This is a note to let you know that I've just added the patch titled
netlink: put module reference if dump start fails
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: netlink-put-module-reference-if-dump-start-fails.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Tue Mar 6 19:02:12 PST 2018
From: "Jason A. Donenfeld" Jason@zx2c4.com Date: Wed, 21 Feb 2018 04:41:59 +0100 Subject: netlink: put module reference if dump start fails
From: "Jason A. Donenfeld" Jason@zx2c4.com
[ Upstream commit b87b6194be631c94785fe93398651e804ed43e28 ]
Before, if cb->start() failed, the module reference would never be put, because cb->cb_running is intentionally false at this point. Users are generally annoyed by this because they can no longer unload modules that leak references. Also, it may be possible to tediously wrap a reference counter back to zero, especially since module.c still uses atomic_inc instead of refcount_inc.
This patch expands the error path to simply call module_put if cb->start() fails.
Fixes: 41c87425a1ac ("netlink: do not set cb_running if dump's start() errs") Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netlink/af_netlink.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2276,7 +2276,7 @@ int __netlink_dump_start(struct sock *ss if (cb->start) { ret = cb->start(cb); if (ret) - goto error_unlock; + goto error_put; }
nlk->cb_running = true; @@ -2296,6 +2296,8 @@ int __netlink_dump_start(struct sock *ss */ return -EINTR;
+error_put: + module_put(control->module); error_unlock: sock_put(sk); mutex_unlock(nlk->cb_mutex);
Patches currently in stable-queue which might be from Jason@zx2c4.com are
queue-4.14/netlink-put-module-reference-if-dump-start-fails.patch
On Wed, Mar 7, 2018 at 4:30 AM, gregkh@linuxfoundation.org wrote:
queue-4.14/netlink-put-module-reference-if-dump-start-fails.patch
FYI, this patch is useful for 4.16-rc0+, 4.15+, 4.14+, 4.13.14+, and 4.9.63+. Looks like 16, 15, and 14 you have covered, and 13 you don't care about anymore. But you might want to apply this to 4.9, as it affects the in-tree net/ipv6/ila/ila_xlat.c driver, which is a tristate, meaning its refcount is affected by the bug this patch fixes. The patch appears to apply cleanly.
Jason
On Wed, Mar 07, 2018 at 06:12:13PM +0100, Jason A. Donenfeld wrote:
On Wed, Mar 7, 2018 at 4:30 AM, gregkh@linuxfoundation.org wrote:
queue-4.14/netlink-put-module-reference-if-dump-start-fails.patch
FYI, this patch is useful for 4.16-rc0+, 4.15+, 4.14+, 4.13.14+, and 4.9.63+. Looks like 16, 15, and 14 you have covered, and 13 you don't care about anymore. But you might want to apply this to 4.9, as it affects the in-tree net/ipv6/ila/ila_xlat.c driver, which is a tristate, meaning its refcount is affected by the bug this patch fixes. The patch appears to apply cleanly.
Thanks for letting me know, now queued up.
greg k-h
linux-stable-mirror@lists.linaro.org