4.1-stable review patch. If anyone has any objections, please let me know.
------------------ From: Jeff Layton <[email protected]> commit a24221dca1868101c9b4b5adde4a6a5b1a3a64a7 upstream. If we have two tasks racing to update a mirror's credentials, then they can end up leaking one (or more) sets of credentials. The first task will set mirror->cred and then the second task will just overwrite it. Use a cmpxchg to ensure that the creds are only set once. If we get to the point where we would set mirror->cred and find that they're already set, then we just release the creds that were just found. Signed-off-by: Jeff Layton <[email protected]> Signed-off-by: Trond Myklebust <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/nfs/flexfilelayout/flexfilelayoutdev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/nfs/flexfilelayout/flexfilelayoutdev.c +++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c @@ -324,7 +324,8 @@ static int ff_layout_update_mirror_cred( __func__, PTR_ERR(cred)); return PTR_ERR(cred); } else { - mirror->cred = cred; + if (cmpxchg(&mirror->cred, NULL, cred)) + put_rpccred(cred); } } return 0; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
