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authorJohn Hubbard <jhubbard@nvidia.com>2018-08-23 09:16:58 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-09-12 10:14:24 +0300
commitc1a214ad82d7ac6f19fe48f90b13403b40ead9dc (patch)
treee7ca8a8b888ac979e78ca50ce7bf1582acef3894 /drivers/misc/mei
parent8d2d8935d30cc2acc57a3196dc10dfa8d5cbcdab (diff)
downloadlinux-c1a214ad82d7ac6f19fe48f90b13403b40ead9dc.tar.xz
mei: fix use-after-free in mei_cl_write
KASAN reports a use-after-free during startup, in mei_cl_write: BUG: KASAN: use-after-free in mei_cl_write+0x601/0x870 [mei] (drivers/misc/mei/client.c:1770) This is caused by commit 98e70866aacb ("mei: add support for variable length mei headers."), which changed the return value from len, to buf->size. That ends up using a stale buf pointer, because blocking call, the cb (callback) is deleted in me_cl_complete() function. However, fortunately, len remains unchanged throughout the function (and I don't see anything else that would require re-reading buf->size either), so the fix is to simply revert the change, and return len, as before. Fixes: 98e70866aacb ("mei: add support for variable length mei headers.") CC: Arnd Bergmann <arnd@arndb.de> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/mei')
-rw-r--r--drivers/misc/mei/client.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 4ab6251d418e..ebdcf0b450e2 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -1767,7 +1767,7 @@ out:
}
}
- rets = buf->size;
+ rets = len;
err:
cl_dbg(dev, cl, "rpm: autosuspend\n");
pm_runtime_mark_last_busy(dev->dev);