * sizeof(u32), bad). It would also
overflow the subsequent kmalloc() size, leading to out-of-bounds write.
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ceph/osdmap.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index 77abb1315866..a38ce3f56953 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -674,6 +674,9 @@ struct ceph_osdmap *osdmap_decode(void **p, void *end) ceph_decode_need(p, end, sizeof(u32) + sizeof(u64), bad); ceph_decode_copy(p, &pgid, sizeof(pgid)); n = ceph_decode_32(p); + err = -EINVAL; + if (n > (UINT_MAX - sizeof(*pg)) / sizeof(u32)) + goto bad; ceph_decode_need(p, end, n * sizeof(u32), bad); err = -ENOMEM; pg = kmalloc(sizeof(*pg) + n*sizeof(u32), GFP_NOFS); |